Would you build this DIY project?

[Paul Stamler]

Hi folks:

Let me launch a trial balloon here. Is this a DIY project that appeals to
you?

It's a microphone preamp, solid state, transformer in (Jensen),
transformerless balanced +4dBu out with a separate -10dBV unbalanced out. IC
based, up to 8 channels in a 2U case, plus separate power pack. Phantom on
all channels, 100Hz rolloff selectable on all channels, otherwise no EQ.
Designed to be comparable to the Sytek in price, performance and feature
set, but with transformer-coupled inputs. All parts obtainable (to North
Americans, at any rate) from Digi-Key and Allied Electronics, except for the
transformers, which come directly from Jensen. On-card regulation. Like the
Sytek, there are some optional choices in what ICs you use.

Approximate costs are as follows. These include everything except the cases,
which are up to you. At the moment I'm assuming the PC boards would cost
$25.00 / ea.; that's the biggest unknown in the equation. I can't really
fill that in until I design the boards, and I'm not gonna do that until I
find out whether anybody's interested. (Also, of course, price of the boards
will vary depending on how many I order.) There are options which will raise
the price, and some that will lower it, but this is the basic design.

Each input channel: $220.00

Power Supply: $120.00

So a 4-channel unit would cost almost exactly $1k, not counting boxes. An
8-channel would be $1880, ditto. I'd make my slice selling the PC boards and
writing it up for the magazines.

Any interest?

Peace,
Paul

[Mike Rivers]

In article > writes:

> Let me launch a trial balloon here. Is this a DIY project that appeals to
> you?
>
> It's a microphone preamp, solid state, transformer in (Jensen),
> transformerless balanced +4dBu out with a separate -10dBV unbalanced out. IC
> based, up to 8 channels in a 2U case, plus separate power pack. Phantom on
> all channels, 100Hz rolloff selectable on all channels, otherwise no EQ.
> Designed to be comparable to the Sytek in price, performance and feature
> set, but with transformer-coupled inputs.

> So a 4-channel unit would cost almost exactly $1k, not counting boxes. An
> 8-channel would be $1880, ditto. I'd make my slice selling the PC boards and
> writing it up for the magazines.

I think that the average DIYer today would find that to be too much
cash to put into a project, particularly since it involves a case and
considerable metalworking skill to make a unit that looks decent. You
might sell about ten, and you know what Recording pays for articles.
<g>




--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> Let me launch a trial balloon here. Is this a DIY project that appeals to
> you?
>
> It's a microphone preamp, solid state, transformer in (Jensen),
> transformerless balanced +4dBu out with a separate -10dBV unbalanced out. IC
> based, up to 8 channels in a 2U case, plus separate power pack. Phantom on
> all channels, 100Hz rolloff selectable on all channels, otherwise no EQ.
> Designed to be comparable to the Sytek in price, performance and feature
> set, but with transformer-coupled inputs.

> So a 4-channel unit would cost almost exactly $1k, not counting boxes. An
> 8-channel would be $1880, ditto. I'd make my slice selling the PC boards and
> writing it up for the magazines.

I think that the average DIYer today would find that to be too much
cash to put into a project, particularly since it involves a case and
considerable metalworking skill to make a unit that looks decent. You
might sell about ten, and you know what Recording pays for articles.
<g>




--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Richard Crowley]

"Paul Stamler" wrote ...
> Let me launch a trial balloon here. Is this a DIY project that
> appeals to you?

Yes, it would appeal to me as a DIY project.
I'd appreciate a bit more detail on the $220/channel costing.

[Richard Crowley]

"Paul Stamler" wrote ...
> Let me launch a trial balloon here. Is this a DIY project that
> appeals to you?

Yes, it would appeal to me as a DIY project.
I'd appreciate a bit more detail on the $220/channel costing.

[Garrett Cox]

How much to build the powersupply? I assume we'd be building it. I'd be
interested. I love reading the DIY also. Still want to piece together a
few of Scott Dorsey's passive EQ's. I hope it'd sound pretty awesome
220 per channel is a bit of cash. I won't say steep but it is a DIY
project for almost 2 grand. (If you do 8 channels)

mark me down for interest peaked.

On 2004-11-12 12:48:21 -0800, "Paul Stamler" > said:

> Hi folks:
>
> Let me launch a trial balloon here. Is this a DIY project that appeals to
> you?
>
> It's a microphone preamp, solid state, transformer in (Jensen),
> transformerless balanced +4dBu out with a separate -10dBV unbalanced out. IC
> based, up to 8 channels in a 2U case, plus separate power pack. Phantom on
> all channels, 100Hz rolloff selectable on all channels, otherwise no EQ.
> Designed to be comparable to the Sytek in price, performance and feature
> set, but with transformer-coupled inputs. All parts obtainable (to North
> Americans, at any rate) from Digi-Key and Allied Electronics, except for the
> transformers, which come directly from Jensen. On-card regulation. Like the
> Sytek, there are some optional choices in what ICs you use.
>
> Approximate costs are as follows. These include everything except the cases,
> which are up to you. At the moment I'm assuming the PC boards would cost
> $25.00 / ea.; that's the biggest unknown in the equation. I can't really
> fill that in until I design the boards, and I'm not gonna do that until I
> find out whether anybody's interested. (Also, of course, price of the boards
> will vary depending on how many I order.) There are options which will raise
> the price, and some that will lower it, but this is the basic design.
>
> Each input channel: $220.00
>
> Power Supply: $120.00
>
> So a 4-channel unit would cost almost exactly $1k, not counting boxes. An
> 8-channel would be $1880, ditto. I'd make my slice selling the PC boards and
> writing it up for the magazines.
>
> Any interest?
>
> Peace,
> Paul

[Garrett Cox]

How much to build the powersupply? I assume we'd be building it. I'd be
interested. I love reading the DIY also. Still want to piece together a
few of Scott Dorsey's passive EQ's. I hope it'd sound pretty awesome
220 per channel is a bit of cash. I won't say steep but it is a DIY
project for almost 2 grand. (If you do 8 channels)

mark me down for interest peaked.

On 2004-11-12 12:48:21 -0800, "Paul Stamler" > said:

> Hi folks:
>
> Let me launch a trial balloon here. Is this a DIY project that appeals to
> you?
>
> It's a microphone preamp, solid state, transformer in (Jensen),
> transformerless balanced +4dBu out with a separate -10dBV unbalanced out. IC
> based, up to 8 channels in a 2U case, plus separate power pack. Phantom on
> all channels, 100Hz rolloff selectable on all channels, otherwise no EQ.
> Designed to be comparable to the Sytek in price, performance and feature
> set, but with transformer-coupled inputs. All parts obtainable (to North
> Americans, at any rate) from Digi-Key and Allied Electronics, except for the
> transformers, which come directly from Jensen. On-card regulation. Like the
> Sytek, there are some optional choices in what ICs you use.
>
> Approximate costs are as follows. These include everything except the cases,
> which are up to you. At the moment I'm assuming the PC boards would cost
> $25.00 / ea.; that's the biggest unknown in the equation. I can't really
> fill that in until I design the boards, and I'm not gonna do that until I
> find out whether anybody's interested. (Also, of course, price of the boards
> will vary depending on how many I order.) There are options which will raise
> the price, and some that will lower it, but this is the basic design.
>
> Each input channel: $220.00
>
> Power Supply: $120.00
>
> So a 4-channel unit would cost almost exactly $1k, not counting boxes. An
> 8-channel would be $1880, ditto. I'd make my slice selling the PC boards and
> writing it up for the magazines.
>
> Any interest?
>
> Peace,
> Paul

[Garrett Cox]

You could probably find a suitable Bud box for it. I do agree the
pricing is something to consider still.

cheers

garrett


On 2004-11-12 17:37:14 -0800, (Mike Rivers) said:
> I think that the average DIYer today would find that to be too much
> cash to put into a project, particularly since it involves a case and
> considerable metalworking skill to make a unit that looks decent. You
> might sell about ten, and you know what Recording pays for articles.
> <g>

[Garrett Cox]

You could probably find a suitable Bud box for it. I do agree the
pricing is something to consider still.

cheers

garrett


On 2004-11-12 17:37:14 -0800, (Mike Rivers) said:
> I think that the average DIYer today would find that to be too much
> cash to put into a project, particularly since it involves a case and
> considerable metalworking skill to make a unit that looks decent. You
> might sell about ten, and you know what Recording pays for articles.
> <g>

[Brian Allen]

You might try bouncing this around at the 'lab' forum at prodigy. There
is a lot of pro audio DIY stuff going on there.

http://www.prodigy-pro.com/forum/index.php

Brian



Paul Stamler wrote:
> Hi folks:
>
> Let me launch a trial balloon here. Is this a DIY project that appeals to
> you?
>
> It's a microphone preamp, solid state, transformer in (Jensen),
> transformerless balanced +4dBu out with a separate -10dBV unbalanced out. IC
> based, up to 8 channels in a 2U case, plus separate power pack. Phantom on
> all channels, 100Hz rolloff selectable on all channels, otherwise no EQ.
> Designed to be comparable to the Sytek in price, performance and feature
> set, but with transformer-coupled inputs. All parts obtainable (to North
> Americans, at any rate) from Digi-Key and Allied Electronics, except for the
> transformers, which come directly from Jensen. On-card regulation. Like the
> Sytek, there are some optional choices in what ICs you use.
>
> Approximate costs are as follows. These include everything except the cases,
> which are up to you. At the moment I'm assuming the PC boards would cost
> $25.00 / ea.; that's the biggest unknown in the equation. I can't really
> fill that in until I design the boards, and I'm not gonna do that until I
> find out whether anybody's interested. (Also, of course, price of the boards
> will vary depending on how many I order.) There are options which will raise
> the price, and some that will lower it, but this is the basic design.
>
> Each input channel: $220.00
>
> Power Supply: $120.00
>
> So a 4-channel unit would cost almost exactly $1k, not counting boxes. An
> 8-channel would be $1880, ditto. I'd make my slice selling the PC boards and
> writing it up for the magazines.
>
> Any interest?
>
> Peace,
> Paul
>
>

[Brian Allen]

You might try bouncing this around at the 'lab' forum at prodigy. There
is a lot of pro audio DIY stuff going on there.

http://www.prodigy-pro.com/forum/index.php

Brian



Paul Stamler wrote:
> Hi folks:
>
> Let me launch a trial balloon here. Is this a DIY project that appeals to
> you?
>
> It's a microphone preamp, solid state, transformer in (Jensen),
> transformerless balanced +4dBu out with a separate -10dBV unbalanced out. IC
> based, up to 8 channels in a 2U case, plus separate power pack. Phantom on
> all channels, 100Hz rolloff selectable on all channels, otherwise no EQ.
> Designed to be comparable to the Sytek in price, performance and feature
> set, but with transformer-coupled inputs. All parts obtainable (to North
> Americans, at any rate) from Digi-Key and Allied Electronics, except for the
> transformers, which come directly from Jensen. On-card regulation. Like the
> Sytek, there are some optional choices in what ICs you use.
>
> Approximate costs are as follows. These include everything except the cases,
> which are up to you. At the moment I'm assuming the PC boards would cost
> $25.00 / ea.; that's the biggest unknown in the equation. I can't really
> fill that in until I design the boards, and I'm not gonna do that until I
> find out whether anybody's interested. (Also, of course, price of the boards
> will vary depending on how many I order.) There are options which will raise
> the price, and some that will lower it, but this is the basic design.
>
> Each input channel: $220.00
>
> Power Supply: $120.00
>
> So a 4-channel unit would cost almost exactly $1k, not counting boxes. An
> 8-channel would be $1880, ditto. I'd make my slice selling the PC boards and
> writing it up for the magazines.
>
> Any interest?
>
> Peace,
> Paul
>
>

[Scott Dorsey]

In article <znr1100301967k@trad>, Mike Rivers > wrote:
>
>I think that the average DIYer today would find that to be too much
>cash to put into a project, particularly since it involves a case and
>considerable metalworking skill to make a unit that looks decent. You
>might sell about ten, and you know what Recording pays for articles.
><g>

Skip the input transformer. Go transformerless with the THAT large area
transistors, and save fifty bucks a channel that way.

Get prepunched cases available from SESCOM or one of the other custom
cabinet guys. That's the real rub on these things and it's also a substantial
part of the total cost.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

In article <znr1100301967k@trad>, Mike Rivers > wrote:
>
>I think that the average DIYer today would find that to be too much
>cash to put into a project, particularly since it involves a case and
>considerable metalworking skill to make a unit that looks decent. You
>might sell about ten, and you know what Recording pays for articles.
><g>

Skip the input transformer. Go transformerless with the THAT large area
transistors, and save fifty bucks a channel that way.

Get prepunched cases available from SESCOM or one of the other custom
cabinet guys. That's the real rub on these things and it's also a substantial
part of the total cost.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[agent86]

Mike Rivers wrote:

> I think that the average DIYer today would find that to be too much
> cash to put into a project, particularly since it involves a case and
> considerable metalworking skill to make a unit that looks decent.

Very true. With the RNP going for $475 new, what's the point (unless you
just absolutely HAVE to have transformers). And why would you reall NEED
transformers at that price point, since Shure 57s behave themselves pretty
well with the RNP?

[agent86]

Mike Rivers wrote:

> I think that the average DIYer today would find that to be too much
> cash to put into a project, particularly since it involves a case and
> considerable metalworking skill to make a unit that looks decent.

Very true. With the RNP going for $475 new, what's the point (unless you
just absolutely HAVE to have transformers). And why would you reall NEED
transformers at that price point, since Shure 57s behave themselves pretty
well with the RNP?

[Paul Stamler]

"Richard Crowley" > wrote in message
...
> "Paul Stamler" wrote ...
> > Let me launch a trial balloon here. Is this a DIY project that
> > appeals to you?
>
> Yes, it would appeal to me as a DIY project.
> I'd appreciate a bit more detail on the $220/channel costing.

Uh, whoops -- I added something in twice. The cost would be closer to
$175/channel. The design is a slimmed-down version of the "project-r" preamp
I published in Recording several years ago. So 4 channels would cost $700,
plus $140 for the power supply (that just went up -- sorry, this is still
not quite a finished design) and whatever you wanted to spend for the boxes.
$840 total; $1540 for 8 channels.

The $175/channel breaks down this way (all figures rounded to nearest US$):

Circuit board - $25 (that part's guesswork).

Transformer - $67.

Stage 1 - $33-36, depending on choice of chip. The bulk of that cost is the
XLR, level control, and switches for the bass rolloff and the phantom
on/off.

Stage 2 - $15.

Balanced output - $16.

On-card regulators - $18.

About the raw supply for $120: I freely admit it's over-designed. In the
previous design I had a fairly normal power supply (with tons of
capacitance) and a very fancy, two-stage regulator (317/337 pre-regulators
in the box, plus Sulzer-type op-amp+pass-transistor regulators on the cards.
That was fun, but it led some builders to problems; the same circuits that
stayed perfectly stable for me, oscillated like crazy for them. Turns out I
was using an older version of the 5534 chip in the regulators (Signetics),
which is no longer available. The new ones are less stable in that circuit.
Most of the folks who built the preamp ended up using TL071s in the
regulators. But I digress.

The new raw supply is one which pays somewhat fanatical attention to
RFI-proofing, including filtering out the crud that comes from the diodes'
switching off, and it incorporates some interesting things I learned about
capacitors while researching an article which audioXpress will, I hope,
manage to get into print soon. You probably could save several dollars on it
if you have a good source of surplus 48VCT transformers handy. Or surplus
5-pin XLRs, chassis and cable mount, for the umbilicus.

There are other ways of spending less on this design, notably by omitting
the bass rolloff and/or phantom switches. There are a few ways of spending
more, too, and getting higher performance, including fancier opamps in Stage
2 and substituting an LT1085 regulator for the LM317 on each card.

Anyway, that's the bottom line, or family of them: About $175 for each
channel, assuming my PC board number is right, about $140 for the power
supply. Add boxes.

As to Scott's suggestion of going transformerless: Why? For about the same
amount of money I can get 4 or 8 channels of Sytek, which is excellent. The
point of this design is to give a similar level of performance for those of
us who want to use transformer-coupled inputs, for reasons of RFI-proofness,
loading, whatever.


Peace,
Paul

[Paul Stamler]

"Richard Crowley" > wrote in message
...
> "Paul Stamler" wrote ...
> > Let me launch a trial balloon here. Is this a DIY project that
> > appeals to you?
>
> Yes, it would appeal to me as a DIY project.
> I'd appreciate a bit more detail on the $220/channel costing.

Uh, whoops -- I added something in twice. The cost would be closer to
$175/channel. The design is a slimmed-down version of the "project-r" preamp
I published in Recording several years ago. So 4 channels would cost $700,
plus $140 for the power supply (that just went up -- sorry, this is still
not quite a finished design) and whatever you wanted to spend for the boxes.
$840 total; $1540 for 8 channels.

The $175/channel breaks down this way (all figures rounded to nearest US$):

Circuit board - $25 (that part's guesswork).

Transformer - $67.

Stage 1 - $33-36, depending on choice of chip. The bulk of that cost is the
XLR, level control, and switches for the bass rolloff and the phantom
on/off.

Stage 2 - $15.

Balanced output - $16.

On-card regulators - $18.

About the raw supply for $120: I freely admit it's over-designed. In the
previous design I had a fairly normal power supply (with tons of
capacitance) and a very fancy, two-stage regulator (317/337 pre-regulators
in the box, plus Sulzer-type op-amp+pass-transistor regulators on the cards.
That was fun, but it led some builders to problems; the same circuits that
stayed perfectly stable for me, oscillated like crazy for them. Turns out I
was using an older version of the 5534 chip in the regulators (Signetics),
which is no longer available. The new ones are less stable in that circuit.
Most of the folks who built the preamp ended up using TL071s in the
regulators. But I digress.

The new raw supply is one which pays somewhat fanatical attention to
RFI-proofing, including filtering out the crud that comes from the diodes'
switching off, and it incorporates some interesting things I learned about
capacitors while researching an article which audioXpress will, I hope,
manage to get into print soon. You probably could save several dollars on it
if you have a good source of surplus 48VCT transformers handy. Or surplus
5-pin XLRs, chassis and cable mount, for the umbilicus.

There are other ways of spending less on this design, notably by omitting
the bass rolloff and/or phantom switches. There are a few ways of spending
more, too, and getting higher performance, including fancier opamps in Stage
2 and substituting an LT1085 regulator for the LM317 on each card.

Anyway, that's the bottom line, or family of them: About $175 for each
channel, assuming my PC board number is right, about $140 for the power
supply. Add boxes.

As to Scott's suggestion of going transformerless: Why? For about the same
amount of money I can get 4 or 8 channels of Sytek, which is excellent. The
point of this design is to give a similar level of performance for those of
us who want to use transformer-coupled inputs, for reasons of RFI-proofness,
loading, whatever.


Peace,
Paul

[Paul Stamler]

"agent86" > wrote in message
.. .
> Mike Rivers wrote:
>
> > I think that the average DIYer today would find that to be too much
> > cash to put into a project, particularly since it involves a case and
> > considerable metalworking skill to make a unit that looks decent.
>
> Very true. With the RNP going for $475 new, what's the point (unless you
> just absolutely HAVE to have transformers). And why would you reall NEED
> transformers at that price point, since Shure 57s behave themselves pretty
> well with the RNP?

Revised cost estimate:

2 ch.: $490
4 ch.: $840
8 ch.: $1540

The idea is to provide up to 8 channels of preamp in a 2U box (plus the
outboard power supply). 8 in a box for compactness, particularly for people
doing remote work, or for folks who just want 8 identical good-quality
preamps. It seems to be a pretty popular format at several price points; the
one thing I notice, though, is that none of the 8-bangers out there are
transformer-coupled, and some of us like transformers, for (as I mentioned)
RFI-proofing, loading, whatever. So I'm looking to see whether there's a
niche here. There wouldn't be, I don't think, for a manufactured version of
this; the price would be prohibitive. But perhaps as a DIY it might slip in.
So I'm running it up the flagpole.

Peace,
Paul

[Paul Stamler]

"agent86" > wrote in message
.. .
> Mike Rivers wrote:
>
> > I think that the average DIYer today would find that to be too much
> > cash to put into a project, particularly since it involves a case and
> > considerable metalworking skill to make a unit that looks decent.
>
> Very true. With the RNP going for $475 new, what's the point (unless you
> just absolutely HAVE to have transformers). And why would you reall NEED
> transformers at that price point, since Shure 57s behave themselves pretty
> well with the RNP?

Revised cost estimate:

2 ch.: $490
4 ch.: $840
8 ch.: $1540

The idea is to provide up to 8 channels of preamp in a 2U box (plus the
outboard power supply). 8 in a box for compactness, particularly for people
doing remote work, or for folks who just want 8 identical good-quality
preamps. It seems to be a pretty popular format at several price points; the
one thing I notice, though, is that none of the 8-bangers out there are
transformer-coupled, and some of us like transformers, for (as I mentioned)
RFI-proofing, loading, whatever. So I'm looking to see whether there's a
niche here. There wouldn't be, I don't think, for a manufactured version of
this; the price would be prohibitive. But perhaps as a DIY it might slip in.
So I'm running it up the flagpole.

Peace,
Paul

[Mike Rivers]

In article > Garrett Cox writes:

> You could probably find a suitable Bud box for it. I do agree the
> pricing is something to consider still.

If you're going to build something that costs $2,000 or more, you want
to put it in a box that makes it look like $2,000, with all the round
holes round, and lined up straight. And you probably want engraved or
silkscreened legends rather than strips of label tape. One of the
things about undertaking a DIY project (and our furniture-building
friends will surely agree) is not just to make something cheap or to
make something that you can't buy easily, but to make something that
you're proud of - whether it's a mic preamp, a custom cable, or a set
of shelves to store your backups.

There are a couple of companies that advertise in the trade magazines
that custom-punched engraved panels but that's still pretty expensive.
Markertek is one. Hammond makes a nice rack-mount case for
construction projects. A 2-space one runs between $55 and $90
depending on depth and venting.

Power supplies are probably best bought given the difficulty with
finding suitable transformers. That would be in the $100-150 range for
bi-polar 15 to 24 volts plus a single 48 volt supply. You'd need a
chassis or case for those, too.


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > Garrett Cox writes:

> You could probably find a suitable Bud box for it. I do agree the
> pricing is something to consider still.

If you're going to build something that costs $2,000 or more, you want
to put it in a box that makes it look like $2,000, with all the round
holes round, and lined up straight. And you probably want engraved or
silkscreened legends rather than strips of label tape. One of the
things about undertaking a DIY project (and our furniture-building
friends will surely agree) is not just to make something cheap or to
make something that you can't buy easily, but to make something that
you're proud of - whether it's a mic preamp, a custom cable, or a set
of shelves to store your backups.

There are a couple of companies that advertise in the trade magazines
that custom-punched engraved panels but that's still pretty expensive.
Markertek is one. Hammond makes a nice rack-mount case for
construction projects. A 2-space one runs between $55 and $90
depending on depth and venting.

Power supplies are probably best bought given the difficulty with
finding suitable transformers. That would be in the $100-150 range for
bi-polar 15 to 24 volts plus a single 48 volt supply. You'd need a
chassis or case for those, too.


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Magnus Jans?n]

"Paul Stamler" > wrote in message >...
> Hi folks:
>
> Let me launch a trial balloon here. Is this a DIY project that appeals to
> you?

(snip)

Hi.

I have some general opinions on magazine-published DIY projects, and
this is aimed not only at Mr Stamler but also Mr Dorsey and everyone
else that do these things.

First, I want to be able to get ALL parts at once from one place, and
that must include the chassis. In case you didn't know this, most
people don't have the tools to drill in metal when it comes to the
diameters needed for XLR connectors.
I want to whip out my credit card, order one neat package with
EVERYTHING in it and sit down a couple of hours every sunday to
assemble. I don't have the time or inclination to order parts from 4
different sources, hunt for a suitable chassi, deal with back-orders
and replacements, pay $30 in shipping for 3 resistors etc.
I know you guys don't want to turn your kitchen into a stocking room
for Digi-key parts, but I'm telling you - when I read "You have to
order this and that from here and there plus machine your own case" I
simply flip the page. And I'm not alone.


Second, I don't think anyone is interested in merly "decent" or
"servicable" projects. I think most readers have too much of that
already. We want "really good" or even "outstanding".
To keep price down I think you need to make costly features optional.
Many people couldn't care less about HP-filtering, phase switches,
metering and balanced outputs in a preamp for instance.

Here are some DIY-projects that I would like to see (and if they have
already been published, please tell me which issue they are in):

-Parametric EQ for live use. A clean parametric EQ with very narrow
bands for full-program corrective live use.

-A/D and D/A converter. There is a remarkable black hole in the market
for stand-alone 2ch converters in the sub $1000 area. I'm sure there
are economical reasons for this but if a DIY project could fit in
there it would be wonderful.

-A "Re-amping" capable DI box. In fact, it wouldn't have to be able to
do normal DI at all.

/Magnus

[Magnus Jans?n]

"Paul Stamler" > wrote in message >...
> Hi folks:
>
> Let me launch a trial balloon here. Is this a DIY project that appeals to
> you?

(snip)

Hi.

I have some general opinions on magazine-published DIY projects, and
this is aimed not only at Mr Stamler but also Mr Dorsey and everyone
else that do these things.

First, I want to be able to get ALL parts at once from one place, and
that must include the chassis. In case you didn't know this, most
people don't have the tools to drill in metal when it comes to the
diameters needed for XLR connectors.
I want to whip out my credit card, order one neat package with
EVERYTHING in it and sit down a couple of hours every sunday to
assemble. I don't have the time or inclination to order parts from 4
different sources, hunt for a suitable chassi, deal with back-orders
and replacements, pay $30 in shipping for 3 resistors etc.
I know you guys don't want to turn your kitchen into a stocking room
for Digi-key parts, but I'm telling you - when I read "You have to
order this and that from here and there plus machine your own case" I
simply flip the page. And I'm not alone.


Second, I don't think anyone is interested in merly "decent" or
"servicable" projects. I think most readers have too much of that
already. We want "really good" or even "outstanding".
To keep price down I think you need to make costly features optional.
Many people couldn't care less about HP-filtering, phase switches,
metering and balanced outputs in a preamp for instance.

Here are some DIY-projects that I would like to see (and if they have
already been published, please tell me which issue they are in):

-Parametric EQ for live use. A clean parametric EQ with very narrow
bands for full-program corrective live use.

-A/D and D/A converter. There is a remarkable black hole in the market
for stand-alone 2ch converters in the sub $1000 area. I'm sure there
are economical reasons for this but if a DIY project could fit in
there it would be wonderful.

-A "Re-amping" capable DI box. In fact, it wouldn't have to be able to
do normal DI at all.

