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Ian Iveson Ian Iveson is offline
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Default Which tube expert can do custom works?

robert casey said:

Incidentally, surely a *good* tube buffer should be
transparent so it couldn't
have any effect in that scenario ?


Well, then there's no point in specifying the use of tubes
in the first place then. In which case, this newsgroup
has no valid reason to exist... Anyway.


You have my sympathy, Robert.

I would not myself support the assertion that a good SS
circuit is necessarily more "accurate" or "transparent" or
"self effacing" than one using valves, so your case falls
there from my POV. I haven't given up on the idea that
valves are more suited to high fidelity. The argument that
valves are for people who like the sound of distortion is
shallow and false.

None of which excuses eeyore's subsequent twisting non
sequitur. He suggested "transparent", you object on the
grounds that there would then be no point in using valves,
and he comes back like you'd both said the opposite, and
blurts whatever he thinks his intended victim might want to
hear.

But then you've been here as long as I have, so I guess you
know the score.

Oh, and BTW, "accurate" in this context is a bit
presumptuous, IMO, and "transparent" is ambiguous in general
usage these days. And "self-effacing" is vague and weak as
dishwater.

cheers, Ian


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Ian Iveson Ian Iveson is offline
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John Byrns asked:

Who would be the last person in the world you would trust
with such a
task?


"Me", is the answer I had in mind. But really it was a
device, to avoid hurting Graham's feelings.

cheers, Ian


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Ian Iveson Ian Iveson is offline
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Perhaps you missed the word "recreational" in the newsgroup
title?

Don't let me put you off, but I find your whole approach
tacky and foolish.

What have you contributed here, parasite?

Top posted in utter disdain.

Ian

"Tynan AgviŠr" wrote in message
. 3.70...
All I am saying is that experts normally want some sort
of
"professional" fee,
ie, more than what you'd pay a cleaner.
And you have not indicated what you are prepared to pay.

Doing such design work takes considerable time.

If you really want something done, and done right,
and in a good time frame, make a deal nobody can refuse.

I'm extremely busy for the next 6 months can't help you
right now.

Does not Manley Labs have something you might purchase
off the shelf?

Patrick Turner.


Ok, sure I expect that most people require a fee..but I
generally dont
talk about money on public newsgroups. That is pretty
tacky in my
opinion. On top of that..I dont know what a project like
that would go
for because nothing like that exists! Ive seen a lot of
talk about money,
but normally when I get audio work done(I get a lot of
microphone
modifications, for example), I tell the two techs that I
deal with mainly
what I am looking for, they do research, give me cost
scenarios, and
that's that. Why would I come on here, like an idiot, say
"hey, I am a
dumbass numbnuts who doesnt know anything about nothing",
"ive got XXXX.
dollars here, and I want someone to build me a mixer."
"Who can do it?",
..Nothing about that seems smart. Ive never done business
that way, and
dont intend on ever doing it that way. I had hoped someone
would contact
me(and they have) , do a little brain storming with those
expert brains
of theirs, get back to me with a figure and some scenario
of what they
could do, yadda yadda. And lets work it out.. as for the
things you
said.. *ive* never known any expert do do business in
that manner. I
dont want to approach this like an auction or a contract
to build a
prison. I want someone to talk to me one on one and work
with me. Ive had
4 guys offer very helpful information(helping me narrow
down what I want,
and believe me I appreciate it very very much), but
outside of those guys
(thanks be to them again), i hear a lot of talk about
money, but no talk
about what someone could offer. do people really think
that way?? "Give
me money and we can talk!"..if so that is bull****!..Hell,
how do I know
you aren't some Schizo in Dorothea Dix or Joe Blow from
piscopo..hell...or that you know your 3rd point of contact
from a hole in
the ground?
Obviously you cant help, Mr. Turner.. thats cool..but I
did want to
answer your questions.


As for manley..Well, I dont need anything as large as what
they offer,
and they dont do anything smaller...they are pretty much
on the verge of
"mass production" , and I want something that is mine(and
the builders)
alone.

Ill keep hoping, maybe theyll come along.






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robert casey robert casey is offline
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If you want a clinically accurate circuit, solid state is the way to
go. National Semiconductor for one are making op-amps now with THD
well over 100dB below signal level.

