If a passive guitar pickup is fed through a Hi-Z to Low-Z transformer, is
the signal within the gain range of a mic preamp?

If you're talking about a Direct Box, yes, it will work.

But if you have a Direct Inject on the mic preamp itself, why not just
use that? It's one less piece of equipment and one less chord to add
noise.

--Fletch

soundhaspriority wrote:
If a passive guitar pickup is fed through a Hi-Z to Low-Z transformer, is
the signal within the gain range of a mic preamp?

More or less. The problem is that you can't really build a transformer
with a high enough input Z. If you look at a typical passive DI like the
IMP-2, you'll find they are around 10K input impedance. A typical pickup
is a lot happier with a 1M input impedance. Problem is that you can't
make a transformer with a 1M input and still get any high end; the thousands
of windings of fine wire on the primary have a lot of capacitance between
them.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

"soundhaspriority" wrote in message
...
If a passive guitar pickup is fed through a Hi-Z to Low-Z transformer, is
the signal within the gain range of a mic preamp?

Typically yes.

Peace,
Paul

"Scott Dorsey" wrote in message
...
soundhaspriority wrote:
If a passive guitar pickup is fed through a Hi-Z to Low-Z transformer, is
the signal within the gain range of a mic preamp?

More or less. The problem is that you can't really build a transformer
with a high enough input Z. If you look at a typical passive DI like the
IMP-2, you'll find they are around 10K input impedance. A typical pickup
is a lot happier with a 1M input impedance. Problem is that you can't
make a transformer with a 1M input and still get any high end; the
thousands
of windings of fine wire on the primary have a lot of capacitance between
them.

You can actually get a lot better than 10k. The Jensen DI transformer, for
example, has a 12:1 turns ratio, so it will multiply the load impedance it
sees by 144 (square of the turns ratio). If the load is 1500 ohms, then the
guitar will see 216k. If the load's 2.2k, then the guitar will see about
317k. It's still not 1M, but it's a lot closer than you'd guess by looking
at the transformer's stated impedances.

Peace,
Paul

soundhaspriority goodscience.org wrote:
If a passive guitar pickup is fed through a Hi-Z to Low-Z transformer, is
the signal within the gain range of a mic preamp?

"Scott Dorsey" panix.com wrote:
More or less. The problem is that you can't really build a transformer
with a high enough input Z. If you look at a typical passive DI like the
IMP-2, you'll find they are around 10K input impedance. A typical pickup
is a lot happier with a 1M input impedance. Problem is that you can't
make a transformer with a 1M input and still get any high end; the
thousands windings of fine wire on the primary have a lot of capacitance
between them.

Paul Stamler wrote:
You can actually get a lot better than 10k. The Jensen DI transformer, for
example, has a 12:1 turns ratio, so it will multiply the load impedance it
sees by 144 (square of the turns ratio). If the load is 1500 ohms, then the
guitar will see 216k. If the load's 2.2k, then the guitar will see about
317k. It's still not 1M, but it's a lot closer than you'd guess by looking
at the transformer's stated impedances.


Yes, and most passive magnetic (electric) guitar pickups
will by satisfied by load impedences above 100k or so.

If it's a piezo or other very high impedence pickup it may
want to see a much higher load to sound decent. This
may also contribute to the (somewhat) bad rap these
pickups get.

rd

"Fletch" wrote in message
oups.com...
If you're talking about a Direct Box, yes, it will work.

But if you have a Direct Inject on the mic preamp itself, why not just
use that? It's one less piece of equipment and one less chord to add
noise.

Field mixer/preamps don't have a Direct input.

On 26 May 2006 15:02:55 -0400, (Scott Dorsey) wrote:

soundhaspriority wrote:
If a passive guitar pickup is fed through a Hi-Z to Low-Z transformer, is
the signal within the gain range of a mic preamp?