/Magnus

[Jedd Haas]

In article >,
(Magnus Jans?n) wrote:

> "Paul Stamler" > wrote in message
>...
> > Hi folks:
> >
> > Let me launch a trial balloon here. Is this a DIY project that appeals to
> > you?
>
> (snip)

[snip]
> Second, I don't think anyone is interested in merly "decent" or
> "servicable" projects. I think most readers have too much of that
> already. We want "really good" or even "outstanding".

This comment hits at the key (potential) problem I see with this project.
Conceptually, it seems similar to the Seventh Circle and Hamptone kits.
The difference seems to be that you are suggesting "comparable to Sytek"
performance. I haven't used the Sytek, but most commenters here suggest
it's "mid-range" in quality. The Seventh Circle preamps aim for "Neve" and
"API" quality, which is clearly a step up. Those guys also offer complete
kits with all the parts, including chassis.

These comments are not meant to dog your idea, just pointing out what's
available and (somewhat) comparable to your idea. It seems to me that,
while the other guys do have a higher cost per channel, they are offering
complete kits and (alleged) higher quality. For myself, given the only
moderate cost differences between your suggested kit and the others, I
would probably buy the Hamptone or Seventh Circle kits; if I'm going to
take the time to build it, I want something as good as (or
better/different) than what I have now (API).

Hamptone and 7C also seem to offer pretty good tech support; are you
looking to do this as an ongoing business where the sales volume is strong
enough to provide comparable support? If not, the other alternative might
be to offer a "PC board only" kit, or a kit with the board and a few
critical parts.

--
Jedd Haas - Artist
http://www.gallerytungsten.com
http://www.epsno.com

[Jedd Haas]

In article >,
(Magnus Jans?n) wrote:

> "Paul Stamler" > wrote in message
>...
> > Hi folks:
> >
> > Let me launch a trial balloon here. Is this a DIY project that appeals to
> > you?
>
> (snip)

[snip]
> Second, I don't think anyone is interested in merly "decent" or
> "servicable" projects. I think most readers have too much of that
> already. We want "really good" or even "outstanding".

This comment hits at the key (potential) problem I see with this project.
Conceptually, it seems similar to the Seventh Circle and Hamptone kits.
The difference seems to be that you are suggesting "comparable to Sytek"
performance. I haven't used the Sytek, but most commenters here suggest
it's "mid-range" in quality. The Seventh Circle preamps aim for "Neve" and
"API" quality, which is clearly a step up. Those guys also offer complete
kits with all the parts, including chassis.

These comments are not meant to dog your idea, just pointing out what's
available and (somewhat) comparable to your idea. It seems to me that,
while the other guys do have a higher cost per channel, they are offering
complete kits and (alleged) higher quality. For myself, given the only
moderate cost differences between your suggested kit and the others, I
would probably buy the Hamptone or Seventh Circle kits; if I'm going to
take the time to build it, I want something as good as (or
better/different) than what I have now (API).

Hamptone and 7C also seem to offer pretty good tech support; are you
looking to do this as an ongoing business where the sales volume is strong
enough to provide comparable support? If not, the other alternative might
be to offer a "PC board only" kit, or a kit with the board and a few
critical parts.

--
Jedd Haas - Artist
http://www.gallerytungsten.com
http://www.epsno.com

[Scott Dorsey]

Magnus Jans?n > wrote:
>
>-Parametric EQ for live use. A clean parametric EQ with very narrow
>bands for full-program corrective live use.

I can't do this as cheaply as you can buy them right now. I am seeing
Orbans selling for next to nothing on the used market. Nobody seems to
want used parametrics.

>-A/D and D/A converter. There is a remarkable black hole in the market
>for stand-alone 2ch converters in the sub $1000 area. I'm sure there
>are economical reasons for this but if a DIY project could fit in
>there it would be wonderful.

For a D/A, there is Sheldon Stokes' project at www.quadesl.com. I built
one and it sounds great. Tell him you want him to do an A/D as well. I
keep bugging him about that and it's not high on his list.

>-A "Re-amping" capable DI box. In fact, it wouldn't have to be able to
>do normal DI at all.

Hell, that is an easy article that will take an afternoon to whip out.
It's a Tamura transformer and a couple resistors.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Magnus Jans?n > wrote:
>
>-Parametric EQ for live use. A clean parametric EQ with very narrow
>bands for full-program corrective live use.

I can't do this as cheaply as you can buy them right now. I am seeing
Orbans selling for next to nothing on the used market. Nobody seems to
want used parametrics.

>-A/D and D/A converter. There is a remarkable black hole in the market
>for stand-alone 2ch converters in the sub $1000 area. I'm sure there
>are economical reasons for this but if a DIY project could fit in
>there it would be wonderful.

For a D/A, there is Sheldon Stokes' project at www.quadesl.com. I built
one and it sounds great. Tell him you want him to do an A/D as well. I
keep bugging him about that and it's not high on his list.

>-A "Re-amping" capable DI box. In fact, it wouldn't have to be able to
>do normal DI at all.

Hell, that is an easy article that will take an afternoon to whip out.
It's a Tamura transformer and a couple resistors.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[normanstrong]

"Paul Stamler" > wrote in message
...
> Hi folks:
>
> Let me launch a trial balloon here. Is this a DIY project that
appeals to
> you?
>
> It's a microphone preamp, solid state, transformer in (Jensen),
> transformerless balanced +4dBu out with a separate -10dBV unbalanced
out. IC
> based, up to 8 channels in a 2U case, plus separate power pack.
Phantom on
> all channels, 100Hz rolloff selectable on all channels, otherwise no
EQ.
> Designed to be comparable to the Sytek in price, performance and
feature
> set, but with transformer-coupled inputs. All parts obtainable (to
North
> Americans, at any rate) from Digi-Key and Allied Electronics, except
for the
> transformers, which come directly from Jensen. On-card regulation.
Like the
> Sytek, there are some optional choices in what ICs you use.
>
> Approximate costs are as follows. These include everything except
the cases,
> which are up to you. At the moment I'm assuming the PC boards would
cost
> $25.00 / ea.; that's the biggest unknown in the equation. I can't
really
> fill that in until I design the boards, and I'm not gonna do that
until I
> find out whether anybody's interested. (Also, of course, price of
the boards
> will vary depending on how many I order.) There are options which
will raise
> the price, and some that will lower it, but this is the basic
design.
>
> Each input channel: $220.00
>
> Power Supply: $120.00
>
> So a 4-channel unit would cost almost exactly $1k, not counting
boxes. An
> 8-channel would be $1880, ditto. I'd make my slice selling the PC
boards and
> writing it up for the magazines.

None whatsoever. There are already too many high-priced mike preamps
on the market (from the point of view of manufacturers.) If you want
to design something useful, come up with a battery operated unit at
$50/channel.

Norm Strong

[normanstrong]

"Paul Stamler" > wrote in message
...
> Hi folks:
>
> Let me launch a trial balloon here. Is this a DIY project that
appeals to
> you?
>
> It's a microphone preamp, solid state, transformer in (Jensen),
> transformerless balanced +4dBu out with a separate -10dBV unbalanced
out. IC
> based, up to 8 channels in a 2U case, plus separate power pack.
Phantom on
> all channels, 100Hz rolloff selectable on all channels, otherwise no
EQ.
> Designed to be comparable to the Sytek in price, performance and
feature
> set, but with transformer-coupled inputs. All parts obtainable (to
North
> Americans, at any rate) from Digi-Key and Allied Electronics, except
for the
> transformers, which come directly from Jensen. On-card regulation.
Like the
> Sytek, there are some optional choices in what ICs you use.
>
> Approximate costs are as follows. These include everything except
the cases,
> which are up to you. At the moment I'm assuming the PC boards would
cost
> $25.00 / ea.; that's the biggest unknown in the equation. I can't
really
> fill that in until I design the boards, and I'm not gonna do that
until I
> find out whether anybody's interested. (Also, of course, price of
the boards
> will vary depending on how many I order.) There are options which
will raise
> the price, and some that will lower it, but this is the basic
design.
>
> Each input channel: $220.00
>
> Power Supply: $120.00
>
> So a 4-channel unit would cost almost exactly $1k, not counting
boxes. An
> 8-channel would be $1880, ditto. I'd make my slice selling the PC
boards and
> writing it up for the magazines.

None whatsoever. There are already too many high-priced mike preamps
on the market (from the point of view of manufacturers.) If you want
to design something useful, come up with a battery operated unit at
$50/channel.

Norm Strong

[normanstrong]

<Garrett Cox> wrote in message
...
> How much to build the powersupply? I assume we'd be building it. I'd
be
> interested. I love reading the DIY also. Still want to piece
together a
> few of Scott Dorsey's passive EQ's. I hope it'd sound pretty awesome
> 220 per channel is a bit of cash. I won't say steep but it is a DIY
> project for almost 2 grand. (If you do 8 channels)
>
> mark me down for interest peaked.
>
> On 2004-11-12 12:48:21 -0800, "Paul Stamler"
> said:
>
> > Hi folks:
> >
> > Let me launch a trial balloon here. Is this a DIY project that
appeals to
> > you?
> >
> > It's a microphone preamp, solid state, transformer in (Jensen),
> > transformerless balanced +4dBu out with a separate -10dBV
unbalanced out. IC
> > based, up to 8 channels in a 2U case, plus separate power pack.
Phantom on
> > all channels, 100Hz rolloff selectable on all channels, otherwise
no EQ.
> > Designed to be comparable to the Sytek in price, performance and
feature
> > set, but with transformer-coupled inputs. All parts obtainable (to
North
> > Americans, at any rate) from Digi-Key and Allied Electronics,
except for the
> > transformers, which come directly from Jensen. On-card regulation.
Like the
> > Sytek, there are some optional choices in what ICs you use.
> >
> > Approximate costs are as follows. These include everything except
the cases,
> > which are up to you. At the moment I'm assuming the PC boards
would cost
> > $25.00 / ea.; that's the biggest unknown in the equation. I can't
really
> > fill that in until I design the boards, and I'm not gonna do that
until I
> > find out whether anybody's interested. (Also, of course, price of
the boards
> > will vary depending on how many I order.) There are options which
will raise
> > the price, and some that will lower it, but this is the basic
design.
> >
> > Each input channel: $220.00
> >
> > Power Supply: $120.00
> >
> > So a 4-channel unit would cost almost exactly $1k, not counting
boxes. An
> > 8-channel would be $1880, ditto. I'd make my slice selling the PC
boards and
> > writing it up for the magazines.
> >
> > Any interest?
> >
> > Peace,
> > Paul
>
>

[normanstrong]

<Garrett Cox> wrote in message
...
> How much to build the powersupply? I assume we'd be building it. I'd
be
> interested. I love reading the DIY also. Still want to piece
together a
> few of Scott Dorsey's passive EQ's. I hope it'd sound pretty awesome
> 220 per channel is a bit of cash. I won't say steep but it is a DIY
> project for almost 2 grand. (If you do 8 channels)
>
> mark me down for interest peaked.
>
> On 2004-11-12 12:48:21 -0800, "Paul Stamler"
> said:
>
> > Hi folks:
> >
> > Let me launch a trial balloon here. Is this a DIY project that
appeals to
> > you?
> >
> > It's a microphone preamp, solid state, transformer in (Jensen),
> > transformerless balanced +4dBu out with a separate -10dBV
unbalanced out. IC
> > based, up to 8 channels in a 2U case, plus separate power pack.
Phantom on
> > all channels, 100Hz rolloff selectable on all channels, otherwise
no EQ.
> > Designed to be comparable to the Sytek in price, performance and
feature
> > set, but with transformer-coupled inputs. All parts obtainable (to
North
> > Americans, at any rate) from Digi-Key and Allied Electronics,
except for the
> > transformers, which come directly from Jensen. On-card regulation.
Like the
> > Sytek, there are some optional choices in what ICs you use.
> >
> > Approximate costs are as follows. These include everything except
the cases,
> > which are up to you. At the moment I'm assuming the PC boards
would cost
> > $25.00 / ea.; that's the biggest unknown in the equation. I can't
really
> > fill that in until I design the boards, and I'm not gonna do that
until I
> > find out whether anybody's interested. (Also, of course, price of
the boards
> > will vary depending on how many I order.) There are options which
will raise
> > the price, and some that will lower it, but this is the basic
design.
> >
> > Each input channel: $220.00
> >
> > Power Supply: $120.00
> >
> > So a 4-channel unit would cost almost exactly $1k, not counting
boxes. An
> > 8-channel would be $1880, ditto. I'd make my slice selling the PC
boards and
> > writing it up for the magazines.
> >
> > Any interest?
> >
> > Peace,
> > Paul
>
>

[normanstrong]

<Garrett Cox> wrote in message
...
> How much to build the powersupply? I assume we'd be building it. I'd
be
> interested. I love reading the DIY also. Still want to piece
together a
> few of Scott Dorsey's passive EQ's. I hope it'd sound pretty awesome
> 220 per channel is a bit of cash. I won't say steep but it is a DIY
> project for almost 2 grand. (If you do 8 channels)
>
> mark me down for interest peaked.

I think the word you're looking for there is 'piqued'.

[normanstrong]

<Garrett Cox> wrote in message
...
> How much to build the powersupply? I assume we'd be building it. I'd
be
> interested. I love reading the DIY also. Still want to piece
together a
> few of Scott Dorsey's passive EQ's. I hope it'd sound pretty awesome
> 220 per channel is a bit of cash. I won't say steep but it is a DIY
> project for almost 2 grand. (If you do 8 channels)
>
> mark me down for interest peaked.

I think the word you're looking for there is 'piqued'.

[Paul Stamler]

"Mike Rivers" > wrote in message
news:znr1100355094k@trad...

> There are a couple of companies that advertise in the trade magazines
> that custom-punched engraved panels but that's still pretty expensive.
> Markertek is one. Hammond makes a nice rack-mount case for
> construction projects. A 2-space one runs between $55 and $90
> depending on depth and venting.

Sescom sells some for about $35. They offer a custom punching service too.

> Power supplies are probably best bought given the difficulty with
> finding suitable transformers. That would be in the $100-150 range for
> bi-polar 15 to 24 volts plus a single 48 volt supply. You'd need a
> chassis or case for those, too.

Not really necessary; in this design I used 48VCT transformers from Allied
Electronics. They carry several brands, including their house brand,
Stancor, Hammond & Parallax. Decent transformers were very hard to find a
few years ago, but they've gotten easier recently. And the commercial
supplies don't take the extra pains to suppress RFI.

Peace,
Paul

[Paul Stamler]

"Mike Rivers" > wrote in message
news:znr1100355094k@trad...

> There are a couple of companies that advertise in the trade magazines
> that custom-punched engraved panels but that's still pretty expensive.
> Markertek is one. Hammond makes a nice rack-mount case for
> construction projects. A 2-space one runs between $55 and $90
> depending on depth and venting.

Sescom sells some for about $35. They offer a custom punching service too.

> Power supplies are probably best bought given the difficulty with
> finding suitable transformers. That would be in the $100-150 range for
> bi-polar 15 to 24 volts plus a single 48 volt supply. You'd need a
> chassis or case for those, too.

Not really necessary; in this design I used 48VCT transformers from Allied
Electronics. They carry several brands, including their house brand,
Stancor, Hammond & Parallax. Decent transformers were very hard to find a
few years ago, but they've gotten easier recently. And the commercial
supplies don't take the extra pains to suppress RFI.

Peace,
Paul

[Paul Stamler]

"Magnus Jans?n" > wrote in message
m...

> First, I want to be able to get ALL parts at once from one place, and
> that must include the chassis. In case you didn't know this, most
> people don't have the tools to drill in metal when it comes to the
> diameters needed for XLR connectors.
> I want to whip out my credit card, order one neat package with
> EVERYTHING in it and sit down a couple of hours every sunday to
> assemble. I don't have the time or inclination to order parts from 4
> different sources, hunt for a suitable chassi, deal with back-orders
> and replacements, pay $30 in shipping for 3 resistors etc.
> I know you guys don't want to turn your kitchen into a stocking room
> for Digi-key parts, but I'm telling you - when I read "You have to
> order this and that from here and there plus machine your own case" I
> simply flip the page. And I'm not alone.

You sure aren't. I'd love to be able to spec something exactly that way. So
far, though, I haven't found *any* dealer that has everything. If I could, I
would specify them that way in a microsecond.

> Second, I don't think anyone is interested in merly "decent" or
> "servicable" projects. I think most readers have too much of that
> already. We want "really good" or even "outstanding".
> To keep price down I think you need to make costly features optional.
> Many people couldn't care less about HP-filtering, phase switches,
> metering and balanced outputs in a preamp for instance.

Very good point. In this design, you can leave out whatever you don't want;
leaving out the high-pass filter will save $5-something per channel (the
price of the switch), leaving out the balanced outputs will save about $16
per channel. By leaving the phantom on all the time (global on/off switching
only), you save another $5-something. So a stripped-down version would cost
about $148 a channel.

> Here are some DIY-projects that I would like to see (and if they have
> already been published, please tell me which issue they are in):
>
> -Parametric EQ for live use. A clean parametric EQ with very narrow
> bands for full-program corrective live use.
>
> -A/D and D/A converter. There is a remarkable black hole in the market
> for stand-alone 2ch converters in the sub $1000 area. I'm sure there
> are economical reasons for this but if a DIY project could fit in
> there it would be wonderful.
>
> -A "Re-amping" capable DI box. In fact, it wouldn't have to be able to
> do normal DI at all.

One I'd like to see, and don't have the requisite knowledge to design, would
be a really good word clock generator for a couple of hundred bucks. Scott,
are you lisening?

Peace,
Paul

[Paul Stamler]

"Magnus Jans?n" > wrote in message
m...

> First, I want to be able to get ALL parts at once from one place, and
> that must include the chassis. In case you didn't know this, most
> people don't have the tools to drill in metal when it comes to the
> diameters needed for XLR connectors.
> I want to whip out my credit card, order one neat package with
> EVERYTHING in it and sit down a couple of hours every sunday to
> assemble. I don't have the time or inclination to order parts from 4
> different sources, hunt for a suitable chassi, deal with back-orders
> and replacements, pay $30 in shipping for 3 resistors etc.
> I know you guys don't want to turn your kitchen into a stocking room
> for Digi-key parts, but I'm telling you - when I read "You have to
> order this and that from here and there plus machine your own case" I
> simply flip the page. And I'm not alone.

You sure aren't. I'd love to be able to spec something exactly that way. So
far, though, I haven't found *any* dealer that has everything. If I could, I
would specify them that way in a microsecond.

> Second, I don't think anyone is interested in merly "decent" or
> "servicable" projects. I think most readers have too much of that
> already. We want "really good" or even "outstanding".
> To keep price down I think you need to make costly features optional.
> Many people couldn't care less about HP-filtering, phase switches,
> metering and balanced outputs in a preamp for instance.

Very good point. In this design, you can leave out whatever you don't want;
leaving out the high-pass filter will save $5-something per channel (the
price of the switch), leaving out the balanced outputs will save about $16
per channel. By leaving the phantom on all the time (global on/off switching
only), you save another $5-something. So a stripped-down version would cost
about $148 a channel.

> Here are some DIY-projects that I would like to see (and if they have
> already been published, please tell me which issue they are in):
>
> -Parametric EQ for live use. A clean parametric EQ with very narrow
> bands for full-program corrective live use.
>
> -A/D and D/A converter. There is a remarkable black hole in the market
> for stand-alone 2ch converters in the sub $1000 area. I'm sure there
> are economical reasons for this but if a DIY project could fit in
> there it would be wonderful.
>
> -A "Re-amping" capable DI box. In fact, it wouldn't have to be able to
> do normal DI at all.

One I'd like to see, and don't have the requisite knowledge to design, would
be a really good word clock generator for a couple of hundred bucks. Scott,
are you lisening?

Peace,
Paul

[Paul Stamler]

"Jedd Haas" > wrote in message
...

> > Second, I don't think anyone is interested in merly "decent" or
> > "servicable" projects. I think most readers have too much of that
> > already. We want "really good" or even "outstanding".
>
> This comment hits at the key (potential) problem I see with this project.
> Conceptually, it seems similar to the Seventh Circle and Hamptone kits.
> The difference seems to be that you are suggesting "comparable to Sytek"
> performance. I haven't used the Sytek, but most commenters here suggest
> it's "mid-range" in quality. The Seventh Circle preamps aim for "Neve" and
> "API" quality, which is clearly a step up. Those guys also offer complete
> kits with all the parts, including chassis.
>
> These comments are not meant to dog your idea, just pointing out what's
> available and (somewhat) comparable to your idea. It seems to me that,
> while the other guys do have a higher cost per channel, they are offering
> complete kits and (alleged) higher quality. For myself, given the only
> moderate cost differences between your suggested kit and the others, I
> would probably buy the Hamptone or Seventh Circle kits; if I'm going to
> take the time to build it, I want something as good as (or
> better/different) than what I have now (API).

The Hamptone is in a different category; it's a "color" preamp rather than
an attempt at a neutral preamp. This, like the Sytek, aims for neutral. I
haven't checked out the Seventh Circle units.

This project doesn't aim at the stars. If you want the stars in a neutral
sort of way, I say buy a rack full of Great River preamps. They're
superb-sounding, and you get a warranty from a well-established company.
This project has a different ambition; I'd put the quality one notch below
Great River (which is still damned good -- I've made some very nice
recordings using this circuit). The tradeoff is convenience (2RU for 8
channels rather than 8) and cost. Like I say, it's a niche.

> Hamptone and 7C also seem to offer pretty good tech support; are you
> looking to do this as an ongoing business where the sales volume is strong
> enough to provide comparable support? If not, the other alternative might
> be to offer a "PC board only" kit, or a kit with the board and a few
> critical parts.

One of the latter options. I'd sell, I think, PC boards and matched
resistors for the phantom power. And I'd provide lots of hand-holding to
anyone with problems; I just spent several months online debugging one of
the older designs with a guy who built it and had problems. Eventually I had
him ship it to me, and it spent a lot of time on my bench. (That was how I
found out the newer batches of 5534s aren't as stable in regulators.) I'd do
that for anyone who bought a PC board from me, for sure.

Peace,
Paul

[Paul Stamler]

"Jedd Haas" > wrote in message
...

> > Second, I don't think anyone is interested in merly "decent" or
> > "servicable" projects. I think most readers have too much of that
> > already. We want "really good" or even "outstanding".
>
> This comment hits at the key (potential) problem I see with this project.
> Conceptually, it seems similar to the Seventh Circle and Hamptone kits.
> The difference seems to be that you are suggesting "comparable to Sytek"
> performance. I haven't used the Sytek, but most commenters here suggest
> it's "mid-range" in quality. The Seventh Circle preamps aim for "Neve" and
> "API" quality, which is clearly a step up. Those guys also offer complete
> kits with all the parts, including chassis.
>
> These comments are not meant to dog your idea, just pointing out what's
> available and (somewhat) comparable to your idea. It seems to me that,
> while the other guys do have a higher cost per channel, they are offering
> complete kits and (alleged) higher quality. For myself, given the only
> moderate cost differences between your suggested kit and the others, I
> would probably buy the Hamptone or Seventh Circle kits; if I'm going to
> take the time to build it, I want something as good as (or
> better/different) than what I have now (API).

The Hamptone is in a different category; it's a "color" preamp rather than
an attempt at a neutral preamp. This, like the Sytek, aims for neutral. I
haven't checked out the Seventh Circle units.

This project doesn't aim at the stars. If you want the stars in a neutral
sort of way, I say buy a rack full of Great River preamps. They're
superb-sounding, and you get a warranty from a well-established company.
This project has a different ambition; I'd put the quality one notch below
Great River (which is still damned good -- I've made some very nice
recordings using this circuit). The tradeoff is convenience (2RU for 8
channels rather than 8) and cost. Like I say, it's a niche.

> Hamptone and 7C also seem to offer pretty good tech support; are you
> looking to do this as an ongoing business where the sales volume is strong
> enough to provide comparable support? If not, the other alternative might
> be to offer a "PC board only" kit, or a kit with the board and a few
> critical parts.

One of the latter options. I'd sell, I think, PC boards and matched
resistors for the phantom power. And I'd provide lots of hand-holding to
anyone with problems; I just spent several months online debugging one of
the older designs with a guy who built it and had problems. Eventually I had
him ship it to me, and it spent a lot of time on my bench. (That was how I
found out the newer batches of 5534s aren't as stable in regulators.) I'd do
that for anyone who bought a PC board from me, for sure.

Peace,
Paul

[hank alrich]

<Garrett> wrote:

> You could probably find a suitable Bud box for it. I do agree the
> pricing is something to consider still.

> On 2004-11-12 17:37:14 -0800, (Mike Rivers) said:
> > I think that the average DIYer today would find that to be too much
> > cash to put into a project, particularly since it involves a case and
> > considerable metalworking skill to make a unit that looks decent. You
> > might sell about ten, and you know what Recording pays for articles.
> > <g>

I think people think they want to build a great preamp project that
costs less in total per channel than the price of a jensen input
transformer. <g>

--
ha

[hank alrich]

<Garrett> wrote:

> You could probably find a suitable Bud box for it. I do agree the
> pricing is something to consider still.

> On 2004-11-12 17:37:14 -0800, (Mike Rivers) said:
> > I think that the average DIYer today would find that to be too much
> > cash to put into a project, particularly since it involves a case and
> > considerable metalworking skill to make a unit that looks decent. You
> > might sell about ten, and you know what Recording pays for articles.
> > <g>

I think people think they want to build a great preamp project that
costs less in total per channel than the price of a jensen input
transformer. <g>

--
ha

[Hal Laurent]

"agent86" > wrote in message
.. .
>
> What's street on the 8 channel Presonus these days? The Full Compass
> catalog copy says "Jensen", but IIRC, they had switched to a cheaper
> transformer sometime back.

I assume you mean the M80, since the other Presonus 8-channel units don't
have transformers. The M80 can be had new for around $1400.

Hal Laurent
Baltimore

[Hal Laurent]

"agent86" > wrote in message
.. .
>
> What's street on the 8 channel Presonus these days? The Full Compass
> catalog copy says "Jensen", but IIRC, they had switched to a cheaper
> transformer sometime back.

I assume you mean the M80, since the other Presonus 8-channel units don't
have transformers. The M80 can be had new for around $1400.

Hal Laurent
Baltimore

[Hal Laurent]

"Paul Stamler" > wrote in message
...

> This project doesn't aim at the stars. If you want the stars in a neutral
> sort of way, I say buy a rack full of Great River preamps. They're
> superb-sounding, and you get a warranty from a well-established company.
> This project has a different ambition; I'd put the quality one notch below
> Great River (which is still damned good -- I've made some very nice
> recordings using this circuit). The tradeoff is convenience (2RU for 8
> channels rather than 8) and cost. Like I say, it's a niche.

You don't need 8RU for 8 channels of Great River (or Hardy). A pair
of the four-channel versions of either will fit in 2RU. As will 8 channels
of Sytek.

Hal Laurent
Baltimore

[Hal Laurent]

"Paul Stamler" > wrote in message
...