More or less. The problem is that you can't really build a transformer
with a high enough input Z. If you look at a typical passive DI like the
IMP-2, you'll find they are around 10K input impedance. A typical pickup
is a lot happier with a 1M input impedance. Problem is that you can't
make a transformer with a 1M input and still get any high end; the thousands
of windings of fine wire on the primary have a lot of capacitance between
them.
--scott

An interesting sideline to this discussion is that with the volume up,
the guitar is essentially an inductive source, so even substantial
inductive loading will attenuate more than changing the tone etc.
Going even further, the transformer will reduce the overall inductance
of the parallel tuned circuit, increasing the frequency of the
resonant peak (parallel capacitance will restore/add as much warmth as
anyone could want). So as long as the transformer is good for 10k ohms
or so reactance at 100Hz (2k at 20Hz, up to 300k at 3kHz; more is
still better) it should work, albeit with some EQ-able tone change.
The reflected impedance (load times TurnsRatio squared) should still
be preferably 200k+, but such a transformer would have no trouble with
that in the upper midrange - it's nowhere near as critical as it might
seem.

Tony
Tony (remove the "_" to reply by email)

Tony wrote:

An interesting sideline to this discussion is that with the volume up,
the guitar is essentially an inductive source, so even substantial
inductive loading will attenuate more than changing the tone etc.

Yes, absolutely. When I was designing a reamplification box, I checked
some pickups and found from 1Hy to 5Hy or so effective. That's very
inductive.

Going even further, the transformer will reduce the overall inductance
of the parallel tuned circuit, increasing the frequency of the
resonant peak (parallel capacitance will restore/add as much warmth as
anyone could want). So as long as the transformer is good for 10k ohms
or so reactance at 100Hz (2k at 20Hz, up to 300k at 3kHz; more is
still better) it should work, albeit with some EQ-able tone change.
The reflected impedance (load times TurnsRatio squared) should still
be preferably 200k+, but such a transformer would have no trouble with
that in the upper midrange - it's nowhere near as critical as it might
seem.

Right, but the problem is that there is high end rolloff due to
inter-winding capacitance on the primary if you make the impedance
super-high.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

(Scott Dorsey) wrote in news:e587ju$3fc$1
@panix2.panix.com:

Right, but the problem is that there is high end rolloff due to
inter-winding capacitance on the primary if you make the impedance
super-high.

And this is why active DI boxes are so popular?

**Field mixer/preamps don't have a Direct input.**

You never mentioned that in your original post. How are we to know if
you don't provide this information?

--Fletch

Carey Carlan wrote:
(Scott Dorsey) wrote in news:e587ju$3fc$1
:

Right, but the problem is that there is high end rolloff due to
inter-winding capacitance on the primary if you make the impedance
super-high.

And this is why active DI boxes are so popular?

Right. And it's why high ratio Jensen transformers cost a whole lot
more than Tamuras.
--scott


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

"Fletch" wrote in message
ups.com...
**Field mixer/preamps don't have a Direct input.**

You never mentioned that in your original post. How are we to know if
you don't provide this information?

--Fletch

I asked this question: If a passive guitar pickup is fed through a Hi-Z to
Low-Z transformer, is
the signal within the gain range of a mic preamp?

"Robert Morein" wrote ...
"Fletch" wrote ...
**Field mixer/preamps don't have a Direct input.**

You never mentioned that in your original post. How are we to know if
you don't provide this information?

--Fletch

I asked this question: If a passive guitar pickup is fed through a
Hi-Z to Low-Z transformer, is the signal within the gain range of a
mic preamp?

Maybe. Too many variables to give a definitive answer.
Depends on all of these (and a few more):
1) The output level of the passive pickup
2) The ratio/loss of the Hi-Z unbal to Lo-Z bal transformer
3) The gain/SNR of the mic preamp.

"Richard Crowley" wrote in message
...
"Robert Morein" wrote ...
"Fletch" wrote ...
**Field mixer/preamps don't have a Direct input.**

You never mentioned that in your original post. How are we to know if
you don't provide this information?

--Fletch

I asked this question: If a passive guitar pickup is fed through a Hi-Z
to Low-Z transformer, is the signal within the gain range of a mic
preamp?

Maybe. Too many variables to give a definitive answer.
Depends on all of these (and a few more):
1) The output level of the passive pickup
2) The ratio/loss of the Hi-Z unbal to Lo-Z bal transformer
3) The gain/SNR of the mic preamp.
Thanks, this is what I'm being told from multiple sources. It appears that
an active direct box is a more optimal solution. I'm looking at
http://www.samsontech.com/products/p...1754&brandID=2

What bothers me is the price. Are there noticeable quality differences in
direct boxes? Does the street price of $50 automatically imply it will be a
POS?