> This project doesn't aim at the stars. If you want the stars in a neutral
> sort of way, I say buy a rack full of Great River preamps. They're
> superb-sounding, and you get a warranty from a well-established company.
> This project has a different ambition; I'd put the quality one notch below
> Great River (which is still damned good -- I've made some very nice
> recordings using this circuit). The tradeoff is convenience (2RU for 8
> channels rather than 8) and cost. Like I say, it's a niche.

You don't need 8RU for 8 channels of Great River (or Hardy). A pair
of the four-channel versions of either will fit in 2RU. As will 8 channels
of Sytek.

Hal Laurent
Baltimore

[agent86]

Paul Stamler wrote:

> Revised cost estimate:
>
> 2 ch.: $490
> 4 ch.: $840
> 8 ch.: $1540
>
> The idea is to provide up to 8 channels of preamp in a 2U box (plus the
> outboard power supply). 8 in a box for compactness, particularly for
> people doing remote work, or for folks who just want 8 identical
> good-quality preamps. It seems to be a pretty popular format at several
> price points; the one thing I notice, though, is that none of the
> 8-bangers out there are transformer-coupled, and some of us like
> transformers, for (as I mentioned) RFI-proofing, loading, whatever. So I'm
> looking to see whether there's a niche here. There wouldn't be, I don't
> think, for a manufactured version of this; the price would be prohibitive.
> But perhaps as a DIY it might slip in. So I'm running it up the flagpole.

What's street on the 8 channel Presonus these days? The Full Compass
catalog copy says "Jensen", but IIRC, they had switched to a cheaper
transformer sometime back.

I'm one of those who likes transformers too. But I've come to the
conclusion that the most cost effective avenue (for me) is to save up for a
GR or a Hardy (since I am determined to get one eventually anyway).
Obviously, everybody's situation is different. But I kind of think most
people would sooner buy a complete functional unit than build it IF what
they need is available at anywhere close to the same cost.

But good luck with it anyway.

[agent86]

Paul Stamler wrote:

> Revised cost estimate:
>
> 2 ch.: $490
> 4 ch.: $840
> 8 ch.: $1540
>
> The idea is to provide up to 8 channels of preamp in a 2U box (plus the
> outboard power supply). 8 in a box for compactness, particularly for
> people doing remote work, or for folks who just want 8 identical
> good-quality preamps. It seems to be a pretty popular format at several
> price points; the one thing I notice, though, is that none of the
> 8-bangers out there are transformer-coupled, and some of us like
> transformers, for (as I mentioned) RFI-proofing, loading, whatever. So I'm
> looking to see whether there's a niche here. There wouldn't be, I don't
> think, for a manufactured version of this; the price would be prohibitive.
> But perhaps as a DIY it might slip in. So I'm running it up the flagpole.

What's street on the 8 channel Presonus these days? The Full Compass
catalog copy says "Jensen", but IIRC, they had switched to a cheaper
transformer sometime back.

I'm one of those who likes transformers too. But I've come to the
conclusion that the most cost effective avenue (for me) is to save up for a
GR or a Hardy (since I am determined to get one eventually anyway).
Obviously, everybody's situation is different. But I kind of think most
people would sooner buy a complete functional unit than build it IF what
they need is available at anywhere close to the same cost.

But good luck with it anyway.

[james of tucson]

On 2004-11-13, Mike Rivers > wrote:

> If you're going to build something that costs $2,000 or more, you want
> to put it in a box that makes it look like $2,000, with all the round
> holes round, and lined up straight. And you probably want engraved or
> silkscreened legends rather than strips of label tape.

A nice front panel is easy! You don't have to have a CNC mill yourself,
and you don't have to struggle with the dremel. Check out Front Panel
Express, or Schaeffer AG. The cost depends on the complexity of your
panel, but it is quite reasonable, and cheap enough to be used on
countless low budget DIY synth projects that I've seen.

[james of tucson]

On 2004-11-13, Mike Rivers > wrote:

> If you're going to build something that costs $2,000 or more, you want
> to put it in a box that makes it look like $2,000, with all the round
> holes round, and lined up straight. And you probably want engraved or
> silkscreened legends rather than strips of label tape.

A nice front panel is easy! You don't have to have a CNC mill yourself,
and you don't have to struggle with the dremel. Check out Front Panel
Express, or Schaeffer AG. The cost depends on the complexity of your
panel, but it is quite reasonable, and cheap enough to be used on
countless low budget DIY synth projects that I've seen.

[Garrett]

Personally, I wouldn't mind what it looked like as long as it sounded
good and the 1500 or 1800 I spent was justified. I think the purpose
for me would be just usability. No bling or whatever.

cheers

garrett


On 2004-11-13 08:11:13 -0800, (Mike Rivers) said:
>>
>
> If you're going to build something that costs $2,000 or more, you want
> to put it in a box that makes it look like $2,000, with all the round
> holes round, and lined up straight. And you probably want engraved or
> silkscreened legends rather than strips of label tape. One of the
> things about undertaking a DIY project (and our furniture-building
> friends will surely agree) is not just to make something cheap or to
> make something that you can't buy easily, but to make something that
> you're proud of - whether it's a mic preamp, a custom cable, or a set
> of shelves to store your backups.
>
> There are a couple of companies that advertise in the trade magazines
> that custom-punched engraved panels but that's still pretty expensive.
> Markertek is one. Hammond makes a nice rack-mount case for
> construction projects. A 2-space one runs between $55 and $90
> depending on depth and venting.
>
> Power supplies are probably best bought given the difficulty with
> finding suitable transformers. That would be in the $100-150 range for
> bi-polar 15 to 24 volts plus a single 48 volt supply. You'd need a
> chassis or case for those, too.

[Garrett]

Personally, I wouldn't mind what it looked like as long as it sounded
good and the 1500 or 1800 I spent was justified. I think the purpose
for me would be just usability. No bling or whatever.

cheers

garrett


On 2004-11-13 08:11:13 -0800, (Mike Rivers) said:
>>
>
> If you're going to build something that costs $2,000 or more, you want
> to put it in a box that makes it look like $2,000, with all the round
> holes round, and lined up straight. And you probably want engraved or
> silkscreened legends rather than strips of label tape. One of the
> things about undertaking a DIY project (and our furniture-building
> friends will surely agree) is not just to make something cheap or to
> make something that you can't buy easily, but to make something that
> you're proud of - whether it's a mic preamp, a custom cable, or a set
> of shelves to store your backups.
>
> There are a couple of companies that advertise in the trade magazines
> that custom-punched engraved panels but that's still pretty expensive.
> Markertek is one. Hammond makes a nice rack-mount case for
> construction projects. A 2-space one runs between $55 and $90
> depending on depth and venting.
>
> Power supplies are probably best bought given the difficulty with
> finding suitable transformers. That would be in the $100-150 range for
> bi-polar 15 to 24 volts plus a single 48 volt supply. You'd need a
> chassis or case for those, too.

[Scott Dorsey]

Paul Stamler > wrote:
>
>You sure aren't. I'd love to be able to spec something exactly that way. So
>far, though, I haven't found *any* dealer that has everything. If I could, I
>would specify them that way in a microsecond.

I try very hard to build projects so as much as possible can be ordered
from one supplier, almost always Digi-Key. Sometimes this means reducing
some aspect of performance by replacing a difficult part with one that
Digi-Key has stocked.

The Chinese mike modification article sat on the shelf for about three years
before getting published, because I couldn't find a decent supplier for high
value resistors in small quantities. As soon as Digi-Key picked up the
Ohmite line, the article went into print.

The long-awaited tube mike preamp article that I promised Nick Batzdorf
back when he was editing Recording has still not come out yet, and finding
a single parts source is half of the problem there. I have it down to six
suppliers but that's way too many.

>One I'd like to see, and don't have the requisite knowledge to design, would
>be a really good word clock generator for a couple of hundred bucks. Scott,
>are you lisening?

I don't have any way of measuring how accurate a clock is any longer. They
shut down some of the labs at my day job and I no longer have the Tek
modulation domain analyzer to play with. This makes it very difficult to
build a reference clock and really assure yourself that it's any good.
I can build a clock, sure. But will it be an improvement? I have no way of
telling.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Paul Stamler > wrote:
>
>You sure aren't. I'd love to be able to spec something exactly that way. So
>far, though, I haven't found *any* dealer that has everything. If I could, I
>would specify them that way in a microsecond.

I try very hard to build projects so as much as possible can be ordered
from one supplier, almost always Digi-Key. Sometimes this means reducing
some aspect of performance by replacing a difficult part with one that
Digi-Key has stocked.

The Chinese mike modification article sat on the shelf for about three years
before getting published, because I couldn't find a decent supplier for high
value resistors in small quantities. As soon as Digi-Key picked up the
Ohmite line, the article went into print.

The long-awaited tube mike preamp article that I promised Nick Batzdorf
back when he was editing Recording has still not come out yet, and finding
a single parts source is half of the problem there. I have it down to six
suppliers but that's way too many.

>One I'd like to see, and don't have the requisite knowledge to design, would
>be a really good word clock generator for a couple of hundred bucks. Scott,
>are you lisening?

I don't have any way of measuring how accurate a clock is any longer. They
shut down some of the labs at my day job and I no longer have the Tek
modulation domain analyzer to play with. This makes it very difficult to
build a reference clock and really assure yourself that it's any good.
I can build a clock, sure. But will it be an improvement? I have no way of
telling.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Mark]

....

and I'd make sure the design was RFI proof for the input and output as
well as the power supply.

I think RFI suseptability is one of the biggest weakness of commercial
gear.

If you create a bullet proof design RFI wse, it would have appeal.

That means ground the XLR connector shield pin and shell DIRECTLY to
the metal chassis for starters.


Mark

[Mark]

....

and I'd make sure the design was RFI proof for the input and output as
well as the power supply.

I think RFI suseptability is one of the biggest weakness of commercial
gear.

If you create a bullet proof design RFI wse, it would have appeal.

That means ground the XLR connector shield pin and shell DIRECTLY to
the metal chassis for starters.


Mark

[Pooh Bear]

Mark wrote:

> ...
>
> and I'd make sure the design was RFI proof for the input and output as
> well as the power supply.
>
> I think RFI suseptability is one of the biggest weakness of commercial
> gear.
>
> If you create a bullet proof design RFI wse, it would have appeal.
>
> That means ground the XLR connector shield pin and shell DIRECTLY to
> the metal chassis for starters.

Does anyone *not* do that these days ?

Just asking. Been there done that - had the EMI course ( as part of his
consultancy ) over the years from a wonderful Hungarian ? expert.

He thinks the EMI regs are bonkers ( as in totally over the top ) btw !


Graham

[Pooh Bear]

Mark wrote:

> ...
>
> and I'd make sure the design was RFI proof for the input and output as
> well as the power supply.
>
> I think RFI suseptability is one of the biggest weakness of commercial
> gear.
>
> If you create a bullet proof design RFI wse, it would have appeal.
>
> That means ground the XLR connector shield pin and shell DIRECTLY to
> the metal chassis for starters.

Does anyone *not* do that these days ?

Just asking. Been there done that - had the EMI course ( as part of his
consultancy ) over the years from a wonderful Hungarian ? expert.

He thinks the EMI regs are bonkers ( as in totally over the top ) btw !


Graham

[Bob Cain]

normanstrong wrote:

> If you want
> to design something useful, come up with a battery operated unit at
> $50/channel.

My sentiment as well. No rolloff necessasary, 60 dB gain,
-130 dBu A weighted Ein noise, phantom power.

What I'm dying for is a four channel as per above but with a
form of gain control that will allow any number of channels
to be ganged and operated with a single control. Some kind
precision voltage controled pot on each channel if such a
thing exists.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

[Bob Cain]

normanstrong wrote:

> If you want
> to design something useful, come up with a battery operated unit at
> $50/channel.

My sentiment as well. No rolloff necessasary, 60 dB gain,
-130 dBu A weighted Ein noise, phantom power.

What I'm dying for is a four channel as per above but with a
form of gain control that will allow any number of channels
to be ganged and operated with a single control. Some kind
precision voltage controled pot on each channel if such a
thing exists.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

[Frank Vuotto]

On 13 Nov 2004 17:06:49 -0500, (Scott Dorsey) wrote:

>
>The long-awaited tube mike preamp article that I promised Nick Batzdorf
>back when he was editing Recording has still not come out yet, and finding
>a single parts source is half of the problem there. I have it down to six
>suppliers but that's way too many.

Would that be the transformerless input :-)


Frank /~ http://newmex.com/f10
@/

[Frank Vuotto]

On 13 Nov 2004 17:06:49 -0500, (Scott Dorsey) wrote:

>
>The long-awaited tube mike preamp article that I promised Nick Batzdorf
>back when he was editing Recording has still not come out yet, and finding
>a single parts source is half of the problem there. I have it down to six
>suppliers but that's way too many.

Would that be the transformerless input :-)


Frank /~ http://newmex.com/f10
@/

[Mike Rivers]

In article > writes:

> I have some general opinions on magazine-published DIY projects, and
> this is aimed not only at Mr Stamler but also Mr Dorsey and everyone
> else that do these things.
>
> First, I want to be able to get ALL parts at once from one place, and
> that must include the chassis.

That's really nice, but unless someone is willing to put together a
complete kit, it really can't be done. Paia used to do this but they
don't seem to be quite so active in that area these days. Understand
that this requires a substantial investment when it comes to
metalwork. They can often use resistors, capacitors and op amp chips
for multiple products but they can't punch a chassis for an 8-channel
mic preamp and use it for a compressor.

> In case you didn't know this, most
> people don't have the tools to drill in metal when it comes to the
> diameters needed for XLR connectors.

Actually that isn't too difficult. If you're going to build a $2,000
preamp, you're probably into building things and you don't have to
start out by buying every tool that you need, because you already have
a decent shop. A good start for audio projects is a set of Greenlee
chassis punches for male and female XLR connectors, about $40 a piece.
I'll admit that this can make a single channel project a bit
expensive, but DIY projects are addictive. If you do one, you'll
probably do several.

But I understand completely where you're coming from. When I was in
high school I worked summers and Saturdays in the tool crib of a
machine shop and I built some lovely ham radio gear because I had
access to brakes and punches for making the chassis. It made a big
difference in projects that I started over having to use a ready-made
chassis that was too big, too small, too deep, or too shallow, and had
to make holes for tube sockets by drilling a bunch of holes around the
circumference of a circle and filing out the scrap. Today I have a
drill press but no brake, so I don't do as much DIY as I used to.

> I want to whip out my credit card, order one neat package with
> EVERYTHING in it and sit down a couple of hours every sunday to
> assemble.

Too bad you're too young to have ever built a Heathkit. But they went
out of business because eventually it wasn't cost effective to put
together and document a kit. You could buy the equivalent a whole lot
cheaper. A technician who used to work with me built a Heathkit color
TV and a Heathkit microwave oven, and had Heathkit oscilloscopes and
signal generators in his home TV service shop. In 1965 you could save
money by building the kit, but today you can buy better commercial
products for a fraction of the cost of the Heathkits, even in 1965
dollars.

> Second, I don't think anyone is interested in merly "decent" or
> "servicable" projects. I think most readers have too much of that
> already. We want "really good" or even "outstanding".

This is why I didn't think Paul's project would be a smashing success.
On the other hand, a project like Scott's Oktava mic modifications
that involve a simple circuit board that he can provide, a handful of
parts, and only small hand tools are pretty popular.

> To keep price down I think you need to make costly features optional.
> Many people couldn't care less about HP-filtering, phase switches,
> metering and balanced outputs in a preamp for instance.

I wrote an article in Recording a while back about developing your own
DIY project (using a monitor switcher as an example) in which I
explained exactly that concept - but the point of my article was that
YOU could make those decisions. It's not difficult to find application
notes for transfomrers and op amps that will get you a decent mic
preamp and you can make it "really good" or even "outstanding" by the
way you apply what's in those application notes. If you want someone
to make those decisions for you, you have to accept his take on what's
good for you.

> Here are some DIY-projects that I would like to see (and if they have
> already been published, please tell me which issue they are in):
>
> -Parametric EQ for live use. A clean parametric EQ with very narrow
> bands for full-program corrective live use.

Paia had a kit for one many years ago, and it's probalby still in
their catalog. I built one and I still use it occasionally.

> -A/D and D/A converter. There is a remarkable black hole in the market
> for stand-alone 2ch converters in the sub $1000 area. I'm sure there
> are economical reasons for this but if a DIY project could fit in
> there it would be wonderful.

This is one of those areas (like mic preamps - see John La Grou's
recent postings on the subject) where "art" comes into play. Again,
there are application notes for perfectly good A/D and D/A chips that
will get you the functions with reasonably good performance. But in
order to make it really great, you need a nice clean power supply, a
low jitter clock source, and good analog circuitry around the chip.
That's about four application notes. If you want someone to combine
those, experiment with optimizing components and circuit board layout,
finding sources for all the parts, and punching a chassis, who's going
to pay for it?

> -A "Re-amping" capable DI box. In fact, it wouldn't have to be able to
> do normal DI at all.

This is a perfectly good example of a project that you could develop
yourself. All you need to do is understand what you need to
accomplish. Package it as pretty or as ugly as you wish.


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> I have some general opinions on magazine-published DIY projects, and
> this is aimed not only at Mr Stamler but also Mr Dorsey and everyone
> else that do these things.
>
> First, I want to be able to get ALL parts at once from one place, and
> that must include the chassis.

That's really nice, but unless someone is willing to put together a
complete kit, it really can't be done. Paia used to do this but they
don't seem to be quite so active in that area these days. Understand
that this requires a substantial investment when it comes to
metalwork. They can often use resistors, capacitors and op amp chips
for multiple products but they can't punch a chassis for an 8-channel
mic preamp and use it for a compressor.

> In case you didn't know this, most
> people don't have the tools to drill in metal when it comes to the
> diameters needed for XLR connectors.

Actually that isn't too difficult. If you're going to build a $2,000
preamp, you're probably into building things and you don't have to
start out by buying every tool that you need, because you already have
a decent shop. A good start for audio projects is a set of Greenlee
chassis punches for male and female XLR connectors, about $40 a piece.
I'll admit that this can make a single channel project a bit
expensive, but DIY projects are addictive. If you do one, you'll
probably do several.

But I understand completely where you're coming from. When I was in
high school I worked summers and Saturdays in the tool crib of a
machine shop and I built some lovely ham radio gear because I had
access to brakes and punches for making the chassis. It made a big
difference in projects that I started over having to use a ready-made
chassis that was too big, too small, too deep, or too shallow, and had
to make holes for tube sockets by drilling a bunch of holes around the
circumference of a circle and filing out the scrap. Today I have a
drill press but no brake, so I don't do as much DIY as I used to.

> I want to whip out my credit card, order one neat package with
> EVERYTHING in it and sit down a couple of hours every sunday to
> assemble.

Too bad you're too young to have ever built a Heathkit. But they went
out of business because eventually it wasn't cost effective to put
together and document a kit. You could buy the equivalent a whole lot
cheaper. A technician who used to work with me built a Heathkit color
TV and a Heathkit microwave oven, and had Heathkit oscilloscopes and
signal generators in his home TV service shop. In 1965 you could save
money by building the kit, but today you can buy better commercial
products for a fraction of the cost of the Heathkits, even in 1965
dollars.

> Second, I don't think anyone is interested in merly "decent" or
> "servicable" projects. I think most readers have too much of that
> already. We want "really good" or even "outstanding".

This is why I didn't think Paul's project would be a smashing success.
On the other hand, a project like Scott's Oktava mic modifications
that involve a simple circuit board that he can provide, a handful of
parts, and only small hand tools are pretty popular.

> To keep price down I think you need to make costly features optional.
> Many people couldn't care less about HP-filtering, phase switches,
> metering and balanced outputs in a preamp for instance.

I wrote an article in Recording a while back about developing your own
DIY project (using a monitor switcher as an example) in which I
explained exactly that concept - but the point of my article was that
YOU could make those decisions. It's not difficult to find application
notes for transfomrers and op amps that will get you a decent mic
preamp and you can make it "really good" or even "outstanding" by the
way you apply what's in those application notes. If you want someone
to make those decisions for you, you have to accept his take on what's
good for you.

> Here are some DIY-projects that I would like to see (and if they have
> already been published, please tell me which issue they are in):
>
> -Parametric EQ for live use. A clean parametric EQ with very narrow
> bands for full-program corrective live use.

Paia had a kit for one many years ago, and it's probalby still in
their catalog. I built one and I still use it occasionally.

> -A/D and D/A converter. There is a remarkable black hole in the market
> for stand-alone 2ch converters in the sub $1000 area. I'm sure there
> are economical reasons for this but if a DIY project could fit in
> there it would be wonderful.

This is one of those areas (like mic preamps - see John La Grou's
recent postings on the subject) where "art" comes into play. Again,
there are application notes for perfectly good A/D and D/A chips that
will get you the functions with reasonably good performance. But in
order to make it really great, you need a nice clean power supply, a
low jitter clock source, and good analog circuitry around the chip.
That's about four application notes. If you want someone to combine
those, experiment with optimizing components and circuit board layout,
finding sources for all the parts, and punching a chassis, who's going
to pay for it?

> -A "Re-amping" capable DI box. In fact, it wouldn't have to be able to
> do normal DI at all.

This is a perfectly good example of a project that you could develop
yourself. All you need to do is understand what you need to
accomplish. Package it as pretty or as ugly as you wish.


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Scott Dorsey]

Mark > wrote:
>
>and I'd make sure the design was RFI proof for the input and output as
>well as the power supply.

With an input transformer, that's easy to do. High CMRR and low-pass
filtering are free in the bargain.

>I think RFI suseptability is one of the biggest weakness of commercial
>gear.

That's because people are willing to put up with bad design. It's not just
that transformers are expensive; just looking at the number of internal
ground loops on some commercial boxes out there is amazing.

>If you create a bullet proof design RFI wse, it would have appeal.
>
>That means ground the XLR connector shield pin and shell DIRECTLY to
>the metal chassis for starters.

Not necessarily. Check out Deane Jensen's recent papers on the "Pin 1
Problem."
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Mark > wrote:
>
>and I'd make sure the design was RFI proof for the input and output as
>well as the power supply.

With an input transformer, that's easy to do. High CMRR and low-pass
filtering are free in the bargain.

>I think RFI suseptability is one of the biggest weakness of commercial
>gear.

That's because people are willing to put up with bad design. It's not just
that transformers are expensive; just looking at the number of internal
ground loops on some commercial boxes out there is amazing.

>If you create a bullet proof design RFI wse, it would have appeal.
>
>That means ground the XLR connector shield pin and shell DIRECTLY to
>the metal chassis for starters.

Not necessarily. Check out Deane Jensen's recent papers on the "Pin 1
Problem."
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Frank Vuotto > wrote:
>On 13 Nov 2004 17:06:49 -0500, (Scott Dorsey) wrote:
>
>>The long-awaited tube mike preamp article that I promised Nick Batzdorf
>>back when he was editing Recording has still not come out yet, and finding
>>a single parts source is half of the problem there. I have it down to six
>>suppliers but that's way too many.
>
>Would that be the transformerless input :-)

Not at the price point Recording wants for DIY projects. If I could do a
transformerless one for cheap, that would eliminate one of the six suppliers
(which is Lundahl). I played around a little bit with a transformerless
grounded-grid design with a bunch of paralleled tubes, and it sounded good,
but it required a lot of trimming and selected tubes in order to get it
quiet and with low distortion. Actually winds up costing _more_ than a
transformer input, what with all the more expensive input tubes and the
trimpots.

About half of the cost of the preamp actually is in the power supply, and I
worked very hard to try and bring the power supply parts cost down and try
and do it entirely with Digi-Key parts. I was not able to do so. Everything
I did to cut corners in the supply wound up affecting the sound too much.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Frank Vuotto > wrote:
>On 13 Nov 2004 17:06:49 -0500, (Scott Dorsey) wrote:
>
>>The long-awaited tube mike preamp article that I promised Nick Batzdorf
>>back when he was editing Recording has still not come out yet, and finding
>>a single parts source is half of the problem there. I have it down to six
>>suppliers but that's way too many.
>
>Would that be the transformerless input :-)

Not at the price point Recording wants for DIY projects. If I could do a
transformerless one for cheap, that would eliminate one of the six suppliers
(which is Lundahl). I played around a little bit with a transformerless
grounded-grid design with a bunch of paralleled tubes, and it sounded good,
but it required a lot of trimming and selected tubes in order to get it
quiet and with low distortion. Actually winds up costing _more_ than a
transformer input, what with all the more expensive input tubes and the
trimpots.

About half of the cost of the preamp actually is in the power supply, and I
worked very hard to try and bring the power supply parts cost down and try
and do it entirely with Digi-Key parts. I was not able to do so. Everything
I did to cut corners in the supply wound up affecting the sound too much.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Kurt Albershardt]

Mike Rivers wrote:
> In article > writes:
>
>> In case you didn't know this, most
>> people don't have the tools to drill in metal when it comes to
>> the diameters needed for XLR connectors.
>
>
> Actually that isn't too difficult. If you're going to build a $2,000
> preamp, you're probably into building things and you don't have to
> start out by buying every tool that you need, because you already have
> a decent shop. A good start for audio projects is a set of Greenlee
> chassis punches for male and female XLR connectors, about $40 a piece.

I thought these punches were more like $200-250 each? You are talking about the ones with the slots for the mounting screws, right?

[Kurt Albershardt]

Mike Rivers wrote:
> In article > writes:
>
>> In case you didn't know this, most
>> people don't have the tools to drill in metal when it comes to
>> the diameters needed for XLR connectors.
>
>
> Actually that isn't too difficult. If you're going to build a $2,000
> preamp, you're probably into building things and you don't have to
> start out by buying every tool that you need, because you already have
> a decent shop. A good start for audio projects is a set of Greenlee
> chassis punches for male and female XLR connectors, about $40 a piece.

I thought these punches were more like $200-250 each? You are talking about the ones with the slots for the mounting screws, right?

[Geoff Wood]

"Paul Stamler" > wrote in message news:pk9ld.891630

> Approximate costs are as follows. These include everything except the
> cases,
> which are up to you. At the moment I'm assuming the PC boards would cost
> $25.00 / ea.;


Good so far ....

that's the biggest unknown in the equation. I can't really
> fill that in until I design the boards, and I'm not gonna do that until I
> find out whether anybody's interested. (Also, of course, price of the
> boards
> will vary depending on how many I order.) There are options which will
> raise
> the price, and some that will lower it, but this is the basic design.
>
> Each input channel: $220.00

What is in it that bumps up the cost this much ? Maybe transformer, stepped
swtich, platinum op-amps ?


> Power Supply: $120.00

I'm so would supply own transformer....

> Any interest?

Yep, in the cct board !


geoff

[Geoff Wood]

"Paul Stamler" > wrote in message news:pk9ld.891630

> Approximate costs are as follows. These include everything except the
> cases,
> which are up to you. At the moment I'm assuming the PC boards would cost
> $25.00 / ea.;


Good so far ....

that's the biggest unknown in the equation. I can't really
> fill that in until I design the boards, and I'm not gonna do that until I
> find out whether anybody's interested. (Also, of course, price of the
> boards
> will vary depending on how many I order.) There are options which will
> raise
> the price, and some that will lower it, but this is the basic design.
>
> Each input channel: $220.00

What is in it that bumps up the cost this much ? Maybe transformer, stepped
swtich, platinum op-amps ?


> Power Supply: $120.00

I'm so would supply own transformer....

> Any interest?

Yep, in the cct board !


geoff

[Geoff Wood]

"agent86" > wrote in message
.. .
> Mike Rivers wrote:
>
>> I think that the average DIYer today would find that to be too much
>> cash to put into a project, particularly since it involves a case and
>> considerable metalworking skill to make a unit that looks decent.
>
> Very true. With the RNP going for $475 new, what's the point (unless you
> just absolutely HAVE to have transformers). And why would you reall NEED
> transformers at that price point, since Shure 57s behave themselves pretty
> well with the RNP?


I'd be more interested in variable input impedence.

geoff

[Geoff Wood]

"agent86" > wrote in message
.. .
> Mike Rivers wrote:
>
>> I think that the average DIYer today would find that to be too much
>> cash to put into a project, particularly since it involves a case and
>> considerable metalworking skill to make a unit that looks decent.
>
> Very true. With the RNP going for $475 new, what's the point (unless you
> just absolutely HAVE to have transformers). And why would you reall NEED
> transformers at that price point, since Shure 57s behave themselves pretty
> well with the RNP?


I'd be more interested in variable input impedence.

geoff

[Ben Bradley]

On Fri, 12 Nov 2004 20:48:21 GMT, "Paul Stamler"
> wrote:

>Hi folks:
>
>Let me launch a trial balloon here. Is this a DIY project that appeals to
>you?
>
>It's a microphone preamp, solid state, transformer in (Jensen),

>...

> I'd make my slice selling the PC boards and
>writing it up for the magazines.

Speaking of PC boards, would it be all thru-hole, or any surface
mount? You're of course aware that more and more parts are only
available in SMT thesedays, and some people won't want to solder SMT
parts (even though the .050 pitch pins aren't hard). Or does it depend
on IC options? You could make a dual thru-hole/surface mount layout
for the chips that come in both.
FWIW, I probably won't build it, though I may buy the magazine you
publish it in.

>
>Any interest?
>
>Peace,
>Paul
>

-----
http://mindspring.com/~benbradley

[Ben Bradley]

On Fri, 12 Nov 2004 20:48:21 GMT, "Paul Stamler"
> wrote:

>Hi folks:
>
>Let me launch a trial balloon here. Is this a DIY project that appeals to
>you?
>
>It's a microphone preamp, solid state, transformer in (Jensen),

>...

> I'd make my slice selling the PC boards and
>writing it up for the magazines.

Speaking of PC boards, would it be all thru-hole, or any surface
mount? You're of course aware that more and more parts are only
available in SMT thesedays, and some people won't want to solder SMT
parts (even though the .050 pitch pins aren't hard). Or does it depend
on IC options? You could make a dual thru-hole/surface mount layout
for the chips that come in both.
FWIW, I probably won't build it, though I may buy the magazine you
publish it in.

>
>Any interest?
>
>Peace,
>Paul
>

-----
http://mindspring.com/~benbradley

[Bob Cain]

Geoff Wood wrote:

> I'd be more interested in variable input impedence.

Which reminds me of a question that came up on another
forum. Seems that pre impedences are down in the 2K Ohm and
below range. Have they always been that low and why such a
relatively big load?


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

[Bob Cain]

Geoff Wood wrote:

> I'd be more interested in variable input impedence.

Which reminds me of a question that came up on another
forum. Seems that pre impedences are down in the 2K Ohm and
below range. Have they always been that low and why such a
relatively big load?


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

[Paul Stamler]

"Scott Dorsey" > wrote in message
...

> About half of the cost of the preamp actually is in the power supply, and
I
> worked very hard to try and bring the power supply parts cost down and try
> and do it entirely with Digi-Key parts. I was not able to do so.
Everything
> I did to cut corners in the supply wound up affecting the sound too much.

Scott, try Allied. The new catalog has a surprising number of
tube-compatible power transformers. Combine them with Digi-Key plus a tube
supplier and you may bring the number of suppliers down to three.

Peace,
Paul

[Paul Stamler]

"Scott Dorsey" > wrote in message
...

> About half of the cost of the preamp actually is in the power supply, and
I
> worked very hard to try and bring the power supply parts cost down and try
> and do it entirely with Digi-Key parts. I was not able to do so.
Everything
> I did to cut corners in the supply wound up affecting the sound too much.

Scott, try Allied. The new catalog has a surprising number of
tube-compatible power transformers. Combine them with Digi-Key plus a tube
supplier and you may bring the number of suppliers down to three.

Peace,
Paul

[Paul Stamler]

"Ben Bradley" > wrote in message
...

> > I'd make my slice selling the PC boards and
> >writing it up for the magazines.
>
> Speaking of PC boards, would it be all thru-hole, or any surface
> mount? You're of course aware that more and more parts are only
> available in SMT thesedays, and some people won't want to solder SMT
> parts (even though the .050 pitch pins aren't hard). Or does it depend
> on IC options? You could make a dual thru-hole/surface mount layout
> for the chips that come in both.

Through-hole. I'm too shaky to solder SMT myself.

The ICs are nothing exotic, and available in 8-DIPs.

Peace,
Paul

[Paul Stamler]

"Ben Bradley" > wrote in message
...

> > I'd make my slice selling the PC boards and
> >writing it up for the magazines.
>
> Speaking of PC boards, would it be all thru-hole, or any surface
> mount? You're of course aware that more and more parts are only
> available in SMT thesedays, and some people won't want to solder SMT
> parts (even though the .050 pitch pins aren't hard). Or does it depend
> on IC options? You could make a dual thru-hole/surface mount layout
> for the chips that come in both.

Through-hole. I'm too shaky to solder SMT myself.

The ICs are nothing exotic, and available in 8-DIPs.

Peace,
Paul

[Garrett]

Sorry yes "piqued" Had a few drinks and was in a hurry. Piqued.

cheers

garrett

On 2004-11-13 10:04:50 -0800, "normanstrong" > said:

>
> <Garrett Cox> wrote in message
> ...
>> How much to build the powersupply? I assume we'd be building it. I'd
> be
>> interested. I love reading the DIY also. Still want to piece
> together a
>> few of Scott Dorsey's passive EQ's. I hope it'd sound pretty awesome
>> 220 per channel is a bit of cash. I won't say steep but it is a DIY
>> project for almost 2 grand. (If you do 8 channels)
>>
>> mark me down for interest peaked.
>
> I think the word you're looking for there is 'piqued'.

[Garrett]

Sorry yes "piqued" Had a few drinks and was in a hurry. Piqued.

cheers

garrett

On 2004-11-13 10:04:50 -0800, "normanstrong" > said:

>
> <Garrett Cox> wrote in message
> ...
>> How much to build the powersupply? I assume we'd be building it. I'd
> be
>> interested. I love reading the DIY also. Still want to piece
> together a
>> few of Scott Dorsey's passive EQ's. I hope it'd sound pretty awesome
>> 220 per channel is a bit of cash. I won't say steep but it is a DIY
>> project for almost 2 grand. (If you do 8 channels)
>>
>> mark me down for interest peaked.
>
> I think the word you're looking for there is 'piqued'.

[Mike Rivers]

In article > writes:

> In this design, you can leave out whatever you don't want;
> leaving out the high-pass filter will save $5-something per channel (the
> price of the switch), leaving out the balanced outputs will save about $16
> per channel. By leaving the phantom on all the time (global on/off switching
> only), you save another $5-something. So a stripped-down version would cost
> about $148 a channel.

Mr. Marketing here . . .

How about presenting it as a two-channel preamp which, I suspect, is
more in demand than an eight-channel preamp. Make a two-channel board
with pads to mount components for phantom powering, the high-pass
filter, and the additional components for the balanced output. Let the
user decide what extra features he wants to add for more flexibility
rather than what features he wants to leave out to save a few bucks.
The power supply will handle up to eight channels worth of boards, so
the preamp can grow as the users' needs grow.

The chassis, panel, and case will remain a stumbling block for many,
however.

--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> In this design, you can leave out whatever you don't want;
> leaving out the high-pass filter will save $5-something per channel (the
> price of the switch), leaving out the balanced outputs will save about $16
> per channel. By leaving the phantom on all the time (global on/off switching
> only), you save another $5-something. So a stripped-down version would cost
> about $148 a channel.

Mr. Marketing here . . .

How about presenting it as a two-channel preamp which, I suspect, is
more in demand than an eight-channel preamp. Make a two-channel board
with pads to mount components for phantom powering, the high-pass
filter, and the additional components for the balanced output. Let the
user decide what extra features he wants to add for more flexibility
rather than what features he wants to leave out to save a few bucks.
The power supply will handle up to eight channels worth of boards, so
the preamp can grow as the users' needs grow.

The chassis, panel, and case will remain a stumbling block for many,
however.

--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article .com> writes:

> A nice front panel is easy! You don't have to have a CNC mill yourself,
> and you don't have to struggle with the dremel. Check out Front Panel
> Express, or Schaeffer AG. The cost depends on the complexity of your
> panel, but it is quite reasonable, and cheap enough to be used on
> countless low budget DIY synth projects that I've seen.

I've heard of this outfit but have never investigated them. Why not
get an estimate for a project like this and pass it on to us? Don't
forget holes for the gain controls, high pass filter and phantom power
switches, might as well add a polarity switch, power supply connector,
and both inputs and outputs. Would you put the inputs on the front
(for convenience) or on the rear (for convenience <g>). That's two
panels, in case you weren't counting.

Do they make aluminum panels suitable for rack mounting that can
support the weight of eight transformers? (yeah, I know, it makes a
difference whether you mount them near the front or back). You'd
probably want a 3/16" or 1/4" thick front panel if that was also the
rack mount point, or at least an 1/8" panel with add-on rack ears.
Then you'd need a chassis and stand-offs to mount the circuit board.
All in all, a fair number of mechanical parts. This is why companies
that build electronic equipment have mechanical engineers working for
them, at least as consultants.




--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article .com> writes:

> A nice front panel is easy! You don't have to have a CNC mill yourself,
> and you don't have to struggle with the dremel. Check out Front Panel
> Express, or Schaeffer AG. The cost depends on the complexity of your
> panel, but it is quite reasonable, and cheap enough to be used on
> countless low budget DIY synth projects that I've seen.

I've heard of this outfit but have never investigated them. Why not
get an estimate for a project like this and pass it on to us? Don't
forget holes for the gain controls, high pass filter and phantom power
switches, might as well add a polarity switch, power supply connector,
and both inputs and outputs. Would you put the inputs on the front
(for convenience) or on the rear (for convenience <g>). That's two
panels, in case you weren't counting.

Do they make aluminum panels suitable for rack mounting that can
support the weight of eight transformers? (yeah, I know, it makes a
difference whether you mount them near the front or back). You'd
probably want a 3/16" or 1/4" thick front panel if that was also the
rack mount point, or at least an 1/8" panel with add-on rack ears.
Then you'd need a chassis and stand-offs to mount the circuit board.
All in all, a fair number of mechanical parts. This is why companies
that build electronic equipment have mechanical engineers working for
them, at least as consultants.




--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article <2004111313443316807%coxg@usfcaedu> writes:

> Personally, I wouldn't mind what it looked like as long as it sounded
> good and the 1500 or 1800 I spent was justified. I think the purpose
> for me would be just usability. No bling or whatever.

That's OK if you're doing it just for yourself and don't have a lot of
pride. But if you have a client coming in and you plug a mic into a
ragged looking box, what's he going to think?

--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article <2004111313443316807%coxg@usfcaedu> writes:

> Personally, I wouldn't mind what it looked like as long as it sounded
> good and the 1500 or 1800 I spent was justified. I think the purpose
> for me would be just usability. No bling or whatever.

That's OK if you're doing it just for yourself and don't have a lot of
pride. But if you have a client coming in and you plug a mic into a
ragged looking box, what's he going to think?

--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

> From: Bob Cain >

> > come up with a battery operated unit at
> > $50/channel.

At a trade show a couple of years back, Dan Kennedy sketched something
out for me on a yellow legal pad. I still have the sheet. I built up a
channel and it looked like it would work out fine, but I never
packaged it. Same old story.

> What I'm dying for is a four channel as per above but with a
> form of gain control that will allow any number of channels
> to be ganged and operated with a single control. Some kind
> precision voltage controled pot on each channel if such a
> thing exists.

Check out the Burr-Brown PGA2500. It's a digitally controlled mic
preamp chip. I'm not sure if I've heard one, but it's what Mackie is
using in the mic preamp module of their new dxb console. That module
appears to have a component made of unobtanium, maybe it's the
PGA2500.



--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

> From: Bob Cain >

> > come up with a battery operated unit at
> > $50/channel.

At a trade show a couple of years back, Dan Kennedy sketched something
out for me on a yellow legal pad. I still have the sheet. I built up a
channel and it looked like it would work out fine, but I never
packaged it. Same old story.

> What I'm dying for is a four channel as per above but with a
> form of gain control that will allow any number of channels
> to be ganged and operated with a single control. Some kind
> precision voltage controled pot on each channel if such a
> thing exists.

Check out the Burr-Brown PGA2500. It's a digitally controlled mic
preamp chip. I'm not sure if I've heard one, but it's what Mackie is
using in the mic preamp module of their new dxb console. That module
appears to have a component made of unobtanium, maybe it's the
PGA2500.



--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Scott Dorsey]

Kurt Albershardt > wrote:
>Mike Rivers wrote:
>>
>> Actually that isn't too difficult. If you're going to build a $2,000
>> preamp, you're probably into building things and you don't have to
>> start out by buying every tool that you need, because you already have
>> a decent shop. A good start for audio projects is a set of Greenlee
>> chassis punches for male and female XLR connectors, about $40 a piece.
>
>I thought these punches were more like $200-250 each? You are talking about the ones with the slots for the mounting screws, right?

No, he is talking about round Greenless punches, without holes for mounting
screws. You punch the hole, put in the connector, and then drill the screw
holes.

I did not know that there were ANY hand punches that will do all three holes
in one operation! If you know of one, I would really like to know. I have
used a small hydraulic press with custom tooling, a combination that cost a
lot more than $200 and was not convenient to take into the field. A hand punch
that would do all three holes would be wonderful for field modification work.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Kurt Albershardt > wrote:
>Mike Rivers wrote:
>>
>> Actually that isn't too difficult. If you're going to build a $2,000
>> preamp, you're probably into building things and you don't have to
>> start out by buying every tool that you need, because you already have
>> a decent shop. A good start for audio projects is a set of Greenlee
>> chassis punches for male and female XLR connectors, about $40 a piece.
>
>I thought these punches were more like $200-250 each? You are talking about the ones with the slots for the mounting screws, right?

No, he is talking about round Greenless punches, without holes for mounting
screws. You punch the hole, put in the connector, and then drill the screw
holes.

I did not know that there were ANY hand punches that will do all three holes
in one operation! If you know of one, I would really like to know. I have
used a small hydraulic press with custom tooling, a combination that cost a
lot more than $200 and was not convenient to take into the field. A hand punch
that would do all three holes would be wonderful for field modification work.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Bob Cain > wrote:
>Geoff Wood wrote:
>
>> I'd be more interested in variable input impedence.
>
>Which reminds me of a question that came up on another
>forum. Seems that pre impedences are down in the 2K Ohm and
>below range. Have they always been that low and why such a
>relatively big load?

Well, first of all because audio guys were used to dealing with 600 ohm
balanced lines for everything at the time (which is a holdover from telco
practice, which is a holdover from open wire transmission lines that had
a 600 ohm characteristic impedance). Or 150 ohm lines if you worked at
CBS.

Secondly, the low impedance reduces electrostatic noise pickup, which is
high voltage noise with not much induced current. The signal current
swamps the noise current.

50 ohm impedances were not unusual at one time, back when everything was
transformer coupled so the disadvantages of extremely low impedances were
not as great.

The major disadvantage of the low mike impedances is that you need such a
high ratio transformer to get it into the grid of the first preamp tube,
and high ratio transformers with good high end response are hard to make.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Bob Cain > wrote:
>Geoff Wood wrote:
>
>> I'd be more interested in variable input impedence.
>
>Which reminds me of a question that came up on another
>forum. Seems that pre impedences are down in the 2K Ohm and
>below range. Have they always been that low and why such a
>relatively big load?

Well, first of all because audio guys were used to dealing with 600 ohm
balanced lines for everything at the time (which is a holdover from telco
practice, which is a holdover from open wire transmission lines that had
a 600 ohm characteristic impedance). Or 150 ohm lines if you worked at
CBS.

Secondly, the low impedance reduces electrostatic noise pickup, which is
high voltage noise with not much induced current. The signal current
swamps the noise current.

50 ohm impedances were not unusual at one time, back when everything was
transformer coupled so the disadvantages of extremely low impedances were
not as great.

The major disadvantage of the low mike impedances is that you need such a
high ratio transformer to get it into the grid of the first preamp tube,
and high ratio transformers with good high end response are hard to make.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Paul Stamler]

"Mike Rivers" > wrote in message
news:znr1100391373k@trad...
>
> Mr. Marketing here . . .
>
> How about presenting it as a two-channel preamp which, I suspect, is
> more in demand than an eight-channel preamp. Make a two-channel board
> with pads to mount components for phantom powering, the high-pass
> filter, and the additional components for the balanced output. Let the
> user decide what extra features he wants to add for more flexibility
> rather than what features he wants to leave out to save a few bucks.
> The power supply will handle up to eight channels worth of boards, so
> the preamp can grow as the users' needs grow.

It's already a two-channel preamp if you only buy two preamp boards. And
since the users are buying the parts, they get to decide what to leave out.
I'll make it clear, if I market the boards, just what parts are mandatory
and what parts aren't.

> The chassis, panel, and case will remain a stumbling block for many,
> however.

But not all; I'm aiming this at folks who have had at least some experience
with DIY. And I have a guy who's willing to make and sell panels and/or
cases. If someone wanted fewer than 8 channels, they could always put plugs
into the unused front-panel holes.

Peace,
Paul

[Paul Stamler]

"Mike Rivers" > wrote in message
news:znr1100391373k@trad...
>
> Mr. Marketing here . . .
>
> How about presenting it as a two-channel preamp which, I suspect, is
> more in demand than an eight-channel preamp. Make a two-channel board
> with pads to mount components for phantom powering, the high-pass
> filter, and the additional components for the balanced output. Let the
> user decide what extra features he wants to add for more flexibility
> rather than what features he wants to leave out to save a few bucks.
> The power supply will handle up to eight channels worth of boards, so
> the preamp can grow as the users' needs grow.

It's already a two-channel preamp if you only buy two preamp boards. And
since the users are buying the parts, they get to decide what to leave out.
I'll make it clear, if I market the boards, just what parts are mandatory
and what parts aren't.

> The chassis, panel, and case will remain a stumbling block for many,
> however.

But not all; I'm aiming this at folks who have had at least some experience
with DIY. And I have a guy who's willing to make and sell panels and/or
cases. If someone wanted fewer than 8 channels, they could always put plugs
into the unused front-panel holes.

Peace,
Paul

[Paul Stamler]

"Mike Rivers" > wrote in message
news:znr1100392038k@trad...
>
> In article .com>
writes:
>
> > A nice front panel is easy! You don't have to have a CNC mill yourself,
> > and you don't have to struggle with the dremel. Check out Front Panel
> > Express, or Schaeffer AG. The cost depends on the complexity of your
> > panel, but it is quite reasonable, and cheap enough to be used on
> > countless low budget DIY synth projects that I've seen.
>
> I've heard of this outfit but have never investigated them. Why not
> get an estimate for a project like this and pass it on to us? Don't
> forget holes for the gain controls, high pass filter and phantom power
> switches, might as well add a polarity switch, power supply connector,
> and both inputs and outputs. Would you put the inputs on the front
> (for convenience) or on the rear (for convenience <g>). That's two
> panels, in case you weren't counting.

Rear. Eight XLR inputs and level controls take up a heck of a lot of space,
and getting your fingers in between all those plugs sounds like a real pain
in the butt. No polarity switch; I don't like putting switches into
mike-level circuits, having once nearly got fired when one decided to go
intermittent on me in the middle of a live broadcast. I could, I suppose,
put one in the balanced output section, but that wouldn't help the folks who
are recording or monitoring from the unbalanced outs, and a DPDT switch adds
more expense. I prefer to carry a couple of polarity-reversers in the BS
bag, for that one time in 100 when I need them.

> Do they make aluminum panels suitable for rack mounting that can
> support the weight of eight transformers? (yeah, I know, it makes a
> difference whether you mount them near the front or back). You'd
> probably want a 3/16" or 1/4" thick front panel if that was also the
> rack mount point, or at least an 1/8" panel with add-on rack ears.
> Then you'd need a chassis and stand-offs to mount the circuit board.
> All in all, a fair number of mechanical parts. This is why companies
> that build electronic equipment have mechanical engineers working for
> them, at least as consultants.

I've used Sescom boxes in the past, which have hefty side panels with rack
ears and fairly light front and rear panels, good for easy drilling and
punching. Each mike channel is on a circuit board of its own, mounted using
L-brackets to the bottom of the case. I thought about a single PC board, but
decided people who wanted only 2 or 4 channels would balk at the expense of
the 8-channel board.

Peace,
Paul

[Paul Stamler]

"Mike Rivers" > wrote in message
news:znr1100392038k@trad...
>
> In article .com>
writes:
>
> > A nice front panel is easy! You don't have to have a CNC mill yourself,
> > and you don't have to struggle with the dremel. Check out Front Panel
> > Express, or Schaeffer AG. The cost depends on the complexity of your
> > panel, but it is quite reasonable, and cheap enough to be used on
> > countless low budget DIY synth projects that I've seen.
>
> I've heard of this outfit but have never investigated them. Why not
> get an estimate for a project like this and pass it on to us? Don't
> forget holes for the gain controls, high pass filter and phantom power
> switches, might as well add a polarity switch, power supply connector,
> and both inputs and outputs. Would you put the inputs on the front
> (for convenience) or on the rear (for convenience <g>). That's two
> panels, in case you weren't counting.

Rear. Eight XLR inputs and level controls take up a heck of a lot of space,
and getting your fingers in between all those plugs sounds like a real pain
in the butt. No polarity switch; I don't like putting switches into
mike-level circuits, having once nearly got fired when one decided to go
intermittent on me in the middle of a live broadcast. I could, I suppose,
put one in the balanced output section, but that wouldn't help the folks who
are recording or monitoring from the unbalanced outs, and a DPDT switch adds
more expense. I prefer to carry a couple of polarity-reversers in the BS
bag, for that one time in 100 when I need them.

> Do they make aluminum panels suitable for rack mounting that can
> support the weight of eight transformers? (yeah, I know, it makes a
> difference whether you mount them near the front or back). You'd
> probably want a 3/16" or 1/4" thick front panel if that was also the
> rack mount point, or at least an 1/8" panel with add-on rack ears.
> Then you'd need a chassis and stand-offs to mount the circuit board.
> All in all, a fair number of mechanical parts. This is why companies
> that build electronic equipment have mechanical engineers working for
> them, at least as consultants.

I've used Sescom boxes in the past, which have hefty side panels with rack
ears and fairly light front and rear panels, good for easy drilling and
punching. Each mike channel is on a circuit board of its own, mounted using
L-brackets to the bottom of the case. I thought about a single PC board, but
decided people who wanted only 2 or 4 channels would balk at the expense of
the 8-channel board.

Peace,
Paul

[Frank Vuotto]

On 14 Nov 2004 06:59:08 -0500, (Mike Rivers)
wrote:

>The chassis, panel, and case will remain a stumbling block for many,
>however.


Amen, even for the experienced it usually takes twice as long to box
a project as it does to put together a circuit or perf board.


Frank /~ http://newmex.com/f10
@/

[Frank Vuotto]

On 14 Nov 2004 06:59:08 -0500, (Mike Rivers)
wrote:

>The chassis, panel, and case will remain a stumbling block for many,
>however.


Amen, even for the experienced it usually takes twice as long to box
a project as it does to put together a circuit or perf board.


Frank /~ http://newmex.com/f10
@/

[Mike Rivers]

In article > writes:

> About half of the cost of the preamp actually is in the power supply, and I
> worked very hard to try and bring the power supply parts cost down and try
> and do it entirely with Digi-Key parts. I was not able to do so. Everything
> I did to cut corners in the supply wound up affecting the sound too much.

The difference between Scott and some commercial manufacturers is that
he has the decency not to offer a product where cutting corners affect
the sound too much.


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> About half of the cost of the preamp actually is in the power supply, and I
> worked very hard to try and bring the power supply parts cost down and try
> and do it entirely with Digi-Key parts. I was not able to do so. Everything
> I did to cut corners in the supply wound up affecting the sound too much.

The difference between Scott and some commercial manufacturers is that
he has the decency not to offer a product where cutting corners affect
the sound too much.


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> > A good start for audio projects is a set of Greenlee
> > chassis punches for male and female XLR connectors, about $40 a piece.
>
> I thought these punches were more like $200-250 each? You are talking about
> the ones with the slots for the mounting screws, right?

No, punches that make 3/4" (male) and 15/16" (female) round holes.
There's a 3/8" bolt that draws the punch through the die, so you have
to be able to drill a 3/8" hole but that's easy enough with a Harry
Homeowner electric hand drill - though getting it in the right place
is a little tricky.

Markertek sells the punches. Look in their catalog under C for
"Chassis Punch" (at least that's how it's listed in the paper catalog
I have here).

Here ya go: http://www.markertek.com/SearchProduct.asp?item=GL730A&off=1

And on the next page, they have a 2 space rack mount chassis that takes
five of their panel modules front and rear (they come pre-punched for some
things useful like XLR connectors, or blank). The chassis is $65. Panels are
$6 - $10 and come up to triple width.

I took a look at the Sescom web page as Monte suggested and they have a
similar rack mount chassis with what looks like solid front and rear panels
for around $40 that would probably accommodate the preamp. They also
have chassis punches for the microphone connectors that are about half the
price of those from Markertek. Sescom doesn't specify a brand name
(Markertek's are from Greenlee who has been making them for about 50
years) so it's possible that the Sescom ones are Chinese. They're probably
fine for a couple of projects, but may not last through a lifetime of building.




--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> > A good start for audio projects is a set of Greenlee
> > chassis punches for male and female XLR connectors, about $40 a piece.
>
> I thought these punches were more like $200-250 each? You are talking about
> the ones with the slots for the mounting screws, right?