"Robert Morein" wrote ...
Thanks, this is what I'm being told from multiple sources. It appears
that an active direct box is a more optimal solution. I'm looking at
http://www.samsontech.com/products/p...1754&brandID=2

What bothers me is the price.

I didn't see any price listed. You are bothered because
whatever the price is too high or too low?

Are there noticeable quality differences in direct boxes? Does the
street price of $50 automatically imply it will be a POS?

Not necessarily. Dunno anybody who holds "Samson"
out as a model of audio quality, but the last Stewart
direct box I bought was ~$75

"Richard Crowley" wrote in message
...
"Robert Morein" wrote ...
Thanks, this is what I'm being told from multiple sources. It appears
that an active direct box is a more optimal solution. I'm looking at
http://www.samsontech.com/products/p...1754&brandID=2

What bothers me is the price.

I didn't see any price listed. You are bothered because
whatever the price is too high or too low?

Too low.

Are there noticeable quality differences in direct boxes? Does the street
price of $50 automatically imply it will be a POS?

Not necessarily. Dunno anybody who holds "Samson"
out as a model of audio quality, but the last Stewart
direct box I bought was ~$75

In article , "Robert Morein"
wrote:

"Richard Crowley" wrote in message
...
"Robert Morein" wrote ...
Thanks, this is what I'm being told from multiple sources. It appears
that an active direct box is a more optimal solution. I'm looking at
http://www.samsontech.com/products/p...1754&brandID=2

What bothers me is the price.

I didn't see any price listed. You are bothered because
whatever the price is too high or too low?

Too low.

Are there noticeable quality differences in direct boxes? Does the street
price of $50 automatically imply it will be a PO

Sorry guys, forgery.

Brian,
You used to be a professional sound mixer. Have some respect for these
people.

Richard Crowley wrote:

"Robert Morein" wrote ...
Thanks, this is what I'm being told from multiple sources. It appears
that an active direct box is a more optimal solution. I'm looking at
http://www.samsontech.com/products/p...1754&brandID=2

What bothers me is the price.

I didn't see any price listed. You are bothered because
whatever the price is too high or too low?

Are there noticeable quality differences in direct boxes? Does the
street price of $50 automatically imply it will be a POS?

Not necessarily. Dunno anybody who holds "Samson"
out as a model of audio quality, but the last Stewart
direct box I bought was ~$75

The Whirlwind IMP2 is at least decent and runs about $45.
The Whirlwind with the Jensen is excellent at about $175.
The radial has the same Jensen and is about $150.
You can get the same X-former direct from Jensen for about $80 & use your
own box.

Then there's the active boxes like the Countryman. For about the same money
as the Jensen-equipped boxes, you get input impedance as high as an
elephant's eye. That's what I mostly use with passive pickups (and ALWAYS
with piezos). But watch out for some or the cheap actives, as they can be
noisy. Just like with passive DIs, you get pretty much whatyou pay for.

Robert Morein wrote:

I asked this question: If a passive guitar pickup is fed through a Hi-Z to
Low-Z transformer, is the signal within the gain range of a mic preamp?

Quite possibly, but it depends on the pickup, the transformer, and the
gain range of the mic preamp. If you're talking about one of those
Radio Shack in-line transformers, you're likely to get a usable signal
level through it. You might not like the low end or the distortion,
however.

Transformers cost more as the quality improves. A bare Jensen direct
box transformer (as used in the best passive DI boxes) costs about $75.
Impedance on the guitar side is 200K, and on the mic preamp side, 1.5K.
Maximum input level is +22 dBu (and a really hard-hit guitar with a
hot pickup can get close to that level). THD at 1 kHz is specified as
less than 0.001%, and 0.036% at 20 Hz. Compare whatever transformer
you're looking at to this one to see how close it comes to what's
considered the "gold standard" of DI transformers.

An active DI can be cheaper, but the cheaper it is, the noisier,
usually. Or it can be more expensive, as quiet as a transformer, and
provide a higher input impedance to the guitar. 200K Ohms is generally
high enough for all but bare piezoelectric pickups, however.