No, punches that make 3/4" (male) and 15/16" (female) round holes.
There's a 3/8" bolt that draws the punch through the die, so you have
to be able to drill a 3/8" hole but that's easy enough with a Harry
Homeowner electric hand drill - though getting it in the right place
is a little tricky.

Markertek sells the punches. Look in their catalog under C for
"Chassis Punch" (at least that's how it's listed in the paper catalog
I have here).

Here ya go: http://www.markertek.com/SearchProduct.asp?item=GL730A&off=1

And on the next page, they have a 2 space rack mount chassis that takes
five of their panel modules front and rear (they come pre-punched for some
things useful like XLR connectors, or blank). The chassis is $65. Panels are
$6 - $10 and come up to triple width.

I took a look at the Sescom web page as Monte suggested and they have a
similar rack mount chassis with what looks like solid front and rear panels
for around $40 that would probably accommodate the preamp. They also
have chassis punches for the microphone connectors that are about half the
price of those from Markertek. Sescom doesn't specify a brand name
(Markertek's are from Greenlee who has been making them for about 50
years) so it's possible that the Sescom ones are Chinese. They're probably
fine for a couple of projects, but may not last through a lifetime of building.




--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > -nospam writes:

> I'd be more interested in variable input impedence.

You could do it the easy way by just hanging a pot or switched fixed
resistors across the mic input terminals, or you could do it the
expensive (and more lifelike) way by using a tapped input transformer.



--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > -nospam writes:

> I'd be more interested in variable input impedence.

You could do it the easy way by just hanging a pot or switched fixed
resistors across the mic input terminals, or you could do it the
expensive (and more lifelike) way by using a tapped input transformer.



--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Kurt Albershardt]

Scott Dorsey wrote:
> Kurt Albershardt > wrote:
>
>> Mike Rivers wrote:
>>
>>> Actually that isn't too difficult. If you're going to build a $2,000
>>> preamp, you're probably into building things and you don't have to
>>> start out by buying every tool that you need, because you already have
>>> a decent shop. A good start for audio projects is a set of Greenlee
>>> chassis punches for male and female XLR connectors, about $40 a piece.
>>
>> I thought these punches were more like $200-250 each? You are talking about the ones with the slots for the mounting screws, right?
>
>
> No, he is talking about round Greenless punches, without holes for mounting
> screws. You punch the hole, put in the connector, and then drill the screw
> holes.

I can do that with a Unibit, unless it's a really thick panel.




> I did not know that there were ANY hand punches that will do all three holes
> in one operation! If you know of one, I would really like to know. I have
> used a small hydraulic press with custom tooling, a combination that cost a
> lot more than $200 and was not convenient to take into the field. A hand punch
> that would do all three holes would be wonderful for field modification work.

At a place I worked in Hollywood, we used to have a set (one for each connector sex.) It was a single hole with keyways (notches) for the mounting screws. I don't know who made them.

[Kurt Albershardt]

Scott Dorsey wrote:
> Kurt Albershardt > wrote:
>
>> Mike Rivers wrote:
>>
>>> Actually that isn't too difficult. If you're going to build a $2,000
>>> preamp, you're probably into building things and you don't have to
>>> start out by buying every tool that you need, because you already have
>>> a decent shop. A good start for audio projects is a set of Greenlee
>>> chassis punches for male and female XLR connectors, about $40 a piece.
>>
>> I thought these punches were more like $200-250 each? You are talking about the ones with the slots for the mounting screws, right?
>
>
> No, he is talking about round Greenless punches, without holes for mounting
> screws. You punch the hole, put in the connector, and then drill the screw
> holes.

I can do that with a Unibit, unless it's a really thick panel.




> I did not know that there were ANY hand punches that will do all three holes
> in one operation! If you know of one, I would really like to know. I have
> used a small hydraulic press with custom tooling, a combination that cost a
> lot more than $200 and was not convenient to take into the field. A hand punch
> that would do all three holes would be wonderful for field modification work.

At a place I worked in Hollywood, we used to have a set (one for each connector sex.) It was a single hole with keyways (notches) for the mounting screws. I don't know who made them.

[Kurt Albershardt]

Mike Rivers wrote:
>>From: Bob Cain >
>
>
>>>come up with a battery operated unit at
>>>$50/channel.
>
>
> At a trade show a couple of years back, Dan Kennedy sketched something
> out for me on a yellow legal pad. I still have the sheet. I built up a
> channel and it looked like it would work out fine, but I never
> packaged it. Same old story.
>
>
>>What I'm dying for is a four channel as per above but with a
>>form of gain control that will allow any number of channels
>>to be ganged and operated with a single control. Some kind
>>precision voltage controled pot on each channel if such a
>>thing exists.
>
>
> Check out the Burr-Brown PGA2500. It's a digitally controlled mic
> preamp chip. I'm not sure if I've heard one, but it's what Mackie is
> using in the mic preamp module of their new dxb console. That module
> appears to have a component made of unobtanium, maybe it's the
> PGA2500.

$16.58 in single unit quantities from Digi-Key. Surely this ought to find its way into some affordable remote digital preamp packages soon?

[Kurt Albershardt]

Mike Rivers wrote:
>>From: Bob Cain >
>
>
>>>come up with a battery operated unit at
>>>$50/channel.
>
>
> At a trade show a couple of years back, Dan Kennedy sketched something
> out for me on a yellow legal pad. I still have the sheet. I built up a
> channel and it looked like it would work out fine, but I never
> packaged it. Same old story.
>
>
>>What I'm dying for is a four channel as per above but with a
>>form of gain control that will allow any number of channels
>>to be ganged and operated with a single control. Some kind
>>precision voltage controled pot on each channel if such a
>>thing exists.
>
>
> Check out the Burr-Brown PGA2500. It's a digitally controlled mic
> preamp chip. I'm not sure if I've heard one, but it's what Mackie is
> using in the mic preamp module of their new dxb console. That module
> appears to have a component made of unobtanium, maybe it's the
> PGA2500.

$16.58 in single unit quantities from Digi-Key. Surely this ought to find its way into some affordable remote digital preamp packages soon?

[Mike Rivers]

In article > writes:

> It's already a two-channel preamp if you only buy two preamp boards. And
> since the users are buying the parts, they get to decide what to leave out.

I know that and you know that, but it's an easier sell to tell them
what they can add if they want more capability than to tell them what
they can leave out if they want less capability. It's a psychological
thing. People don't want to admit that they can live with less if more
is offered to them.


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> I did not know that there were ANY hand punches that will do all three holes
> in one operation! If you know of one, I would really like to know.

I think I've seen a DB25 hole punch that also punches the mounting
holes. But it's a prettly clumsy thing, and costs about $100.




--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> It's already a two-channel preamp if you only buy two preamp boards. And
> since the users are buying the parts, they get to decide what to leave out.

I know that and you know that, but it's an easier sell to tell them
what they can add if they want more capability than to tell them what
they can leave out if they want less capability. It's a psychological
thing. People don't want to admit that they can live with less if more
is offered to them.


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> I did not know that there were ANY hand punches that will do all three holes
> in one operation! If you know of one, I would really like to know.

I think I've seen a DB25 hole punch that also punches the mounting
holes. But it's a prettly clumsy thing, and costs about $100.




--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Bob Cain]

Mike Rivers wrote:

> Check out the Burr-Brown PGA2500. It's a digitally controlled mic
> preamp chip. I'm not sure if I've heard one, but it's what Mackie is
> using in the mic preamp module of their new dxb console. That module
> appears to have a component made of unobtanium, maybe it's the
> PGA2500.

Wow! That certainly is the ticket for my app. Cascadable
too for ganging. Only problem I see is the need for a PIC
to convert an analog voltage from a gain pot to the digital
gain control for the chips. PICs are cheap, but there would
certainly be a learning curve and development investment for
progamming one to do the job.

At $16.50 for the PGA2500 and a buck for a PIC, this
certainly should offer the low cost channel that many people
have been wanting. The -128 dB noise Ein isn't stellar by
any means but certainly usable.

This might just be worth kitting.


Thanks,

Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

[Bob Cain]

Mike Rivers wrote:

> Check out the Burr-Brown PGA2500. It's a digitally controlled mic
> preamp chip. I'm not sure if I've heard one, but it's what Mackie is
> using in the mic preamp module of their new dxb console. That module
> appears to have a component made of unobtanium, maybe it's the
> PGA2500.

Wow! That certainly is the ticket for my app. Cascadable
too for ganging. Only problem I see is the need for a PIC
to convert an analog voltage from a gain pot to the digital
gain control for the chips. PICs are cheap, but there would
certainly be a learning curve and development investment for
progamming one to do the job.

At $16.50 for the PGA2500 and a buck for a PIC, this
certainly should offer the low cost channel that many people
have been wanting. The -128 dB noise Ein isn't stellar by
any means but certainly usable.

This might just be worth kitting.


Thanks,

Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

[Magnus Jans?n]

(Mike Rivers) wrote in message news:<znr1100380037k@trad>...
> In article > writes:
>
> > I have some general opinions on magazine-published DIY projects, and
> > this is aimed not only at Mr Stamler but also Mr Dorsey and everyone
> > else that do these things.
> >
> > First, I want to be able to get ALL parts at once from one place, and
> > that must include the chassis.
>
> That's really nice, but unless someone is willing to put together a
> complete kit, it really can't be done. Paia used to do this but they
> don't seem to be quite so active in that area these days. Understand
> that this requires a substantial investment when it comes to
> metalwork. They can often use resistors, capacitors and op amp chips
> for multiple products but they can't punch a chassis for an 8-channel
> mic preamp and use it for a compressor.

Scott Hampton seems to manage just fine. Of course there isn't a
decent business in doing kits, but Mr Dorsey et al arn't making any
money on the kits as it so... As a naive end-user/reader it's hard to
see the difference in not making much money on "hard to get parts for
and then I have to slave away on housing"-kits and not making much
money on "yummy it's just one package to order for off-hours soldering
goodness". Just add the extra labor costs onto the cost of the full
package to take you from "losing money" to "not making much money".

> > Second, I don't think anyone is interested in merly "decent" or
> > "servicable" projects. I think most readers have too much of that
> > already. We want "really good" or even "outstanding".
>
> This is why I didn't think Paul's project would be a smashing success.
> On the other hand, a project like Scott's Oktava mic modifications
> that involve a simple circuit board that he can provide, a handful of
> parts, and only small hand tools are pretty popular.

Yes it's an examplary mod. Unfortunately he does in fact NOT provide
replacement circuit bords as you say, which I kind of whish he did
since he mentions about a million times how easy it is to wreck the
board. I wonder, would there be enough room to make it have a truly
balanced output if one redesigned the board?

> > To keep price down I think you need to make costly features optional.
> > Many people couldn't care less about HP-filtering, phase switches,
> > metering and balanced outputs in a preamp for instance.
>
> I wrote an article in Recording a while back about developing your own
> DIY project (using a monitor switcher as an example) in which I
> explained exactly that concept - but the point of my article was that
> YOU could make those decisions. It's not difficult to find application
> notes for transfomrers and op amps that will get you a decent mic
> preamp and you can make it "really good" or even "outstanding" by the
> way you apply what's in those application notes. If you want someone
> to make those decisions for you, you have to accept his take on what's
> good for you.

The problem is that "DIY" is not a good term for what we are
discussing. It's not so much "Do It Yourself" as "Someone Else Did
Most Of It For Me And Now I Just Paint By Numbers" (SEDMOIFMANIJPBN).
The reason why me and my ilk have to read your articles is because we
are in fact NOT skilled enough to concieve and design these things. We
can however build them. But since we are already pampered rather
heavily it feels ardenous to have to make the final set of decisions
ourselves (housing).


> This is a perfectly good example of a project that you could develop
> yourself. All you need to do is understand what you need to
> accomplish. Package it as pretty or as ugly as you wish.

But I don't want to develop it myself. I want to pay YOU to do it. I
want you to guide me through the design in the assembly notes,
explaining what each thing does, why this is good design practice etc.
So that at the end of assembling I may have learnt something. That's
ALL I want.
If I wanted to become an audio equipment designer of such a caliber
that I could design these things myself then I would study to become
one and not waste time trying to deduct something from a paint by
numbers DIY project.

[Magnus Jans?n]

(Mike Rivers) wrote in message news:<znr1100380037k@trad>...
> In article > writes:
>
> > I have some general opinions on magazine-published DIY projects, and
> > this is aimed not only at Mr Stamler but also Mr Dorsey and everyone
> > else that do these things.
> >
> > First, I want to be able to get ALL parts at once from one place, and
> > that must include the chassis.
>
> That's really nice, but unless someone is willing to put together a
> complete kit, it really can't be done. Paia used to do this but they
> don't seem to be quite so active in that area these days. Understand
> that this requires a substantial investment when it comes to
> metalwork. They can often use resistors, capacitors and op amp chips
> for multiple products but they can't punch a chassis for an 8-channel
> mic preamp and use it for a compressor.

Scott Hampton seems to manage just fine. Of course there isn't a
decent business in doing kits, but Mr Dorsey et al arn't making any
money on the kits as it so... As a naive end-user/reader it's hard to
see the difference in not making much money on "hard to get parts for
and then I have to slave away on housing"-kits and not making much
money on "yummy it's just one package to order for off-hours soldering
goodness". Just add the extra labor costs onto the cost of the full
package to take you from "losing money" to "not making much money".

> > Second, I don't think anyone is interested in merly "decent" or
> > "servicable" projects. I think most readers have too much of that
> > already. We want "really good" or even "outstanding".
>
> This is why I didn't think Paul's project would be a smashing success.
> On the other hand, a project like Scott's Oktava mic modifications
> that involve a simple circuit board that he can provide, a handful of
> parts, and only small hand tools are pretty popular.

Yes it's an examplary mod. Unfortunately he does in fact NOT provide
replacement circuit bords as you say, which I kind of whish he did
since he mentions about a million times how easy it is to wreck the
board. I wonder, would there be enough room to make it have a truly
balanced output if one redesigned the board?

> > To keep price down I think you need to make costly features optional.
> > Many people couldn't care less about HP-filtering, phase switches,
> > metering and balanced outputs in a preamp for instance.
>
> I wrote an article in Recording a while back about developing your own
> DIY project (using a monitor switcher as an example) in which I
> explained exactly that concept - but the point of my article was that
> YOU could make those decisions. It's not difficult to find application
> notes for transfomrers and op amps that will get you a decent mic
> preamp and you can make it "really good" or even "outstanding" by the
> way you apply what's in those application notes. If you want someone
> to make those decisions for you, you have to accept his take on what's
> good for you.

The problem is that "DIY" is not a good term for what we are
discussing. It's not so much "Do It Yourself" as "Someone Else Did
Most Of It For Me And Now I Just Paint By Numbers" (SEDMOIFMANIJPBN).
The reason why me and my ilk have to read your articles is because we
are in fact NOT skilled enough to concieve and design these things. We
can however build them. But since we are already pampered rather
heavily it feels ardenous to have to make the final set of decisions
ourselves (housing).


> This is a perfectly good example of a project that you could develop
> yourself. All you need to do is understand what you need to
> accomplish. Package it as pretty or as ugly as you wish.

But I don't want to develop it myself. I want to pay YOU to do it. I
want you to guide me through the design in the assembly notes,
explaining what each thing does, why this is good design practice etc.
So that at the end of assembling I may have learnt something. That's
ALL I want.
If I wanted to become an audio equipment designer of such a caliber
that I could design these things myself then I would study to become
one and not waste time trying to deduct something from a paint by
numbers DIY project.

[Scott Dorsey]

Kurt Albershardt > wrote:
>Scott Dorsey wrote:
>
>> I did not know that there were ANY hand punches that will do all three holes
>> in one operation! If you know of one, I would really like to know. I have
>> used a small hydraulic press with custom tooling, a combination that cost a
>> lot more than $200 and was not convenient to take into the field. A hand punch
>> that would do all three holes would be wonderful for field modification work.
>
>At a place I worked in Hollywood, we used to have a set (one for each connector sex.) It was a single hole with keyways (notches) for the mounting screws. I don't know who made them.

That is exactly what I want! Where do I get them? A couple hundred bucks
each is doable if they last.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Kurt Albershardt > wrote:
>Scott Dorsey wrote:
>
>> I did not know that there were ANY hand punches that will do all three holes
>> in one operation! If you know of one, I would really like to know. I have
>> used a small hydraulic press with custom tooling, a combination that cost a
>> lot more than $200 and was not convenient to take into the field. A hand punch
>> that would do all three holes would be wonderful for field modification work.
>
>At a place I worked in Hollywood, we used to have a set (one for each connector sex.) It was a single hole with keyways (notches) for the mounting screws. I don't know who made them.

That is exactly what I want! Where do I get them? A couple hundred bucks
each is doable if they last.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Bob Cain > wrote:
>
>Wow! That certainly is the ticket for my app. Cascadable
>too for ganging. Only problem I see is the need for a PIC
>to convert an analog voltage from a gain pot to the digital
>gain control for the chips. PICs are cheap, but there would
>certainly be a learning curve and development investment for
>progamming one to do the job.

Skip the PIC and the pot. Use an optical encoder. It will take some glue
logic, but not all that much, and TTL is cheap.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Bob Cain > wrote:
>
>Wow! That certainly is the ticket for my app. Cascadable
>too for ganging. Only problem I see is the need for a PIC
>to convert an analog voltage from a gain pot to the digital
>gain control for the chips. PICs are cheap, but there would
>certainly be a learning curve and development investment for
>progamming one to do the job.

Skip the PIC and the pot. Use an optical encoder. It will take some glue
logic, but not all that much, and TTL is cheap.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Kurt Albershardt]

Scott Dorsey wrote:
> Kurt Albershardt > wrote:
>
>> Scott Dorsey wrote:
>>
>>
>>> I did not know that there were ANY hand punches that will do all three holes
>>> in one operation! If you know of one, I would really like to know. I have
>>> used a small hydraulic press with custom tooling, a combination that cost a
>>> lot more than $200 and was not convenient to take into the field. A hand punch
>>> that would do all three holes would be wonderful for field modification work.
>>
>> At a place I worked in Hollywood, we used to have a set (one for each connector sex.) It was a single hole with keyways (notches) for the mounting screws. I don't know who made them.
>
>
> That is exactly what I want! Where do I get them? A couple hundred bucks
> each is doable if they last.

They were $200+ in 1984, and I still don't know where they came from.

[Kurt Albershardt]

Scott Dorsey wrote:
> Kurt Albershardt > wrote:
>
>> Scott Dorsey wrote:
>>
>>
>>> I did not know that there were ANY hand punches that will do all three holes
>>> in one operation! If you know of one, I would really like to know. I have
>>> used a small hydraulic press with custom tooling, a combination that cost a
>>> lot more than $200 and was not convenient to take into the field. A hand punch
>>> that would do all three holes would be wonderful for field modification work.
>>
>> At a place I worked in Hollywood, we used to have a set (one for each connector sex.) It was a single hole with keyways (notches) for the mounting screws. I don't know who made them.
>
>
> That is exactly what I want! Where do I get them? A couple hundred bucks
> each is doable if they last.

They were $200+ in 1984, and I still don't know where they came from.

[Mike Rivers]

In article > writes:

> > Check out the Burr-Brown PGA2500.

> Wow! That certainly is the ticket for my app. Cascadable
> too for ganging. Only problem I see is the need for a PIC
> to convert an analog voltage from a gain pot to the digital
> gain control for the chips. PICs are cheap, but there would
> certainly be a learning curve and development investment for
> progamming one to do the job.

I don't know what kind of digital input it wants for gain control. I
was thinking of an encoder with a knob, but I'll bet that being an
electro-mechanical device it would be a whole lot more expensive than
something all digital (assuming the programming came free <g>).


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> > Check out the Burr-Brown PGA2500.

> Wow! That certainly is the ticket for my app. Cascadable
> too for ganging. Only problem I see is the need for a PIC
> to convert an analog voltage from a gain pot to the digital
> gain control for the chips. PICs are cheap, but there would
> certainly be a learning curve and development investment for
> progamming one to do the job.

I don't know what kind of digital input it wants for gain control. I
was thinking of an encoder with a knob, but I'll bet that being an
electro-mechanical device it would be a whole lot more expensive than
something all digital (assuming the programming came free <g>).


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Scott Dorsey]

Paul Stamler > wrote:
>"Scott Dorsey" > wrote in message
...
>
>> About half of the cost of the preamp actually is in the power supply, and
>I
>> worked very hard to try and bring the power supply parts cost down and try
>> and do it entirely with Digi-Key parts. I was not able to do so.
>Everything
>> I did to cut corners in the supply wound up affecting the sound too much.
>
>Scott, try Allied. The new catalog has a surprising number of
>tube-compatible power transformers. Combine them with Digi-Key plus a tube
>supplier and you may bring the number of suppliers down to three.

Power transformers are easy, as long as you can pay $40 for the thing. I
had some ideas like using a transformer with a dual primary ($7.50 from
Talema) and using one of the secondaries to get 120VAC and then run that
into a doubler. Or use two filament transformers back-to-back. Even with
serious regulation and lots of shunt capacitance, these were just not stiff
enough.

The Hammond transformers I can get from AES, which also has the tubes and
the tube sockets. But resistors, switches, and miscellany all comes from
Digi-Key, the board comes from me, the case comes from Sescom or BUD, the
input transformers from Lundahl.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Paul Stamler > wrote:
>"Scott Dorsey" > wrote in message
...
>
>> About half of the cost of the preamp actually is in the power supply, and
>I
>> worked very hard to try and bring the power supply parts cost down and try
>> and do it entirely with Digi-Key parts. I was not able to do so.
>Everything
>> I did to cut corners in the supply wound up affecting the sound too much.
>
>Scott, try Allied. The new catalog has a surprising number of
>tube-compatible power transformers. Combine them with Digi-Key plus a tube
>supplier and you may bring the number of suppliers down to three.

Power transformers are easy, as long as you can pay $40 for the thing. I
had some ideas like using a transformer with a dual primary ($7.50 from
Talema) and using one of the secondaries to get 120VAC and then run that
into a doubler. Or use two filament transformers back-to-back. Even with
serious regulation and lots of shunt capacitance, these were just not stiff
enough.

The Hammond transformers I can get from AES, which also has the tubes and
the tube sockets. But resistors, switches, and miscellany all comes from
Digi-Key, the board comes from me, the case comes from Sescom or BUD, the
input transformers from Lundahl.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Geoff Wood]

"Kurt Albershardt" > wrote in message news:2vpphmF2mb4i0U1@uni->
> $16.58 in single unit quantities from Digi-Key. Surely this ought to find
> its way into some affordable remote digital preamp packages soon?


Is it supposed to sound any good ?

geoff

[Geoff Wood]

"Kurt Albershardt" > wrote in message news:2vpphmF2mb4i0U1@uni->
> $16.58 in single unit quantities from Digi-Key. Surely this ought to find
> its way into some affordable remote digital preamp packages soon?


Is it supposed to sound any good ?

geoff

[Geoff Wood]

"Mike Rivers" > wrote in message

> Markertek sells the punches. Look in their catalog under C for
> "Chassis Punch" (at least that's how it's listed in the paper catalog
> I have here).

I got one from either Studiospares or RS COmponents, that does for
Cannon-size panel mount XLRs. Problem is that many newer ones are
narrower...

geoff

[Geoff Wood]

"Mike Rivers" > wrote in message

> Markertek sells the punches. Look in their catalog under C for
> "Chassis Punch" (at least that's how it's listed in the paper catalog
> I have here).

I got one from either Studiospares or RS COmponents, that does for
Cannon-size panel mount XLRs. Problem is that many newer ones are
narrower...

geoff

[Paul Stamler]

"Mike Rivers" > wrote in message
news:znr1100435598k@trad...
>
> In article > -nospam
writes:
>
> > I'd be more interested in variable input impedence.
>
> You could do it the easy way by just hanging a pot or switched fixed
> resistors across the mic input terminals, or you could do it the
> expensive (and more lifelike) way by using a tapped input transformer.

Unfortunately, tapped input transformers are thin on the ground these days,
and good ones are even thinner.

Peace,
Paul

[Paul Stamler]

"Mike Rivers" > wrote in message
news:znr1100435598k@trad...
>
> In article > -nospam
writes:
>
> > I'd be more interested in variable input impedence.
>
> You could do it the easy way by just hanging a pot or switched fixed
> resistors across the mic input terminals, or you could do it the
> expensive (and more lifelike) way by using a tapped input transformer.

Unfortunately, tapped input transformers are thin on the ground these days,
and good ones are even thinner.

Peace,
Paul

[Bob Cain]

Scott Dorsey wrote:
> Bob Cain > wrote:
>
>>Wow! That certainly is the ticket for my app. Cascadable
>>too for ganging. Only problem I see is the need for a PIC
>>to convert an analog voltage from a gain pot to the digital
>>gain control for the chips. PICs are cheap, but there would
>>certainly be a learning curve and development investment for
>>progamming one to do the job.
>
>
> Skip the PIC and the pot. Use an optical encoder. It will take some glue
> logic, but not all that much, and TTL is cheap.

It's not pulse based. You send it serial frames with the
gain and various other options coded as fields in the frame.
At the least it would take a programmable logic part to
assemble the frame and send it. A PIC would probably be the
easiest approach in the end.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

[Bob Cain]

Scott Dorsey wrote:
> Bob Cain > wrote:
>
>>Wow! That certainly is the ticket for my app. Cascadable
>>too for ganging. Only problem I see is the need for a PIC
>>to convert an analog voltage from a gain pot to the digital
>>gain control for the chips. PICs are cheap, but there would
>>certainly be a learning curve and development investment for
>>progamming one to do the job.
>
>
> Skip the PIC and the pot. Use an optical encoder. It will take some glue
> logic, but not all that much, and TTL is cheap.

It's not pulse based. You send it serial frames with the
gain and various other options coded as fields in the frame.
At the least it would take a programmable logic part to
assemble the frame and send it. A PIC would probably be the
easiest approach in the end.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

[Mike Rivers]

In article > writes:

> [Oktava mic mod]. Unfortunately he does in fact NOT provide
> replacement circuit bords as you say, which I kind of whish he did
> since he mentions about a million times how easy it is to wreck the
> board. I wonder, would there be enough room to make it have a truly
> balanced output if one redesigned the board?

Sorry, I guess I was thinking of one of Scott's other projects that
does involve a circuit board.

> The problem is that "DIY" is not a good term for what we are
> discussing. It's not so much "Do It Yourself" as "Someone Else Did
> Most Of It For Me And Now I Just Paint By Numbers" (SEDMOIFMANIJPBN).

DING!!! We have a winner!

> The reason why me and my ilk have to read your articles is because we
> are in fact NOT skilled enough to concieve and design these things.

The point of my article was that there are useful things that you ARE
able to design. Mic preamps may be next to rocket science, but
switches and attenuators aren't. And once you realize that you CAN do
some designing, you may be encouraged to go further with your next
project.

> But I don't want to develop it myself. I want to pay YOU to do it. I
> want you to guide me through the design in the assembly notes,

Do that and you'll pay more than you can buy a commercially made
functional equivalent. What you can make probably won't be better, and
it sure won't look better. Used to be that the only way you could get
stuff was to build it yourself - studios in the '60s all built their
own consoles. But today there are perfectly good manufacturers making
quality products for about the cost of parts to an individual.

> explaining what each thing does, why this is good design practice etc.
> So that at the end of assembling I may have learnt something. That's
> ALL I want.

Well there is some benefit to that. Put it together and you'll have a
better idea of how to fix it when it breaks.

In a world where everyone builds his own computer, frankly I want to
have someone else find all the parts, fit them together, and deliver
something that I know will work when I turn it on.



--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> [Oktava mic mod]. Unfortunately he does in fact NOT provide
> replacement circuit bords as you say, which I kind of whish he did
> since he mentions about a million times how easy it is to wreck the
> board. I wonder, would there be enough room to make it have a truly
> balanced output if one redesigned the board?

Sorry, I guess I was thinking of one of Scott's other projects that
does involve a circuit board.

> The problem is that "DIY" is not a good term for what we are
> discussing. It's not so much "Do It Yourself" as "Someone Else Did
> Most Of It For Me And Now I Just Paint By Numbers" (SEDMOIFMANIJPBN).

DING!!! We have a winner!

> The reason why me and my ilk have to read your articles is because we
> are in fact NOT skilled enough to concieve and design these things.

The point of my article was that there are useful things that you ARE
able to design. Mic preamps may be next to rocket science, but
switches and attenuators aren't. And once you realize that you CAN do
some designing, you may be encouraged to go further with your next
project.

> But I don't want to develop it myself. I want to pay YOU to do it. I
> want you to guide me through the design in the assembly notes,

Do that and you'll pay more than you can buy a commercially made
functional equivalent. What you can make probably won't be better, and
it sure won't look better. Used to be that the only way you could get
stuff was to build it yourself - studios in the '60s all built their
own consoles. But today there are perfectly good manufacturers making
quality products for about the cost of parts to an individual.

> explaining what each thing does, why this is good design practice etc.
> So that at the end of assembling I may have learnt something. That's
> ALL I want.

Well there is some benefit to that. Put it together and you'll have a
better idea of how to fix it when it breaks.

In a world where everyone builds his own computer, frankly I want to
have someone else find all the parts, fit them together, and deliver
something that I know will work when I turn it on.



--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Dan Kennedy]

Greenlee makes 'em, and they are more like $410 in my McMaster-Carr
catalog, but just below them is another brand that makes you drill
3 holes, not just one for $189 to $239 depending on size.



Kurt Albershardt wrote:
> Scott Dorsey wrote:
>
>> Kurt Albershardt > wrote:
>>
>>> Scott Dorsey wrote:
>>>
>>>
>>>> I did not know that there were ANY hand punches that will do all
>>>> three holes
>>>> in one operation! If you know of one, I would really like to know.
>>>> I have
>>>> used a small hydraulic press with custom tooling, a combination that
>>>> cost a
>>>> lot more than $200 and was not convenient to take into the field. A
>>>> hand punch
>>>> that would do all three holes would be wonderful for field
>>>> modification work.
>>>
>>>
>>> At a place I worked in Hollywood, we used to have a set (one for each
>>> connector sex.) It was a single hole with keyways (notches) for the
>>> mounting screws. I don't know who made them.
>>
>>
>>
>> That is exactly what I want! Where do I get them? A couple hundred
>> bucks each is doable if they last.
>
>
> They were $200+ in 1984, and I still don't know where they came from.
>
>

[Dan Kennedy]

Greenlee makes 'em, and they are more like $410 in my McMaster-Carr
catalog, but just below them is another brand that makes you drill
3 holes, not just one for $189 to $239 depending on size.



Kurt Albershardt wrote:
> Scott Dorsey wrote:
>
>> Kurt Albershardt > wrote:
>>
>>> Scott Dorsey wrote:
>>>
>>>
>>>> I did not know that there were ANY hand punches that will do all
>>>> three holes
>>>> in one operation! If you know of one, I would really like to know.
>>>> I have
>>>> used a small hydraulic press with custom tooling, a combination that
>>>> cost a
>>>> lot more than $200 and was not convenient to take into the field. A
>>>> hand punch
>>>> that would do all three holes would be wonderful for field
>>>> modification work.
>>>
>>>
>>> At a place I worked in Hollywood, we used to have a set (one for each
>>> connector sex.) It was a single hole with keyways (notches) for the
>>> mounting screws. I don't know who made them.
>>
>>
>>
>> That is exactly what I want! Where do I get them? A couple hundred
>> bucks each is doable if they last.
>
>
> They were $200+ in 1984, and I still don't know where they came from.
>
>

[Mike Rivers]

In article > writes:

> The Hammond transformers I can get from AES, which also has the tubes and
> the tube sockets. But resistors, switches, and miscellany all comes from
> Digi-Key, the board comes from me, the case comes from Sescom or BUD, the
> input transformers from Lundahl.

Such is the life of a do-it-yourselfer. As someone pointed out here
yesterday, he wants a Heathkit. Probably also wants complete assembly
instructions in the package so he doesn't have to work from a magazine
article, too. Apparently there are is at least one person doing that
(Hamptone) - selling the preamp kitted as he does for his own
manufacturing process. This is possible if your production rate is
really small, you don't farm out assembly labor, and you can afford to
have a few unassembled kits on the shelf - either you assemble one
when you get an order for a finished unit or you ship out the kit when
you get an order for a kit. But I suspect that his "kits" include
pre-punched panels - he doesn't take a piece of aluminum off the shelf
and start drilling and punching when he gets an order.

The practicality of this is a function of the popularity of the item.
And the popularity of the item is a function of the bang for the buck.
So if you can offer a lot of functionality for a low unassembled
price, it might just be too popular to be able to handle the orders.
It's a hard battle to win.


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> The Hammond transformers I can get from AES, which also has the tubes and
> the tube sockets. But resistors, switches, and miscellany all comes from
> Digi-Key, the board comes from me, the case comes from Sescom or BUD, the
> input transformers from Lundahl.

Such is the life of a do-it-yourselfer. As someone pointed out here
yesterday, he wants a Heathkit. Probably also wants complete assembly
instructions in the package so he doesn't have to work from a magazine
article, too. Apparently there are is at least one person doing that
(Hamptone) - selling the preamp kitted as he does for his own
manufacturing process. This is possible if your production rate is
really small, you don't farm out assembly labor, and you can afford to
have a few unassembled kits on the shelf - either you assemble one
when you get an order for a finished unit or you ship out the kit when
you get an order for a kit. But I suspect that his "kits" include
pre-punched panels - he doesn't take a piece of aluminum off the shelf
and start drilling and punching when he gets an order.

The practicality of this is a function of the popularity of the item.
And the popularity of the item is a function of the bang for the buck.
So if you can offer a lot of functionality for a low unassembled
price, it might just be too popular to be able to handle the orders.
It's a hard battle to win.


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > -nospam writes:

> > "Chassis Punch" (at least that's how it's listed in the paper catalog
> > I have here).
>
> I got one from either Studiospares or RS COmponents, that does for
> Cannon-size panel mount XLRs. Problem is that many newer ones are
> narrower...

I noticed that either Sescom or Markertek also has a 24 mm punch for
Neutrik female connectors. That's slightly smaller than 15/16", but
I've found that the 15/16" punch works fine for either. That's the one
I would buy if I was buying just one - then I wouldn't have to ream
out the holes if I bought the other brand of connector.


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > -nospam writes:

> > "Chassis Punch" (at least that's how it's listed in the paper catalog
> > I have here).
>
> I got one from either Studiospares or RS COmponents, that does for
> Cannon-size panel mount XLRs. Problem is that many newer ones are
> narrower...

I noticed that either Sescom or Markertek also has a 24 mm punch for
Neutrik female connectors. That's slightly smaller than 15/16", but
I've found that the 15/16" punch works fine for either. That's the one
I would buy if I was buying just one - then I wouldn't have to ream
out the holes if I bought the other brand of connector.


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Scott Dorsey]

Geoff Wood -nospam> wrote:
>
>"Kurt Albershardt" > wrote in message news:2vpphmF2mb4i0U1@uni->
>> $16.58 in single unit quantities from Digi-Key. Surely this ought to find
>> its way into some affordable remote digital preamp packages soon?
>
>Is it supposed to sound any good ?

I am really suspicious of anything based on CMOS switching of any sort
inside.

But then, I'd do this with five relays and five resistors. That gives you
32 possible gain settings, which is better than most stepped attenuators.
It's not more than twice as expensive either, if you use the Omron relays.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Geoff Wood -nospam> wrote:
>
>"Kurt Albershardt" > wrote in message news:2vpphmF2mb4i0U1@uni->
>> $16.58 in single unit quantities from Digi-Key. Surely this ought to find
>> its way into some affordable remote digital preamp packages soon?
>
>Is it supposed to sound any good ?

I am really suspicious of anything based on CMOS switching of any sort
inside.

But then, I'd do this with five relays and five resistors. That gives you
32 possible gain settings, which is better than most stepped attenuators.
It's not more than twice as expensive either, if you use the Omron relays.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Geoff Wood -nospam> wrote:
>"Mike Rivers" > wrote in message
>
>> Markertek sells the punches. Look in their catalog under C for
>> "Chassis Punch" (at least that's how it's listed in the paper catalog
>> I have here).
>
>I got one from either Studiospares or RS COmponents, that does for
>Cannon-size panel mount XLRs. Problem is that many newer ones are
>narrower...

The narrower ones mostly need a 15/16" Greenlee punch. Available at your
local industrial supplier.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Geoff Wood -nospam> wrote:
>"Mike Rivers" > wrote in message
>
>> Markertek sells the punches. Look in their catalog under C for
>> "Chassis Punch" (at least that's how it's listed in the paper catalog
>> I have here).
>
>I got one from either Studiospares or RS COmponents, that does for
>Cannon-size panel mount XLRs. Problem is that many newer ones are
>narrower...

The narrower ones mostly need a 15/16" Greenlee punch. Available at your
local industrial supplier.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Paul Stamler > wrote:
>"Mike Rivers" > wrote in message
>news:znr1100435598k@trad...
>>
>> In article > -nospam
>writes:
>>
>> > I'd be more interested in variable input impedence.
>>
>> You could do it the easy way by just hanging a pot or switched fixed
>> resistors across the mic input terminals, or you could do it the
>> expensive (and more lifelike) way by using a tapped input transformer.
>
>Unfortunately, tapped input transformers are thin on the ground these days,
>and good ones are even thinner.

Lundahl has a very nice selection! And they aren't all that expensive
either.

I have been talking with Renco about doing some low ratio ones; they did
a marvelous job with some multitapped inductors for me. I can't say enough
good things about the Renco guys for inductors.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Paul Stamler > wrote:
>"Mike Rivers" > wrote in message
>news:znr1100435598k@trad...
>>
>> In article > -nospam
>writes:
>>
>> > I'd be more interested in variable input impedence.
>>
>> You could do it the easy way by just hanging a pot or switched fixed
>> resistors across the mic input terminals, or you could do it the
>> expensive (and more lifelike) way by using a tapped input transformer.
>
>Unfortunately, tapped input transformers are thin on the ground these days,
>and good ones are even thinner.

Lundahl has a very nice selection! And they aren't all that expensive
either.

I have been talking with Renco about doing some low ratio ones; they did
a marvelous job with some multitapped inductors for me. I can't say enough
good things about the Renco guys for inductors.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

In article <znr1100527200k@trad>, Mike Rivers > wrote:
>In article > writes:
>
>> The Hammond transformers I can get from AES, which also has the tubes and
>> the tube sockets. But resistors, switches, and miscellany all comes from
>> Digi-Key, the board comes from me, the case comes from Sescom or BUD, the
>> input transformers from Lundahl.
>
>Such is the life of a do-it-yourselfer. As someone pointed out here
>yesterday, he wants a Heathkit. Probably also wants complete assembly
>instructions in the package so he doesn't have to work from a magazine
>article, too.

Yes, that is what people in general seem to want. And they also seem to
be willing to pay for it, which is good.

>The practicality of this is a function of the popularity of the item.
>And the popularity of the item is a function of the bang for the buck.
>So if you can offer a lot of functionality for a low unassembled
>price, it might just be too popular to be able to handle the orders.
>It's a hard battle to win.

I dunno. I am still amazed at how well the Chinese mike boards are continuing
to sell, and how poorly the EQ modules have sold. I do not have any real
explanation about what makes a good project and what does not.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

In article <znr1100527200k@trad>, Mike Rivers > wrote:
>In article > writes:
>
>> The Hammond transformers I can get from AES, which also has the tubes and
>> the tube sockets. But resistors, switches, and miscellany all comes from
>> Digi-Key, the board comes from me, the case comes from Sescom or BUD, the
>> input transformers from Lundahl.
>
>Such is the life of a do-it-yourselfer. As someone pointed out here
>yesterday, he wants a Heathkit. Probably also wants complete assembly
>instructions in the package so he doesn't have to work from a magazine
>article, too.

Yes, that is what people in general seem to want. And they also seem to
be willing to pay for it, which is good.

>The practicality of this is a function of the popularity of the item.
>And the popularity of the item is a function of the bang for the buck.
>So if you can offer a lot of functionality for a low unassembled
>price, it might just be too popular to be able to handle the orders.
>It's a hard battle to win.

I dunno. I am still amazed at how well the Chinese mike boards are continuing
to sell, and how poorly the EQ modules have sold. I do not have any real
explanation about what makes a good project and what does not.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

In article >,
Bob Cain > wrote:
>
>
>Scott Dorsey wrote:
>> Bob Cain > wrote:
>>
>>>Wow! That certainly is the ticket for my app. Cascadable
>>>too for ganging. Only problem I see is the need for a PIC
>>>to convert an analog voltage from a gain pot to the digital
>>>gain control for the chips. PICs are cheap, but there would
>>>certainly be a learning curve and development investment for
>>>progamming one to do the job.
>>
>>
>> Skip the PIC and the pot. Use an optical encoder. It will take some glue
>> logic, but not all that much, and TTL is cheap.
>
>It's not pulse based. You send it serial frames with the
>gain and various other options coded as fields in the frame.

Right. So you have a shift register and a counter and the optical encoder
goes to the counter. You could use up and down buttons too and save a little
glue.

> At the least it would take a programmable logic part to
>assemble the frame and send it. A PIC would probably be the
>easiest approach in the end.

Why use a PIC when a clock and a shift register will do the job?
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

In article >,
Bob Cain > wrote:
>
>
>Scott Dorsey wrote:
>> Bob Cain > wrote:
>>
>>>Wow! That certainly is the ticket for my app. Cascadable
>>>too for ganging. Only problem I see is the need for a PIC
>>>to convert an analog voltage from a gain pot to the digital
>>>gain control for the chips. PICs are cheap, but there would
>>>certainly be a learning curve and development investment for
>>>progamming one to do the job.
>>
>>
>> Skip the PIC and the pot. Use an optical encoder. It will take some glue
>> logic, but not all that much, and TTL is cheap.
>
>It's not pulse based. You send it serial frames with the
>gain and various other options coded as fields in the frame.

Right. So you have a shift register and a counter and the optical encoder
goes to the counter. You could use up and down buttons too and save a little
glue.

> At the least it would take a programmable logic part to
>assemble the frame and send it. A PIC would probably be the
>easiest approach in the end.

Why use a PIC when a clock and a shift register will do the job?
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Richard Crowley]

"Scott Dorsey" wrote ...
> Why use a PIC when a clock and a shift register will do the job?

Fewer components? And in a few years discrete gates, latches,
shift registers may be hard to find. Of course, PICs seem to come
and go with fashion (and technological improvements) as well.

[Richard Crowley]

"Scott Dorsey" wrote ...
> Why use a PIC when a clock and a shift register will do the job?

Fewer components? And in a few years discrete gates, latches,
shift registers may be hard to find. Of course, PICs seem to come
and go with fashion (and technological improvements) as well.

[Richard Crowley]

"Scott Dorsey" wrote ...
> I am really suspicious of anything based on CMOS switching
> of any sort inside.

I was impressed that they claim to do the switching during
a zero-crossing to avoid switching ("zipper") noise.

[Richard Crowley]

"Scott Dorsey" wrote ...
> I am really suspicious of anything based on CMOS switching
> of any sort inside.

I was impressed that they claim to do the switching during
a zero-crossing to avoid switching ("zipper") noise.

[Scott Dorsey]

Richard Crowley > wrote:
>"Scott Dorsey" wrote ...
>> Why use a PIC when a clock and a shift register will do the job?
>
>Fewer components? And in a few years discrete gates, latches,
>shift registers may be hard to find. Of course, PICs seem to come
>and go with fashion (and technological improvements) as well.

That's the big worry. Microcontrollers in general change so quickly
that getting a new one to replace an old one is hard... and then you
have to program it. Same goes with FPGAS. Great for logic density,
not so good for long-term support. Also the programming process is
a pain to do at home without some fancy programming tools.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Richard Crowley > wrote:
>"Scott Dorsey" wrote ...
>> Why use a PIC when a clock and a shift register will do the job?
>
>Fewer components? And in a few years discrete gates, latches,
>shift registers may be hard to find. Of course, PICs seem to come
>and go with fashion (and technological improvements) as well.

That's the big worry. Microcontrollers in general change so quickly
that getting a new one to replace an old one is hard... and then you
have to program it. Same goes with FPGAS. Great for logic density,
not so good for long-term support. Also the programming process is
a pain to do at home without some fancy programming tools.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Richard Crowley]

"Scott Dorsey" > wrote ...
> Richard Crowley > wrote:
>>Fewer components? And in a few years discrete gates, latches,
>>shift registers may be hard to find. Of course, PICs seem to come
>>and go with fashion (and technological improvements) as well.
>
> That's the big worry. Microcontrollers in general change so quickly
> that getting a new one to replace an old one is hard... and then you
> have to program it. Same goes with FPGAS. Great for logic density,
> not so good for long-term support. Also the programming process is
> a pain to do at home without some fancy programming tools.

There have been some improvements there in the last few years. Some
very simple/inexpensive programming methods. Programming "hardware"
that amonuts to nothing more than wire and connectors, and freeware (or
cheapware). One of the more interesting sources is www.sparkfun.com

[Richard Crowley]

"Scott Dorsey" > wrote ...
> Richard Crowley > wrote:
>>Fewer components? And in a few years discrete gates, latches,
>>shift registers may be hard to find. Of course, PICs seem to come
>>and go with fashion (and technological improvements) as well.
>
> That's the big worry. Microcontrollers in general change so quickly
> that getting a new one to replace an old one is hard... and then you
> have to program it. Same goes with FPGAS. Great for logic density,
> not so good for long-term support. Also the programming process is
> a pain to do at home without some fancy programming tools.

There have been some improvements there in the last few years. Some
very simple/inexpensive programming methods. Programming "hardware"
that amonuts to nothing more than wire and connectors, and freeware (or
cheapware). One of the more interesting sources is www.sparkfun.com

[Paul Stamler]

"Scott Dorsey" > wrote in message
...

> I dunno. I am still amazed at how well the Chinese mike boards are
continuing
> to sell, and how poorly the EQ modules have sold. I do not have any real
> explanation about what makes a good project and what does not.

There's a *lot* of Chinese mikes out there, and the mod is a really cheap
way to get much better sound. The EQ's not so cheap, it's a
start-from-scratch project, and many people do all their EQing in software.
It's still a very nice design, though.

Peace,
Paul

[Paul Stamler]

"Scott Dorsey" > wrote in message
...

> I dunno. I am still amazed at how well the Chinese mike boards are
continuing
> to sell, and how poorly the EQ modules have sold. I do not have any real
> explanation about what makes a good project and what does not.

There's a *lot* of Chinese mikes out there, and the mod is a really cheap
way to get much better sound. The EQ's not so cheap, it's a
start-from-scratch project, and many people do all their EQing in software.
It's still a very nice design, though.

Peace,
Paul

[Mike Rivers]

In article > writes:

> >Such is the life of a do-it-yourselfer. As someone pointed out here
> >yesterday, he wants a Heathkit.

> Yes, that is what people in general seem to want. And they also seem to
> be willing to pay for it, which is good.

Yes, but a bit hard to understand today. Back where you couldn't buy a
decent Hi Fi amplifier or amateur transmitter in the local smut
emporium, Heathkits were a good alternative. I just don't see the
point to constructing someone else's design for, say, a mic preamp
unless it's something that's difficult to buy (a valid reason for
those in the hinterlands) or is unique. The sub-$100 pretty good
portable preamp to go with the Jukebox falls into the "I don't know of
anything like that" but the $250/channel transformer input mic preamp
isn't anything special.

> I am still amazed at how well the Chinese mike boards are continuing
> to sell, and how poorly the EQ modules have sold. I do not have any real
> explanation about what makes a good project and what does not.

It makes sense to me. You can buy a cheap mic, and for not to much
money and a coupe of hours of soldering, you can have a consierably
better mic (provided you like the basics of the mic to begin with).
But with all the plug-in equalizers out there, people aren't eager to
jump on to a hardware box, particularly one that doesn't have at least
a few rave reviews, like, for instance, the Speck, or the inexpensive
dbx sectretly designed by Bob Orban (if I got that right).


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> >Such is the life of a do-it-yourselfer. As someone pointed out here
> >yesterday, he wants a Heathkit.

> Yes, that is what people in general seem to want. And they also seem to
> be willing to pay for it, which is good.

Yes, but a bit hard to understand today. Back where you couldn't buy a
decent Hi Fi amplifier or amateur transmitter in the local smut
emporium, Heathkits were a good alternative. I just don't see the
point to constructing someone else's design for, say, a mic preamp
unless it's something that's difficult to buy (a valid reason for
those in the hinterlands) or is unique. The sub-$100 pretty good
portable preamp to go with the Jukebox falls into the "I don't know of
anything like that" but the $250/channel transformer input mic preamp
isn't anything special.

> I am still amazed at how well the Chinese mike boards are continuing
> to sell, and how poorly the EQ modules have sold. I do not have any real
> explanation about what makes a good project and what does not.

It makes sense to me. You can buy a cheap mic, and for not to much
money and a coupe of hours of soldering, you can have a consierably
better mic (provided you like the basics of the mic to begin with).
But with all the plug-in equalizers out there, people aren't eager to
jump on to a hardware box, particularly one that doesn't have at least
a few rave reviews, like, for instance, the Speck, or the inexpensive
dbx sectretly designed by Bob Orban (if I got that right).


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Magnus Jans?n]

(Scott Dorsey) wrote in message >...

> I dunno. I am still amazed at how well the Chinese mike boards are continuing
> to sell, and how poorly the EQ modules have sold. I do not have any real
> explanation about what makes a good project and what does not.
> --scott

Is it so strange?

Everyone that reads Recording uses a microphone every single day. Most
use several every day. Hobby recordists, radio people, multimedia
people, studio people - all of those can and will use a decent LD
condenser. Most of them can use several.

But how many of them have a pressing need for an outboard EQ? I'd bet
that a lot of the readers are all DAW these days except for
transducers and transducer amplification. So connecting things up to
send channel data through an outboard unit is a cumbersome option for
most.
The live people, who could use an analog unit, would probably be more
interested in in a surgical EQ(I know I am in my limited live work).
So when you say right there in the intro of the article that it's NOT
a surgical EQ... well.
This leaves the recording people who still mix on analog. A sizable
group no doubt, but nowhere near the bulk of readers they were a mere
6 years ago.

And then there is the whole case thing, but that's been covered.

On a completely different note: Just out of curiosity Mr Dorsey, what
would set your limbo tube preamp project apart from the Hamptone kit?

/Magnus

[Magnus Jans?n]

(Scott Dorsey) wrote in message >...

> I dunno. I am still amazed at how well the Chinese mike boards are continuing
> to sell, and how poorly the EQ modules have sold. I do not have any real
> explanation about what makes a good project and what does not.
> --scott

Is it so strange?

Everyone that reads Recording uses a microphone every single day. Most
use several every day. Hobby recordists, radio people, multimedia
people, studio people - all of those can and will use a decent LD
condenser. Most of them can use several.

But how many of them have a pressing need for an outboard EQ? I'd bet
that a lot of the readers are all DAW these days except for
transducers and transducer amplification. So connecting things up to
send channel data through an outboard unit is a cumbersome option for
most.
The live people, who could use an analog unit, would probably be more
interested in in a surgical EQ(I know I am in my limited live work).
So when you say right there in the intro of the article that it's NOT
a surgical EQ... well.
This leaves the recording people who still mix on analog. A sizable
group no doubt, but nowhere near the bulk of readers they were a mere
6 years ago.

And then there is the whole case thing, but that's been covered.

On a completely different note: Just out of curiosity Mr Dorsey, what
would set your limbo tube preamp project apart from the Hamptone kit?

/Magnus

[Scott Dorsey]

Magnus Jans?n > wrote:
>
>On a completely different note: Just out of curiosity Mr Dorsey, what
>would set your limbo tube preamp project apart from the Hamptone kit?

I don't know, having not actually listened to the Hamptone kit. But one
big advantage is that you can get the Hamptone kit...
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Magnus Jans?n > wrote:
>
>On a completely different note: Just out of curiosity Mr Dorsey, what
>would set your limbo tube preamp project apart from the Hamptone kit?

I don't know, having not actually listened to the Hamptone kit. But one
big advantage is that you can get the Hamptone kit...
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Peter B.]

(Mike Rivers) wrote in message news:<znr1100392084k@trad>...
> In article <2004111313443316807%coxg@usfcaedu> writes:

> That's OK if you're doing it just for yourself and don't have a lot of
> pride. But if you have a client coming in and you plug a mic into a
> ragged looking box, what's he going to think?


I kind of like the DIY look. Black hex cap screws look good against a
hand soldered copper/brass chassis. As long as everything is square
and the holes are positioned within +/- .005" it looks pretty good.
Dymo metal tape looks good to me. Some oversize knobs and handles will
complete the look.

As long as a the device looks scary in a organized way I don't think
the client would mind. It has 'secret weapon' appeal.

Peter

[Peter B.]

(Mike Rivers) wrote in message news:<znr1100392084k@trad>...
> In article <2004111313443316807%coxg@usfcaedu> writes:

> That's OK if you're doing it just for yourself and don't have a lot of
> pride. But if you have a client coming in and you plug a mic into a
> ragged looking box, what's he going to think?


I kind of like the DIY look. Black hex cap screws look good against a
hand soldered copper/brass chassis. As long as everything is square
and the holes are positioned within +/- .005" it looks pretty good.
Dymo metal tape looks good to me. Some oversize knobs and handles will
complete the look.

As long as a the device looks scary in a organized way I don't think
the client would mind. It has 'secret weapon' appeal.