"Mike Rivers" wrote in message
ups.com...

[snip]

An active DI can be cheaper, but the cheaper it is, the noisier,
usually. Or it can be more expensive, as quiet as a transformer, and
provide a higher input impedance to the guitar. 200K Ohms is generally
high enough for all but bare piezoelectric pickups, however.

Would appreciate a recommendation for a quiet, active, battery powered
direct box, if such a thing exists.

Robert Morein wrote:

Would appreciate a recommendation for a quiet, active, battery powered
direct box, if such a thing exists.

The Countryman 85 is pretty much the standard for a high quality direct
box without getting into the esoteric tube stuff. It runs off a 9V
battery or 48V phantom power. List price is about $200, however I've
seen it new on-line for as low as around $150. Good things don't come
cheap, and cheap things don't come good.

http://www.countryman.com/html_data_sheets/t85data.html

"Mike Rivers" wrote in message
oups.com...

Robert Morein wrote:

Would appreciate a recommendation for a quiet, active, battery powered
direct box, if such a thing exists.

The Countryman 85 is pretty much the standard for a high quality direct
box without getting into the esoteric tube stuff. It runs off a 9V
battery or 48V phantom power. List price is about $200, however I've
seen it new on-line for as low as around $150. Good things don't come
cheap, and cheap things don't come good.

http://www.countryman.com/html_data_sheets/t85data.html

Thanks, I'll go with that.

"Robert Morein" wrote in message
...

"Mike Rivers" wrote in message
oups.com...

Robert Morein wrote:

Would appreciate a recommendation for a quiet, active, battery powered
direct box, if such a thing exists.

The Countryman 85 is pretty much the standard for a high quality direct
box without getting into the esoteric tube stuff. It runs off a 9V
battery or 48V phantom power. List price is about $200, however I've
seen it new on-line for as low as around $150. Good things don't come
cheap, and cheap things don't come good.

http://www.countryman.com/html_data_sheets/t85data.html

Thanks, I'll go with that.

A better choice for similar money: http://www.radialeng.com/di-j48.htm

A better choice for more money: http://www.radialeng.com/di-jdv.htm

In article , "Tim Padrick"
wrote:
"Robert Morein" wrote in message
...

"Mike Rivers" wrote in message
oups.com...

Robert Morein wrote:

Would appreciate a recommendation for a quiet, active, battery powered
direct box, if such a thing exists.

The Countryman 85 is pretty much the standard for a high quality direct
box without getting into the esoteric tube stuff. It runs off a 9V
battery or 48V phantom power. List price is about $200, however I've
seen it new on-line for as low as around $150. Good things don't come
cheap, and cheap things don't come good.

http://www.countryman.com/html_data_sheets/t85data.html

Thanks, I'll go with that.

A better choice for similar money: http://www.radialeng.com/di-j48.htm

A better choice for more money: http://www.radialeng.com/di-jdv.htm

Can't you follow a simple thread? I already made up my mind, I picked the
Countryman.

Too many complicated decisions, I'm recording a CD MY way, and all you
so-called professionals have too many nit-picking ideas.

Bob

"Tim Padrick" wrote in message
...

"Robert Morein" wrote in message
...

"Mike Rivers" wrote in message
oups.com...

Robert Morein wrote:

Would appreciate a recommendation for a quiet, active, battery powered
direct box, if such a thing exists.

The Countryman 85 is pretty much the standard for a high quality direct
box without getting into the esoteric tube stuff. It runs off a 9V
battery or 48V phantom power. List price is about $200, however I've
seen it new on-line for as low as around $150. Good things don't come
cheap, and cheap things don't come good.

http://www.countryman.com/html_data_sheets/t85data.html

Thanks, I'll go with that.

A better choice for similar money: http://www.radialeng.com/di-j48.htm

A better choice for more money: http://www.radialeng.com/di-jdv.htm
Interesting. I do have a Denecke phantom supply, perhaps I'll go with that,
thanks.

X-Complaints-To:
NNTP-Posting-Date: Sat, 27 May 2006 18:23:31 PDT
Organization: BuzzardNews.Com
Date: Sun, 28 May 2006 08:23:26 +0700
X-Received-Date: Sun, 28 May 2006 01:23:32 GMT
(bgtnsc04-news.ops.worldnet.att.net)

Any chance you kids could take this elsewhere?