Peter

[Kurt Albershardt]

$410 sounds about right for a $200+ item c.1984 or so.

I don't seem them on p. 2123 -- do you have an item number?






Dan Kennedy wrote:
> Greenlee makes 'em, and they are more like $410 in my McMaster-Carr
> catalog, but just below them is another brand that makes you drill
> 3 holes, not just one for $189 to $239 depending on size.
>
>
>
> Kurt Albershardt wrote:
>
>> Scott Dorsey wrote:
>>
>>> Kurt Albershardt > wrote:
>>>
>>>> Scott Dorsey wrote:
>>>>
>>>>
>>>>> I did not know that there were ANY hand punches that will do all
>>>>> three holes
>>>>> in one operation! If you know of one, I would really like to
>>>>> know. I have
>>>>> used a small hydraulic press with custom tooling, a combination
>>>>> that cost a
>>>>> lot more than $200 and was not convenient to take into the field.
>>>>> A hand punch
>>>>> that would do all three holes would be wonderful for field
>>>>> modification work.
>>>>
>>>>
>>>>
>>>> At a place I worked in Hollywood, we used to have a set (one for
>>>> each connector sex.) It was a single hole with keyways (notches) for
>>>> the mounting screws. I don't know who made them.
>>>
>>>
>>>
>>>
>>> That is exactly what I want! Where do I get them? A couple hundred
>>> bucks each is doable if they last.
>>
>>
>>
>> They were $200+ in 1984, and I still don't know where they came from.
>>
>>
>

[Kurt Albershardt]

$410 sounds about right for a $200+ item c.1984 or so.

I don't seem them on p. 2123 -- do you have an item number?






Dan Kennedy wrote:
> Greenlee makes 'em, and they are more like $410 in my McMaster-Carr
> catalog, but just below them is another brand that makes you drill
> 3 holes, not just one for $189 to $239 depending on size.
>
>
>
> Kurt Albershardt wrote:
>
>> Scott Dorsey wrote:
>>
>>> Kurt Albershardt > wrote:
>>>
>>>> Scott Dorsey wrote:
>>>>
>>>>
>>>>> I did not know that there were ANY hand punches that will do all
>>>>> three holes
>>>>> in one operation! If you know of one, I would really like to
>>>>> know. I have
>>>>> used a small hydraulic press with custom tooling, a combination
>>>>> that cost a
>>>>> lot more than $200 and was not convenient to take into the field.
>>>>> A hand punch
>>>>> that would do all three holes would be wonderful for field
>>>>> modification work.
>>>>
>>>>
>>>>
>>>> At a place I worked in Hollywood, we used to have a set (one for
>>>> each connector sex.) It was a single hole with keyways (notches) for
>>>> the mounting screws. I don't know who made them.
>>>
>>>
>>>
>>>
>>> That is exactly what I want! Where do I get them? A couple hundred
>>> bucks each is doable if they last.
>>
>>
>>
>> They were $200+ in 1984, and I still don't know where they came from.
>>
>>
>

[Ralph Barone]

In article <znr1100391373k@trad>, (Mike Rivers)
wrote:

> In article >
> writes:
>
> > In this design, you can leave out whatever you don't want;
> > leaving out the high-pass filter will save $5-something per channel (the
> > price of the switch), leaving out the balanced outputs will save about $16
> > per channel. By leaving the phantom on all the time (global on/off
> > switching
> > only), you save another $5-something. So a stripped-down version would cost
> > about $148 a channel.
>
> Mr. Marketing here . . .
>
> How about presenting it as a two-channel preamp which, I suspect, is
> more in demand than an eight-channel preamp. Make a two-channel board
> with pads to mount components for phantom powering, the high-pass
> filter, and the additional components for the balanced output. Let the
> user decide what extra features he wants to add for more flexibility
> rather than what features he wants to leave out to save a few bucks.
> The power supply will handle up to eight channels worth of boards, so
> the preamp can grow as the users' needs grow.
>
> The chassis, panel, and case will remain a stumbling block for many,
> however.
>
> --
> I'm really Mike Rivers )
> However, until the spam goes away or Hell freezes over,
> lots of IP addresses are blocked from this system. If
> you e-mail me and it bounces, use your secret decoder ring
> and reach me here: double-m-eleven-double-zero at yahoo

We have discovered that laser engravers are marvelous beasts. Draw your
front panel up in Visio, bring the file to your local trophy shop, and
they will burn it onto a lamacoid sheet for you. Any shape you can
draw, they can cut it for you. For low-budget (albeit, non-metallic)
front panels, you can't beat that for price and convenience.

[Ralph Barone]

In article <znr1100391373k@trad>, (Mike Rivers)
wrote:

> In article >
> writes:
>
> > In this design, you can leave out whatever you don't want;
> > leaving out the high-pass filter will save $5-something per channel (the
> > price of the switch), leaving out the balanced outputs will save about $16
> > per channel. By leaving the phantom on all the time (global on/off
> > switching
> > only), you save another $5-something. So a stripped-down version would cost
> > about $148 a channel.
>
> Mr. Marketing here . . .
>
> How about presenting it as a two-channel preamp which, I suspect, is
> more in demand than an eight-channel preamp. Make a two-channel board
> with pads to mount components for phantom powering, the high-pass
> filter, and the additional components for the balanced output. Let the
> user decide what extra features he wants to add for more flexibility
> rather than what features he wants to leave out to save a few bucks.
> The power supply will handle up to eight channels worth of boards, so
> the preamp can grow as the users' needs grow.
>
> The chassis, panel, and case will remain a stumbling block for many,
> however.
>
> --
> I'm really Mike Rivers )
> However, until the spam goes away or Hell freezes over,
> lots of IP addresses are blocked from this system. If
> you e-mail me and it bounces, use your secret decoder ring
> and reach me here: double-m-eleven-double-zero at yahoo

We have discovered that laser engravers are marvelous beasts. Draw your
front panel up in Visio, bring the file to your local trophy shop, and
they will burn it onto a lamacoid sheet for you. Any shape you can
draw, they can cut it for you. For low-budget (albeit, non-metallic)
front panels, you can't beat that for price and convenience.

[Bob Cain]

Scott Dorsey wrote:

> Why use a PIC when a clock and a shift register will do the job?

You'd have an asynchronous counter being grabbed by a
synchronous shift register. I guess you could detect
changes in the gain counter, delay that detection to let all
the bits settle and use the detector to clock the count into
a shift register and to start a counter controled chip
select synchronized with the shift clock but we're getting
into more logic here than a six or eight pin PIC.

If you are using a pulse shaft encoder then you have the
problem that on power up you don't know where the knob is.
If you used a coded shaft encoder (from the dept. of
redundancy dept.) you could solve that but you would still
need to synchronize. Gray codes would make this all a bit
easier but...

I think an analog voltage divider pot into a PIC with a
small, slow, integrated A/D would be easier, smaller and
more convenient. I absolutely hate up/down buttons for gain
control.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

[Bob Cain]

Scott Dorsey wrote:

> Why use a PIC when a clock and a shift register will do the job?

You'd have an asynchronous counter being grabbed by a
synchronous shift register. I guess you could detect
changes in the gain counter, delay that detection to let all
the bits settle and use the detector to clock the count into
a shift register and to start a counter controled chip
select synchronized with the shift clock but we're getting
into more logic here than a six or eight pin PIC.

If you are using a pulse shaft encoder then you have the
problem that on power up you don't know where the knob is.
If you used a coded shaft encoder (from the dept. of
redundancy dept.) you could solve that but you would still
need to synchronize. Gray codes would make this all a bit
easier but...

I think an analog voltage divider pot into a PIC with a
small, slow, integrated A/D would be easier, smaller and
more convenient. I absolutely hate up/down buttons for gain
control.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

[Bob Cain]

Scott Dorsey wrote:

> That's the big worry. Microcontrollers in general change so quickly
> that getting a new one to replace an old one is hard...

Only design in parts from a trusted manufacturer with a good
long track record of continuing production of old designs.
First thing you learn on the job as a dev. engineer and one
of the most important policing functions of a first line
hdw. engineering manager.

> and then you
> have to program it. Same goes with FPGAS. Great for logic density,
> not so good for long-term support. Also the programming process is
> a pain to do at home without some fancy programming tools.

I gave this a brief look and it isn't that bad at all. For
PIC's the software is a practically a giveaway and
development can be done with a serial link. It looks like
they've gone all out to entice system designers to build
these things in (unlike the foolish DSP chip vendors who
insist on making good money on their dev systems.)


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

[Bob Cain]

Scott Dorsey wrote:

> That's the big worry. Microcontrollers in general change so quickly
> that getting a new one to replace an old one is hard...

Only design in parts from a trusted manufacturer with a good
long track record of continuing production of old designs.
First thing you learn on the job as a dev. engineer and one
of the most important policing functions of a first line
hdw. engineering manager.

> and then you
> have to program it. Same goes with FPGAS. Great for logic density,
> not so good for long-term support. Also the programming process is
> a pain to do at home without some fancy programming tools.

I gave this a brief look and it isn't that bad at all. For
PIC's the software is a practically a giveaway and
development can be done with a serial link. It looks like
they've gone all out to entice system designers to build
these things in (unlike the foolish DSP chip vendors who
insist on making good money on their dev systems.)


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

[Mike Rivers]

In article > writes:

> I kind of like the DIY look. Black hex cap screws look good against a
> hand soldered copper/brass chassis. As long as everything is square
> and the holes are positioned within +/- .005" it looks pretty good.

I'll agree with that.

> Dymo metal tape looks good to me. Some oversize knobs and handles will
> complete the look.

I don't agree with that. Dymo tape to me symbolizes an experimental or
unfinished project. That's not what I want to trust my sound to.

> As long as a the device looks scary in a organized way I don't think
> the client would mind. It has 'secret weapon' appeal.

I guess it all depends on the client. When I had a remote recording
truck, some of the best advice I got was to keep it clean and neat,
put doors on the front of the Ampex multitrack recorder, and have a
nice looking mic splitter. A house engineer who's responsible for the
club audience isn't going to feel very good about plugging his mics
into a ratty looking box with tape labels on it. But hand him a nicely
finished box with engraving and he won't worry.

Same goes with gear in the studio rack. If you're a funky studio and
you're known for that, then there's no problem with funky looking
gear. But if you work with clients who expect a professional
atmosphere, you have to finesse the funky stuff, not use it as a
matter of course.


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> I kind of like the DIY look. Black hex cap screws look good against a
> hand soldered copper/brass chassis. As long as everything is square
> and the holes are positioned within +/- .005" it looks pretty good.

I'll agree with that.

> Dymo metal tape looks good to me. Some oversize knobs and handles will
> complete the look.

I don't agree with that. Dymo tape to me symbolizes an experimental or
unfinished project. That's not what I want to trust my sound to.

> As long as a the device looks scary in a organized way I don't think
> the client would mind. It has 'secret weapon' appeal.

I guess it all depends on the client. When I had a remote recording
truck, some of the best advice I got was to keep it clean and neat,
put doors on the front of the Ampex multitrack recorder, and have a
nice looking mic splitter. A house engineer who's responsible for the
club audience isn't going to feel very good about plugging his mics
into a ratty looking box with tape labels on it. But hand him a nicely
finished box with engraving and he won't worry.

Same goes with gear in the studio rack. If you're a funky studio and
you're known for that, then there's no problem with funky looking
gear. But if you work with clients who expect a professional
atmosphere, you have to finesse the funky stuff, not use it as a
matter of course.


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[John O]

>> explaining what each thing does, why this is good design practice etc.
>> So that at the end of assembling I may have learnt something. That's
>> ALL I want.
>
> Well there is some benefit to that. Put it together and you'll have a
> better idea of how to fix it when it breaks.

True, if you assume the builder has some knowledge of the circuits in the
first place. What ended up happening at Heathkit was that kitbuilders didn't
want to learn the circuits and troubleshoot them. They wanted US to fix
their soldering and construction mistakes. (and yes it's true...75% of the
kits simply had soldering problems...)

-John O

[John O]

>> explaining what each thing does, why this is good design practice etc.
>> So that at the end of assembling I may have learnt something. That's
>> ALL I want.
>
> Well there is some benefit to that. Put it together and you'll have a
> better idea of how to fix it when it breaks.

True, if you assume the builder has some knowledge of the circuits in the
first place. What ended up happening at Heathkit was that kitbuilders didn't
want to learn the circuits and troubleshoot them. They wanted US to fix
their soldering and construction mistakes. (and yes it's true...75% of the
kits simply had soldering problems...)

-John O

[John O]

>
> The practicality of this is a function of the popularity of the item.
> And the popularity of the item is a function of the bang for the buck.
> So if you can offer a lot of functionality for a low unassembled
> price, it might just be too popular to be able to handle the orders.
> It's a hard battle to win.


From the company's viewpoint, the kit needs to make as much margin as the
assembled unit. Remove the assembly labor, add the assembly manual writing,
packaging, and back-end tech support and service, and how are the numbers
now? Usually, it's a losing deal unless assembly labor costs are quite high.
Tech support is the killer. If assembly is Pacific Rim, then it never works
because assembly is a minor piece of the cost.

If the kits were only sold to folks like you guys watching this thread, it
would be great. Unfortunately, people with zero experience or knowledge or
patience buy the kits, and they get PO'd when they make mistakes. Fixing the
problems makes the total cost meet or exceed the assembled price, and now
they're even more PO'd.

Heathkit still considers making kits to this day, but these are large
obstacles.

-John O

[John O]

>
> The practicality of this is a function of the popularity of the item.
> And the popularity of the item is a function of the bang for the buck.
> So if you can offer a lot of functionality for a low unassembled
> price, it might just be too popular to be able to handle the orders.
> It's a hard battle to win.


From the company's viewpoint, the kit needs to make as much margin as the
assembled unit. Remove the assembly labor, add the assembly manual writing,
packaging, and back-end tech support and service, and how are the numbers
now? Usually, it's a losing deal unless assembly labor costs are quite high.
Tech support is the killer. If assembly is Pacific Rim, then it never works
because assembly is a minor piece of the cost.

If the kits were only sold to folks like you guys watching this thread, it
would be great. Unfortunately, people with zero experience or knowledge or
patience buy the kits, and they get PO'd when they make mistakes. Fixing the
problems makes the total cost meet or exceed the assembled price, and now
they're even more PO'd.

Heathkit still considers making kits to this day, but these are large
obstacles.

-John O

[Scott Dorsey]

Ralph Barone > wrote:
>
>We have discovered that laser engravers are marvelous beasts. Draw your
>front panel up in Visio, bring the file to your local trophy shop, and
>they will burn it onto a lamacoid sheet for you. Any shape you can
>draw, they can cut it for you. For low-budget (albeit, non-metallic)
>front panels, you can't beat that for price and convenience.

Our neighborhood trophy shop can not only do laser engraving onto plastic
sheets, but they can also do laser engraving onto black anodized aluminum.
This produces really wonderfully crisp-looking panels. It's a bit more
expensive than deep engraving, and I do like the way deep engraving feels,
but it's possible to do very accurate positioning and work from computer
layouts or camera-ready copy. This is a big deal if you have logos you want
on there, or you want to put a lot of numbers around the edge of a circle
at particular positions for an indicator knob.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Ralph Barone > wrote:
>
>We have discovered that laser engravers are marvelous beasts. Draw your
>front panel up in Visio, bring the file to your local trophy shop, and
>they will burn it onto a lamacoid sheet for you. Any shape you can
>draw, they can cut it for you. For low-budget (albeit, non-metallic)
>front panels, you can't beat that for price and convenience.

Our neighborhood trophy shop can not only do laser engraving onto plastic
sheets, but they can also do laser engraving onto black anodized aluminum.
This produces really wonderfully crisp-looking panels. It's a bit more
expensive than deep engraving, and I do like the way deep engraving feels,
but it's possible to do very accurate positioning and work from computer
layouts or camera-ready copy. This is a big deal if you have logos you want
on there, or you want to put a lot of numbers around the edge of a circle
at particular positions for an indicator knob.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Bob Cain > wrote:
>Scott Dorsey wrote:
>
>> Why use a PIC when a clock and a shift register will do the job?
>
>You'd have an asynchronous counter being grabbed by a
>synchronous shift register. I guess you could detect
>changes in the gain counter, delay that detection to let all
>the bits settle and use the detector to clock the count into
>a shift register and to start a counter controled chip
>select synchronized with the shift clock but we're getting
>into more logic here than a six or eight pin PIC.

That's why you have latches on the outputs of most of the shift register
chips.

>If you are using a pulse shaft encoder then you have the
>problem that on power up you don't know where the knob is.
>If you used a coded shaft encoder (from the dept. of
>redundancy dept.) you could solve that but you would still
>need to synchronize. Gray codes would make this all a bit
>easier but...

Right. You have zero the thing out on reset and then just live with that.

>I think an analog voltage divider pot into a PIC with a
>small, slow, integrated A/D would be easier, smaller and
>more convenient. I absolutely hate up/down buttons for gain
>control.

I agree about the up/down stuff. But then, you know, I like just
plain variable resistors in the audio path, personally.

You know that Digi-Key used to carry some of the Panasonic pots with
a DC motor attached. Alps makes some of those too. They seem a much
more elegant way of doing remote volume control than a gadget with a bunch
of CMOS switches and ladder resistors.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Bob Cain > wrote:
>Scott Dorsey wrote:
>
>> Why use a PIC when a clock and a shift register will do the job?
>
>You'd have an asynchronous counter being grabbed by a
>synchronous shift register. I guess you could detect
>changes in the gain counter, delay that detection to let all
>the bits settle and use the detector to clock the count into
>a shift register and to start a counter controled chip
>select synchronized with the shift clock but we're getting
>into more logic here than a six or eight pin PIC.

That's why you have latches on the outputs of most of the shift register
chips.

>If you are using a pulse shaft encoder then you have the
>problem that on power up you don't know where the knob is.
>If you used a coded shaft encoder (from the dept. of
>redundancy dept.) you could solve that but you would still
>need to synchronize. Gray codes would make this all a bit
>easier but...

Right. You have zero the thing out on reset and then just live with that.

>I think an analog voltage divider pot into a PIC with a
>small, slow, integrated A/D would be easier, smaller and
>more convenient. I absolutely hate up/down buttons for gain
>control.

I agree about the up/down stuff. But then, you know, I like just
plain variable resistors in the audio path, personally.

You know that Digi-Key used to carry some of the Panasonic pots with
a DC motor attached. Alps makes some of those too. They seem a much
more elegant way of doing remote volume control than a gadget with a bunch
of CMOS switches and ladder resistors.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Michael R. Kesti]

Mike Rivers wrote:

>In article > writes:
>
>> > Check out the Burr-Brown PGA2500.
>
>> Wow! That certainly is the ticket for my app. Cascadable
>> too for ganging. Only problem I see is the need for a PIC
>> to convert an analog voltage from a gain pot to the digital
>> gain control for the chips. PICs are cheap, but there would
>> certainly be a learning curve and development investment for
>> progamming one to do the job.
>
>I don't know what kind of digital input it wants for gain control.

The PGA2500's parameters, including gain, are controlled by the serial
receipt of 16 bits of data. It neither knows nor cares about the source
of that data and they could as well be a fixed value, a digital conversion
of an analog pot, a shaft encoder, a Windows(TM) dialog, or what have you.

I
>was thinking of an encoder with a knob, but I'll bet that being an
>electro-mechanical device it would be a whole lot more expensive than
>something all digital (assuming the programming came free <g>).

That sounds about right.

--
================================================== ======================
Michael Kesti | "And like, one and one don't make
| two, one and one make one."
| - The Who, Bargain

[Michael R. Kesti]

Mike Rivers wrote:

>In article > writes:
>
>> > Check out the Burr-Brown PGA2500.
>
>> Wow! That certainly is the ticket for my app. Cascadable
>> too for ganging. Only problem I see is the need for a PIC
>> to convert an analog voltage from a gain pot to the digital
>> gain control for the chips. PICs are cheap, but there would
>> certainly be a learning curve and development investment for
>> progamming one to do the job.
>
>I don't know what kind of digital input it wants for gain control.

The PGA2500's parameters, including gain, are controlled by the serial
receipt of 16 bits of data. It neither knows nor cares about the source
of that data and they could as well be a fixed value, a digital conversion
of an analog pot, a shaft encoder, a Windows(TM) dialog, or what have you.

I
>was thinking of an encoder with a knob, but I'll bet that being an
>electro-mechanical device it would be a whole lot more expensive than
>something all digital (assuming the programming came free <g>).

That sounds about right.

--
================================================== ======================
Michael Kesti | "And like, one and one don't make
| two, one and one make one."
| - The Who, Bargain

[Richard Crowley]

"Scott Dorsey" wrote ...
> You know that Digi-Key used to carry some of the
> Panasonic pots with a DC motor attached. Alps
> makes some of those too.

Still available at a few surplus outlets, but no choice of
pot value, of course.

> They seem a much more elegant way of doing remote
> volume control than a gadget with a bunch of CMOS
> switches and ladder resistors.

But most of those circuits require reverse-log tapers to
give a resonably linear control contour. And it is getting
harder to even find decent forward-log taper pots these
days.

Note that the chip waits for a program waveform zero-
crossing to change the gain (to avoid "zipper" noise).
I thought that was pretty nifty.

[Richard Crowley]

"Scott Dorsey" wrote ...
> You know that Digi-Key used to carry some of the
> Panasonic pots with a DC motor attached. Alps
> makes some of those too.

Still available at a few surplus outlets, but no choice of
pot value, of course.

> They seem a much more elegant way of doing remote
> volume control than a gadget with a bunch of CMOS
> switches and ladder resistors.

But most of those circuits require reverse-log tapers to
give a resonably linear control contour. And it is getting
harder to even find decent forward-log taper pots these
days.

Note that the chip waits for a program waveform zero-
crossing to change the gain (to avoid "zipper" noise).
I thought that was pretty nifty.

[Mike Rivers]

In article > writes:

> What ended up happening at Heathkit was that kitbuilders didn't
> want to learn the circuits and troubleshoot them. They wanted US to fix
> their soldering and construction mistakes. (and yes it's true...75% of the
> kits simply had soldering problems...)

Many times we see posts here from people who say "I don't know much
about soddering [sic] but I want to make my own cables. Can someone
point me to a good web sight [sic] to buy wire and connectors? All the
places I've found are too expensive."

But in the early days of Heathkits, I suspect that a good percentage
of the purchasers were electronic hobbyists who were there for the
learning experience. The old Heathkit manuals had a section on making
good solder joints and how to inspect and test them. I suppose that
was ignored by many customers, but the information was there and
reasonably accurate for those who took the time to learn what they
were doing. Also, with point-to-point wiring, tube sockets, and
terminal strips, it was fairly easy to make decent soldered
connections if you put a little care into it. But today too many
people try to solder ICs on to a dense board using the same iron they
used when they built their Heathkits 40 years ago.


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> What ended up happening at Heathkit was that kitbuilders didn't
> want to learn the circuits and troubleshoot them. They wanted US to fix
> their soldering and construction mistakes. (and yes it's true...75% of the
> kits simply had soldering problems...)

Many times we see posts here from people who say "I don't know much
about soddering [sic] but I want to make my own cables. Can someone
point me to a good web sight [sic] to buy wire and connectors? All the
places I've found are too expensive."

But in the early days of Heathkits, I suspect that a good percentage
of the purchasers were electronic hobbyists who were there for the
learning experience. The old Heathkit manuals had a section on making
good solder joints and how to inspect and test them. I suppose that
was ignored by many customers, but the information was there and
reasonably accurate for those who took the time to learn what they
were doing. Also, with point-to-point wiring, tube sockets, and
terminal strips, it was fairly easy to make decent soldered
connections if you put a little care into it. But today too many
people try to solder ICs on to a dense board using the same iron they
used when they built their Heathkits 40 years ago.


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[GKB]

Hey Paul , i'd be happy to order a couple & prepay [ paypal would be
easy ]
can you reply to me when you have a moment as i don't know whether my email
makes it to you personal address .

thank regards Greg



"Paul Stamler" > wrote in message
...
> Hi folks:
>
> Let me launch a trial balloon here. Is this a DIY project that appeals to
> you?
>
> It's a microphone preamp, solid state, transformer in (Jensen),
> transformerless balanced +4dBu out with a separate -10dBV unbalanced out.
IC
> based, up to 8 channels in a 2U case, plus separate power pack. Phantom on
> all channels, 100Hz rolloff selectable on all channels, otherwise no EQ.
> Designed to be comparable to the Sytek in price, performance and feature
> set, but with transformer-coupled inputs. All parts obtainable (to North
> Americans, at any rate) from Digi-Key and Allied Electronics, except for
the
> transformers, which come directly from Jensen. On-card regulation. Like
the
> Sytek, there are some optional choices in what ICs you use.
>
> Approximate costs are as follows. These include everything except the
cases,
> which are up to you. At the moment I'm assuming the PC boards would cost
> $25.00 / ea.; that's the biggest unknown in the equation. I can't really
> fill that in until I design the boards, and I'm not gonna do that until I
> find out whether anybody's interested. (Also, of course, price of the
boards
> will vary depending on how many I order.) There are options which will
raise
> the price, and some that will lower it, but this is the basic design.
>
> Each input channel: $220.00
>
> Power Supply: $120.00
>
> So a 4-channel unit would cost almost exactly $1k, not counting boxes. An
> 8-channel would be $1880, ditto. I'd make my slice selling the PC boards
and
> writing it up for the magazines.
>
> Any interest?
>
> Peace,
> Paul
>
>

[GKB]

Hey Paul , i'd be happy to order a couple & prepay [ paypal would be
easy ]
can you reply to me when you have a moment as i don't know whether my email
makes it to you personal address .

thank regards Greg



"Paul Stamler" > wrote in message
...
> Hi folks:
>
> Let me launch a trial balloon here. Is this a DIY project that appeals to
> you?
>
> It's a microphone preamp, solid state, transformer in (Jensen),
> transformerless balanced +4dBu out with a separate -10dBV unbalanced out.
IC
> based, up to 8 channels in a 2U case, plus separate power pack. Phantom on
> all channels, 100Hz rolloff selectable on all channels, otherwise no EQ.
> Designed to be comparable to the Sytek in price, performance and feature
> set, but with transformer-coupled inputs. All parts obtainable (to North
> Americans, at any rate) from Digi-Key and Allied Electronics, except for
the
> transformers, which come directly from Jensen. On-card regulation. Like
the
> Sytek, there are some optional choices in what ICs you use.
>
> Approximate costs are as follows. These include everything except the
cases,
> which are up to you. At the moment I'm assuming the PC boards would cost
> $25.00 / ea.; that's the biggest unknown in the equation. I can't really
> fill that in until I design the boards, and I'm not gonna do that until I
> find out whether anybody's interested. (Also, of course, price of the
boards
> will vary depending on how many I order.) There are options which will
raise
> the price, and some that will lower it, but this is the basic design.
>
> Each input channel: $220.00
>
> Power Supply: $120.00
>
> So a 4-channel unit would cost almost exactly $1k, not counting boxes. An
> 8-channel would be $1880, ditto. I'd make my slice selling the PC boards
and
> writing it up for the magazines.
>
> Any interest?
>
> Peace,
> Paul
>
>

[Mike Rivers]

In article > writes:

> You know that Digi-Key used to carry some of the Panasonic pots with
> a DC motor attached. Alps makes some of those too. They seem a much
> more elegant way of doing remote volume control than a gadget with a bunch
> of CMOS switches and ladder resistors.