Didn't think so. Good luck in life. You'll need it.

Chris Hornbeck

"Chris Hornbeck" wrote in message
...
X-Complaints-To:
NNTP-Posting-Date: Sat, 27 May 2006 18:23:31 PDT
Organization: BuzzardNews.Com
Date: Sun, 28 May 2006 08:23:26 +0700
Xref: wnmaster12 rec.audio.pro:1178706
X-Received-Date: Sun, 28 May 2006 01:23:32 GMT
(bgtnsc04-news.ops.worldnet.att.net)

Any chance you kids could take this elsewhere?

Didn't think so. Good luck in life. You'll need it.

Chris Hornbeck

Chris, I have a stalker. His name is Brian L. McCarty. I can't do anything
about it.

Regards,
Bob Morein

On Sun, 28 May 2006 01:33:07 -0400, "Robert Morein"
wrote:

Chris, I have a stalker. His name is Brian L. McCarty. I can't do anything
about it.

There's never nothing. You start by posting headers, etc.
Real news readers can filter almost any patheticism.

Good luck with your issue, but please don't crosspost
into r.a.p from r.a.o; you're winning no friends, and
only diminish credibility.

All the best,

Chris Hornbeck

"Robert Morein" wrote in message
.. .

Can't you follow a simple thread? I already made up my mind, I picked the
Countryman.

Too many complicated decisions, I'm recording a CD MY way, and all you
so-called professionals have too many nit-picking ideas.

Then why do you bother to ask us questions?

Peace,
Paul

"Robert Morein" wrote in
:

Chris, I have a stalker. His name is Brian L. McCarty. I can't do
anything about it.

You can ignore him like we do. Internet personal attacks carry zero
weight.

Not sure if this is a side note or answering the basic question. But
you might check out a new product called the Redeemer from Creation
Audio. At the risk of totally blowing the technical description, It's a
brand new kind of circuit that takes the original signal from the
output of the guitar and drives the current to make it a low impedance
signal. My understanding is that it is NOT an active buffer amp, but
something new with no transformers to match up. Basically you can drive
a really long cable without signal loss or go straight into a direct
(mixer) input with a full sound. It makes a BIG difference. Makes amps
sound great! Makes direct guitar sound great! And I think it costs
around $150. Well worth it. You can have one installed directly in the
guitar, or there is also a stompbox version (my preference for
recording).
Cheers,
Lij

"Lij" wrote ...
Not sure if this is a side note or answering the basic question. But
you might check out a new product called the Redeemer from Creation
Audio. At the risk of totally blowing the technical description, It's
a
brand new kind of circuit that takes the original signal from the
output of the guitar and drives the current to make it a low impedance
signal. My understanding is that it is NOT an active buffer amp, but
something new with no transformers to match up. Basically you can
drive
a really long cable without signal loss or go straight into a direct
(mixer) input with a full sound. It makes a BIG difference. Makes amps
sound great! Makes direct guitar sound great! And I think it costs
around $150. Well worth it. You can have one installed directly in the
guitar, or there is also a stompbox version (my preference for
recording).

From the photos and the description, "an active buffer amp"
is exactly what it is. Not that there is anything wrong with
that unless you are Creation Audio Lab's marketing gerb who
is trying to distinguish themselves from their competition.

OTOH, it appears to be designed to install in the instrument
so that it has a low impedance output and is no longer dependent
on the difficulties of that Hi-Z path from the instrument to the
amp. It does NOT appear to be any kind of "direct box" like
function. For example, the output appears to be unbalanced.

It has published specs for freq response, distortion, input and
output impedance, but studiously avoids any reference to
signal levels. This would lead one to believe that it is a zero
gain impedance buffer.

"Paul Stamler" wrote in message
...
"Robert Morein" wrote in message
.. .

Can't you follow a simple thread? I already made up my mind, I picked the
Countryman.

Too many complicated decisions, I'm recording a CD MY way, and all you
so-called professionals have too many nit-picking ideas.

Then why do you bother to ask us questions?

Peace,
Paul

Paul, it's a forgery.

Peace,
Bob Morein