The matter at hand wasn't remote volume control, it was to have a
single control for two channels. Of course you could do that with
motorized pots, but that's going to push the size, weight, and price
part of the "marketing requirements"

--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> You know that Digi-Key used to carry some of the Panasonic pots with
> a DC motor attached. Alps makes some of those too. They seem a much
> more elegant way of doing remote volume control than a gadget with a bunch
> of CMOS switches and ladder resistors.

The matter at hand wasn't remote volume control, it was to have a
single control for two channels. Of course you could do that with
motorized pots, but that's going to push the size, weight, and price
part of the "marketing requirements"

--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Scott Dorsey]

In article <znr1100624425k@trad>, Mike Rivers > wrote:
>
>In article > writes:
>
>> You know that Digi-Key used to carry some of the Panasonic pots with
>> a DC motor attached. Alps makes some of those too. They seem a much
>> more elegant way of doing remote volume control than a gadget with a bunch
>> of CMOS switches and ladder resistors.
>
>The matter at hand wasn't remote volume control, it was to have a
>single control for two channels. Of course you could do that with
>motorized pots, but that's going to push the size, weight, and price
>part of the "marketing requirements"

Single control for two channels? Sounds like an application for DUAL LOG
TAPER to me.

Yes, I know electronic gain control devices are cheaper than dual pots that
track well. THAT's the depressing part.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

In article <znr1100624425k@trad>, Mike Rivers > wrote:
>
>In article > writes:
>
>> You know that Digi-Key used to carry some of the Panasonic pots with
>> a DC motor attached. Alps makes some of those too. They seem a much
>> more elegant way of doing remote volume control than a gadget with a bunch
>> of CMOS switches and ladder resistors.
>
>The matter at hand wasn't remote volume control, it was to have a
>single control for two channels. Of course you could do that with
>motorized pots, but that's going to push the size, weight, and price
>part of the "marketing requirements"

Single control for two channels? Sounds like an application for DUAL LOG
TAPER to me.

Yes, I know electronic gain control devices are cheaper than dual pots that
track well. THAT's the depressing part.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Mike Rivers]

In article > writes:

> Single control for two channels? Sounds like an application for DUAL LOG
> TAPER to me.

Naw, he wants it both ways - individual control or with both channels
tracking.

> Yes, I know electronic gain control devices are cheaper than dual pots that
> track well. THAT's the depressing part.

That's progress, to some anyway.

--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> Single control for two channels? Sounds like an application for DUAL LOG
> TAPER to me.

Naw, he wants it both ways - individual control or with both channels
tracking.

> Yes, I know electronic gain control devices are cheaper than dual pots that
> track well. THAT's the depressing part.

That's progress, to some anyway.

--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Kurt Albershardt]

Scott Dorsey wrote:
>
> Single control for two channels? Sounds like an application for DUAL LOG
> TAPER to me.
>
> Yes, I know electronic gain control devices are cheaper than dual pots that
> track well. THAT's the depressing part.


There used to be a surplus place in LA that sold nothing but resistors. Somewhere on Pico or Venice just east of Fairfax maybe? Anyway they had a whole shop full of military & high grade commercial stuff. I used to buy dummy load stuff from them and they had a TON of pots.

Of course this was 15 years ago...

[Kurt Albershardt]

Scott Dorsey wrote:
>
> Single control for two channels? Sounds like an application for DUAL LOG
> TAPER to me.
>
> Yes, I know electronic gain control devices are cheaper than dual pots that
> track well. THAT's the depressing part.


There used to be a surplus place in LA that sold nothing but resistors. Somewhere on Pico or Venice just east of Fairfax maybe? Anyway they had a whole shop full of military & high grade commercial stuff. I used to buy dummy load stuff from them and they had a TON of pots.

Of course this was 15 years ago...

[Scott Dorsey]

In article <znr1100646634k@trad>, Mike Rivers > wrote:
>In article > writes:
>
>> Single control for two channels? Sounds like an application for DUAL LOG
>> TAPER to me.
>
>Naw, he wants it both ways - individual control or with both channels
>tracking.

DUAL CONCENTRIC LOG TAPER.

I don't know of anybody still making these, though.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

In article <znr1100646634k@trad>, Mike Rivers > wrote:
>In article > writes:
>
>> Single control for two channels? Sounds like an application for DUAL LOG
>> TAPER to me.
>
>Naw, he wants it both ways - individual control or with both channels
>tracking.

DUAL CONCENTRIC LOG TAPER.

I don't know of anybody still making these, though.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Arny Krueger]

"Scott Dorsey" > wrote in message

> In article <znr1100624425k@trad>, Mike Rivers >
> wrote:
>>
>> In article > writes:
>>
>>> You know that Digi-Key used to carry some of the Panasonic pots with
>>> a DC motor attached. Alps makes some of those too. They seem a
>>> much more elegant way of doing remote volume control than a gadget
>>> with a bunch of CMOS switches and ladder resistors.
>>
>> The matter at hand wasn't remote volume control, it was to have a
>> single control for two channels. Of course you could do that with
>> motorized pots, but that's going to push the size, weight, and price
>> part of the "marketing requirements"
>
> Single control for two channels? Sounds like an application for DUAL
> LOG TAPER to me.
>
> Yes, I know electronic gain control devices are cheaper than dual
> pots that track well. THAT's the depressing part.

Generally, the tracking and calibration of electronic gain control devices
is tough to match electromechanically, let alone beat.

[Arny Krueger]

"Scott Dorsey" > wrote in message

> In article <znr1100624425k@trad>, Mike Rivers >
> wrote:
>>
>> In article > writes:
>>
>>> You know that Digi-Key used to carry some of the Panasonic pots with
>>> a DC motor attached. Alps makes some of those too. They seem a
>>> much more elegant way of doing remote volume control than a gadget
>>> with a bunch of CMOS switches and ladder resistors.
>>
>> The matter at hand wasn't remote volume control, it was to have a
>> single control for two channels. Of course you could do that with
>> motorized pots, but that's going to push the size, weight, and price
>> part of the "marketing requirements"
>
> Single control for two channels? Sounds like an application for DUAL
> LOG TAPER to me.
>
> Yes, I know electronic gain control devices are cheaper than dual
> pots that track well. THAT's the depressing part.

Generally, the tracking and calibration of electronic gain control devices
is tough to match electromechanically, let alone beat.

[Wayne]

>>Naw, he wants it both ways - individual control or with both channels
>>tracking.
>
>DUAL CONCENTRIC LOG TAPER.
>

Is this what you're looking for?

http://www.bartolini.net/information/accessories/accessories.htm


--Wayne

-"sounded good to me"-

[Wayne]

>>Naw, he wants it both ways - individual control or with both channels
>>tracking.
>
>DUAL CONCENTRIC LOG TAPER.
>

Is this what you're looking for?

http://www.bartolini.net/information/accessories/accessories.htm


--Wayne

-"sounded good to me"-

[Bob Cain]

Scott Dorsey wrote:
> They seem a much
> more elegant way of doing remote volume control than a gadget with a bunch
> of CMOS switches and ladder resistors.

I'm really looking for remote control but rather multiple
pre's tracking the same gain. Now that you mention it,
though... :-)


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

[Bob Cain]

Scott Dorsey wrote:
> They seem a much
> more elegant way of doing remote volume control than a gadget with a bunch
> of CMOS switches and ladder resistors.

I'm really looking for remote control but rather multiple
pre's tracking the same gain. Now that you mention it,
though... :-)


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

[Bob Cain]

Scott Dorsey wrote:

> Single control for two channels? Sounds like an application for DUAL LOG
> TAPER to me.

Actually I need quad but in any event I'm told that pots
track each other _very_ poorly and for my app that's not cool.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

[Bob Cain]

Scott Dorsey wrote:

> Single control for two channels? Sounds like an application for DUAL LOG
> TAPER to me.

Actually I need quad but in any event I'm told that pots
track each other _very_ poorly and for my app that's not cool.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

[Ralph Barone]

In article >,
(Scott Dorsey) wrote:

> Ralph Barone > wrote:
> >
> >We have discovered that laser engravers are marvelous beasts. Draw your
> >front panel up in Visio, bring the file to your local trophy shop, and
> >they will burn it onto a lamacoid sheet for you. Any shape you can
> >draw, they can cut it for you. For low-budget (albeit, non-metallic)
> >front panels, you can't beat that for price and convenience.
>
> Our neighborhood trophy shop can not only do laser engraving onto plastic
> sheets, but they can also do laser engraving onto black anodized aluminum.
> This produces really wonderfully crisp-looking panels. It's a bit more
> expensive than deep engraving, and I do like the way deep engraving feels,
> but it's possible to do very accurate positioning and work from computer
> layouts or camera-ready copy. This is a big deal if you have logos you want
> on there, or you want to put a lot of numbers around the edge of a circle
> at particular positions for an indicator knob.
> --scott

but can they cut holes in the anodized aluminum with the laser?

[Ralph Barone]

In article >,
(Scott Dorsey) wrote:

> Ralph Barone > wrote:
> >
> >We have discovered that laser engravers are marvelous beasts. Draw your
> >front panel up in Visio, bring the file to your local trophy shop, and
> >they will burn it onto a lamacoid sheet for you. Any shape you can
> >draw, they can cut it for you. For low-budget (albeit, non-metallic)
> >front panels, you can't beat that for price and convenience.
>
> Our neighborhood trophy shop can not only do laser engraving onto plastic
> sheets, but they can also do laser engraving onto black anodized aluminum.
> This produces really wonderfully crisp-looking panels. It's a bit more
> expensive than deep engraving, and I do like the way deep engraving feels,
> but it's possible to do very accurate positioning and work from computer
> layouts or camera-ready copy. This is a big deal if you have logos you want
> on there, or you want to put a lot of numbers around the edge of a circle
> at particular positions for an indicator knob.
> --scott

but can they cut holes in the anodized aluminum with the laser?

[Bob Cain]

Bob Cain wrote:
>
>
> Scott Dorsey wrote:
>
>> They seem a much
>> more elegant way of doing remote volume control than a gadget with a
>> bunch
>> of CMOS switches and ladder resistors.
>
>
> I'm really looking for remote control but rather multiple pre's tracking
^
not

> the same gain. Now that you mention it, though... :-)


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

[Bob Cain]

Bob Cain wrote:
>
>
> Scott Dorsey wrote:
>
>> They seem a much
>> more elegant way of doing remote volume control than a gadget with a
>> bunch
>> of CMOS switches and ladder resistors.
>
>
> I'm really looking for remote control but rather multiple pre's tracking
^
not

> the same gain. Now that you mention it, though... :-)


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

[Scott Dorsey]

Bob Cain > wrote:
>Scott Dorsey wrote:
>
>> Single control for two channels? Sounds like an application for DUAL LOG
>> TAPER to me.
>
>Actually I need quad but in any event I'm told that pots
>track each other _very_ poorly and for my app that's not cool.

Depends how much you pay for pots. You can get excellent tracking but you
will pay for it. The Noble can-style pots are very good in that regard.
The Alps dual-10K from Radio Shack is very bad. The price difference between
the two is about an order of magnitude.

For $475 or so, you can get a really nice six-gang 10K log taper pot from
Penny and Giles, even, which is about another order of magnitude up in price.

And you can always go the stepped attenuator route. That gives you really
phenomenally precise matching. It's expensive, but not as expensive as that
P&G if you can live with a dozen steps. If you want 24 steps, the price goes
up. Shallco makes some nice ones, or you can make your own with one of the
Elma or C&K rotary switches.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Bob Cain > wrote:
>Scott Dorsey wrote:
>
>> Single control for two channels? Sounds like an application for DUAL LOG
>> TAPER to me.
>
>Actually I need quad but in any event I'm told that pots
>track each other _very_ poorly and for my app that's not cool.

Depends how much you pay for pots. You can get excellent tracking but you
will pay for it. The Noble can-style pots are very good in that regard.
The Alps dual-10K from Radio Shack is very bad. The price difference between
the two is about an order of magnitude.

For $475 or so, you can get a really nice six-gang 10K log taper pot from
Penny and Giles, even, which is about another order of magnitude up in price.

And you can always go the stepped attenuator route. That gives you really
phenomenally precise matching. It's expensive, but not as expensive as that
P&G if you can live with a dozen steps. If you want 24 steps, the price goes
up. Shallco makes some nice ones, or you can make your own with one of the
Elma or C&K rotary switches.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Mike Rivers]

In article > writes:

> DUAL CONCENTRIC LOG TAPER.
> I don't know of anybody still making these, though.

Herein lies the problem. Designing a theoretical product is a good
palce to start, but at some time you have buy parts.


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> DUAL CONCENTRIC LOG TAPER.
> I don't know of anybody still making these, though.

Herein lies the problem. Designing a theoretical product is a good
palce to start, but at some time you have buy parts.


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> Is this what you're looking for?
> http://www.bartolini.net/information/accessories/accessories.htm

You missed the start of the movie. If the circuit can be made to work
with the available values (which seem to be more suited for guitar
pickup attentuators than gain control elements in a mic preamp) you
could use something like that for a preamp with individual gain
controls. But the "specs" call for being able to adjust the gain of
both channels with a single knob when desired.

Tying the two elements of a dual pot together with a clutch in the
concentric knobs was popular at one time, but the change of resistance
with rotation isn't consistent enough from part to part to give
accurate tracking so the stereo image doesn't shift.



--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> Is this what you're looking for?
> http://www.bartolini.net/information/accessories/accessories.htm

You missed the start of the movie. If the circuit can be made to work
with the available values (which seem to be more suited for guitar
pickup attentuators than gain control elements in a mic preamp) you
could use something like that for a preamp with individual gain
controls. But the "specs" call for being able to adjust the gain of
both channels with a single knob when desired.

Tying the two elements of a dual pot together with a clutch in the
concentric knobs was popular at one time, but the change of resistance
with rotation isn't consistent enough from part to part to give
accurate tracking so the stereo image doesn't shift.



--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> Depends how much you pay for pots. You can get excellent tracking but you
> will pay for it. The Noble can-style pots are very good in that regard.
> The Alps dual-10K from Radio Shack is very bad. The price difference between
> the two is about an order of magnitude.

When I wrote the Recording article about DIY projects, with a monitor
switcher as an example of an expandable project, I called for a Radio
Shack Alps dual 10K pot. However, I recommended buying five of them
(about $10 worth) and showed how to select a pot for best tracking. I
found two out of the lot of five that would track within better than 1
dB over most of the usable range of listening volume. I know that
isn't close enough for "mastering" but it's close enough for someone
who wants a volume control without having to click on something on the
screen.

Not too long after my article appeared (Feb 2001, for anyone who's
counting) several low cost products came on the market which served
similar functions. At the NAMM show where they all bloomed, I was
going around asking how accurate the stereo tracking was, what kind of
pots they used, and how they were selected, if at all. I got a lot of
blank stares. There are a few high quality products of this ilk, but
they range from $500 up into the thousands.

(and, to get back to the subject, it's still not a mic preamp)


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> Depends how much you pay for pots. You can get excellent tracking but you
> will pay for it. The Noble can-style pots are very good in that regard.
> The Alps dual-10K from Radio Shack is very bad. The price difference between
> the two is about an order of magnitude.

When I wrote the Recording article about DIY projects, with a monitor
switcher as an example of an expandable project, I called for a Radio
Shack Alps dual 10K pot. However, I recommended buying five of them
(about $10 worth) and showed how to select a pot for best tracking. I
found two out of the lot of five that would track within better than 1
dB over most of the usable range of listening volume. I know that
isn't close enough for "mastering" but it's close enough for someone
who wants a volume control without having to click on something on the
screen.

Not too long after my article appeared (Feb 2001, for anyone who's
counting) several low cost products came on the market which served
similar functions. At the NAMM show where they all bloomed, I was
going around asking how accurate the stereo tracking was, what kind of
pots they used, and how they were selected, if at all. I got a lot of
blank stares. There are a few high quality products of this ilk, but
they range from $500 up into the thousands.

(and, to get back to the subject, it's still not a mic preamp)


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Wayne]

>
>
>In article >
>writes:
>
>> Is this what you're looking for?
>> http://www.bartolini.net/information/accessories/accessories.htm
>
>You missed the start of the movie. If the circuit can be made to work
>with the available values (which seem to be more suited for guitar
>pickup attentuators than gain control elements in a mic preamp) you
>could use something like that for a preamp with individual gain
>controls. But the "specs" call for being able to adjust the gain of
>both channels with a single knob when desired.
>
>I'm really Mike Rivers )

Oops! I had to stop and get popcorn.


--Wayne

-"sounded good to me"-

[Wayne]

>
>
>In article >
>writes:
>
>> Is this what you're looking for?
>> http://www.bartolini.net/information/accessories/accessories.htm
>
>You missed the start of the movie. If the circuit can be made to work
>with the available values (which seem to be more suited for guitar
>pickup attentuators than gain control elements in a mic preamp) you
>could use something like that for a preamp with individual gain
>controls. But the "specs" call for being able to adjust the gain of
>both channels with a single knob when desired.
>
>I'm really Mike Rivers )

Oops! I had to stop and get popcorn.


--Wayne

-"sounded good to me"-

[james of tucson]

On 2004-11-17, Scott Dorsey > wrote:

> For $475 or so, you can get a really nice six-gang 10K log taper pot from
> Penny and Giles, even, which is about another order of magnitude up in price.

I just realized why you never see a price list attached to P&G items.

[james of tucson]

On 2004-11-17, Scott Dorsey > wrote:

> For $475 or so, you can get a really nice six-gang 10K log taper pot from
> Penny and Giles, even, which is about another order of magnitude up in price.

I just realized why you never see a price list attached to P&G items.

[Chris Hornbeck]

On 17 Nov 2004 08:55:19 -0500, (Scott Dorsey) wrote:

>And you can always go the stepped attenuator route. That gives you really
>phenomenally precise matching. It's expensive, but not as expensive as that
>P&G if you can live with a dozen steps. If you want 24 steps, the price goes
>up. Shallco makes some nice ones, or you can make your own with one of the
>Elma or C&K rotary switches.

For a good selection of "kits" with up to 4 poles, 24 steps, and nice
parts quality, you might check www.percyaudio.com catalog page 13.
You'll *never* go back to pots.

Good soldering,

Chris Hornbeck

[Chris Hornbeck]

On 17 Nov 2004 08:55:19 -0500, (Scott Dorsey) wrote:

>And you can always go the stepped attenuator route. That gives you really
>phenomenally precise matching. It's expensive, but not as expensive as that
>P&G if you can live with a dozen steps. If you want 24 steps, the price goes
>up. Shallco makes some nice ones, or you can make your own with one of the
>Elma or C&K rotary switches.

For a good selection of "kits" with up to 4 poles, 24 steps, and nice
parts quality, you might check www.percyaudio.com catalog page 13.
You'll *never* go back to pots.

Good soldering,

Chris Hornbeck

[agent86]

Mike Rivers wrote:

>
> In article > writes:
>
>> DUAL CONCENTRIC LOG TAPER.
>> I don't know of anybody still making these, though.
>
> Herein lies the problem. Designing a theoretical product is a good
> palce to start, but at some time you have buy parts.

Well, damn the bad luck!

[agent86]

Mike Rivers wrote:

>
> In article > writes:
>
>> DUAL CONCENTRIC LOG TAPER.
>> I don't know of anybody still making these, though.
>
> Herein lies the problem. Designing a theoretical product is a good
> palce to start, but at some time you have buy parts.

Well, damn the bad luck!

[Scott Dorsey]

In article >, <Garrett Cox> wrote:
>How much to build the powersupply? I assume we'd be building it. I'd be
>interested. I love reading the DIY also. Still want to piece together a
>few of Scott Dorsey's passive EQ's.

Please hurry up! I'm not getting too many orders for the passive EQ boards,
so I'm probably not going to do a second run of boards like I have for most
of the other projects.

>220 per channel is a bit of cash. I won't say steep but it is a DIY
>project for almost 2 grand. (If you do 8 channels)

The thing is that you can do the power supply and two channels today, then
you can slowly populate the boards as time goes on and you need more
channels. Of course, this works only as long as none of the parts get
discontinued in the meantime (which has happened now and then).
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

In article >, <Garrett Cox> wrote:
>How much to build the powersupply? I assume we'd be building it. I'd be
>interested. I love reading the DIY also. Still want to piece together a
>few of Scott Dorsey's passive EQ's.

Please hurry up! I'm not getting too many orders for the passive EQ boards,
so I'm probably not going to do a second run of boards like I have for most
of the other projects.

>220 per channel is a bit of cash. I won't say steep but it is a DIY
>project for almost 2 grand. (If you do 8 channels)

The thing is that you can do the power supply and two channels today, then
you can slowly populate the boards as time goes on and you need more
channels. Of course, this works only as long as none of the parts get
discontinued in the meantime (which has happened now and then).
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Rob Reedijk]

hank alrich > wrote:

> I think people think they want to build a great preamp project that
> costs less in total per channel than the price of a jensen input
> transformer. <g>

You know what, though...

I have a lot of junk in storage. Rack devices that are inferior or don't
work, or just aren't useful. But they could be excellent candidates for
scrapping for DIY projects. Think about it, they already have XLR connectors,
holes drilled in the front, and quite possibly power supplies that could
be adapted for a mic preamp project or something else. They might even
have useable output transformers.

Rob R.

[Rob Reedijk]

hank alrich > wrote:

> I think people think they want to build a great preamp project that
> costs less in total per channel than the price of a jensen input
> transformer. <g>

You know what, though...

I have a lot of junk in storage. Rack devices that are inferior or don't
work, or just aren't useful. But they could be excellent candidates for
scrapping for DIY projects. Think about it, they already have XLR connectors,
holes drilled in the front, and quite possibly power supplies that could
be adapted for a mic preamp project or something else. They might even
have useable output transformers.

Rob R.

[Paul Stamler]

"Scott Dorsey" > wrote in message
...
> In article >, <Garrett Cox>
wrote:
> >How much to build the powersupply? I assume we'd be building it. I'd be
> >interested. I love reading the DIY also. Still want to piece together a
> >few of Scott Dorsey's passive EQ's.
>
> Please hurry up! I'm not getting too many orders for the passive EQ
boards,
> so I'm probably not going to do a second run of boards like I have for
most
> of the other projects.
>
> >220 per channel is a bit of cash. I won't say steep but it is a DIY
> >project for almost 2 grand. (If you do 8 channels)
>
> The thing is that you can do the power supply and two channels today, then
> you can slowly populate the boards as time goes on and you need more
> channels. Of course, this works only as long as none of the parts get
> discontinued in the meantime (which has happened now and then).

Not real likely -- everything on the board is either a common part or a
common size.

Again, per-channel cost is down to about $150 for a basic unit (unbalanced
output, flat response, global phantom on/off), up to $175 for the fancier
unit (balanced out, switchable high-pass filter, individual channel phantom
on/off). Still assuming $25 for the board, which is still guesswork, and
will be until I lay the board out. The $220 was a typo caused by my adding
something in twice.

Peace,
Paul

[Paul Stamler]

"Scott Dorsey" > wrote in message
...
> In article >, <Garrett Cox>
wrote:
> >How much to build the powersupply? I assume we'd be building it. I'd be
> >interested. I love reading the DIY also. Still want to piece together a
> >few of Scott Dorsey's passive EQ's.
>
> Please hurry up! I'm not getting too many orders for the passive EQ
boards,
> so I'm probably not going to do a second run of boards like I have for
most
> of the other projects.
>
> >220 per channel is a bit of cash. I won't say steep but it is a DIY
> >project for almost 2 grand. (If you do 8 channels)
>
> The thing is that you can do the power supply and two channels today, then
> you can slowly populate the boards as time goes on and you need more
> channels. Of course, this works only as long as none of the parts get
> discontinued in the meantime (which has happened now and then).

Not real likely -- everything on the board is either a common part or a
common size.

Again, per-channel cost is down to about $150 for a basic unit (unbalanced
output, flat response, global phantom on/off), up to $175 for the fancier
unit (balanced out, switchable high-pass filter, individual channel phantom
on/off). Still assuming $25 for the board, which is still guesswork, and
will be until I lay the board out. The $220 was a typo caused by my adding
something in twice.

Peace,
Paul

[Geoff Wood]

"Mike Rivers" > wrote in message
>
> I don't agree with that. Dymo tape to me symbolizes an experimental or
> unfinished project. That's not what I want to trust my sound to.

Or an incredibly hi-zoop but 'played down' low key image projection....

geoff

[Geoff Wood]

"Mike Rivers" > wrote in message
>
> I don't agree with that. Dymo tape to me symbolizes an experimental or
> unfinished project. That's not what I want to trust my sound to.

Or an incredibly hi-zoop but 'played down' low key image projection....

geoff

[Geoff Wood]

"Mike Rivers" > wrote in message
news:znr1100646634k@trad...
>
> In article > writes:
>
>> Single control for two channels? Sounds like an application for DUAL LOG
>> TAPER to me.
>
> Naw, he wants it both ways - individual control or with both channels
> tracking.

How about the same in dual-concentric form factor ?!!

geoff

[Geoff Wood]

"Mike Rivers" > wrote in message
news:znr1100646634k@trad...
>
> In article > writes:
>
>> Single control for two channels? Sounds like an application for DUAL LOG
>> TAPER to me.
>
> Naw, he wants it both ways - individual control or with both channels
> tracking.

How about the same in dual-concentric form factor ?!!

geoff

[Geoff Wood]

"Kurt Albershardt" > wrote in message news:2vvqi2F2psk7gU1@uni-

>military & high grade commercial stuff. I used to buy dummy load stuff
>from them and they had a TON of pots.


Maybe they got busted ?

geoff

[Geoff Wood]

"Kurt Albershardt" > wrote in message news:2vvqi2F2psk7gU1@uni-

>military & high grade commercial stuff. I used to buy dummy load stuff
>from them and they had a TON of pots.


Maybe they got busted ?

geoff

[Geoff Wood]

"Paul Stamler" > wrote in message news:4q5nd.33589

> Again, per-channel cost is down to about $150 for a basic unit (unbalanced
> output, flat response, global phantom on/off), up to $175 for the fancier
> unit (balanced out, switchable high-pass filter, individual channel
> phantom
> on/off). Still assuming $25 for the board, which is still guesswork, and
> will be until I lay the board out. The $220 was a typo caused by my adding
> something in twice.

Maybe it would be cheaper to implement this device as a software plugin !

geoff ;-)