Though I'm not enough of a mathematician to rigously express it,

my gut feeling is that op-amps with the tons of negative feedback
is not a great device for audio work. Non-linearities will create
harmonics and intermodulation products. Then you try to cancel that all
out with the feedback, but as you may cancel most of the lower order
crud, you then create even more higher order harmonics and
intermodulation products. And that loops back yet again. But there's a
time delay in getting that feedback signal to the input, which means you
can never cancel the leading edge of crud products. Thus it's better to
use small amounts of feedback on circuits that are pretty good even
without feedback. That's discrete bipolar or FET transistors and tubes.


Sir, I dont want a clinically accurate circuit. I dont want solid state and
op-amps(though I do have some very nice amps that Use ICs that were made by
Mr. Mick Hinton(DAV Electronics)..I use them a lot and am quite fond of
them....but I want what I stated when I first posted..(which Rudy has
translated for me(thanks Rudy, you said what I was trying to say in fewer
and better words,)


One thing to remember is that tube equipment will get warmer than SS.
From the heaters, mostly with a mixer I would think (it'd be mostly
12AX7s and 12AU7s and such, yes?). Lots of vent slots underneath and on
the sides and back for natural air flow. You won't want fans, as those
are noisy and you surely don't want that when doing critical audio work.
Use DC on the heaters, no point in risking induced hum in the mixer
circuits. And keep the heater supply and returns separate from the
other circuits except for a single tie point to ground it all.

and no, to re-iterate..I am not trying to pick brains so I can steal
secrets.


Oh, at least with me, don't worry about that, as I've always worked for
large corporations where one's work really has no impact on the
company's bottom line.
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Andre Jute Andre Jute is offline
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On Jan 8, 12:38*pm, "Ian Iveson"
wrote:
Eeyore wrote

You may choose to have an old mixer made new, in which
case
you need someone who can copy whichever old circuit you
like
and build it to your quality expectations. You wouldn't
need
a designer.


The designer would be able to adapt that circuit to use
modern (and
reliable) constructional techniques, without which the
project might
never get off the ground.


Well that depends on what is meant by "design".

If an engineer were to take an old design and adapt it,
using modern passives and peripheral circuits, and build it
to current state-of-the-art spec., would that be design?

Anyway, what I was trying to do was draw attention to the
difference between the engineering task, and the voicing,
for want of a better word.

There aren't many people I would trust with both. Add the
need to appreciate the all-valve studio context the mixer
will find itself in, and there can't be many people in the
world who would be fully qualified for the job.

Patrick's point about the need for commissioning underlines
this issue. However, that requirement for close and
continuing relations with the customer could be obviated if
the product were a functional replica of some classic
design. That would take care of the issue of voicing in
advance.

In my own language, I would say that authenticity is the
safest route to legitimacy.

Unless, for the customer, *any* sound resulting from a valve
circuit would be equally legitimate. In that case, even you
might be able to do the job, although you would be the
second-last person in the world I would trust with such a
task.

A mixer of the vintage he's interested in will now be
ultra-exceptionally rare (they were exceptionally rare to
begin with !)
and likely already in the hands of a well-heeled rock star
or the like.
Indeed I know of a couple of former EMI desks (one tubed
and one
germanium transistor) in such ownership.


If you can copy the circuit without messing it up, you may
have a head start. I still wouldn't trust you with it, but
don't let that dampen your ardour, or sway the customer, who
I am sure can survey your history of postings and judge for
himself.

I would probably trust Rudy, BTW, and a couple of others
round here least given to self-aggrandising delusions.

Ian


Ian has a sound point. Besides the professionals here, there are quite
a few senior hobbyists, perhaps a handful altogether, who could work
out how to design and build such thing. But, and it is a monstrously
big but, there is a difference between designing and building a
machine, and voicing that machine. Voicing is absolutely the essence
here, because if different voicing is not wanted the OP may as well
buy lowest common denominator equipment off the shelf by features and
THD spec and reputation. The OP is going about it entirely wrong in
coming on RAT with his idea; he should first have found someone
capable of designing electronic equipment with whom he is culturally
in tune, and then approached that person privately with his dream. I'm
not just talking: I built a studio amp for a rocker down the road,
paid exquisite attention to what he wanted in the voicing, left him
deliriously happy with his amp -- and I absolutely despised the
brutish sound it made in its normal mode (that experience is the
source of my reflexive sneer every time someone mentions KT88...) It
was a total waste of a lot of my time; I learned nothing I want to
know, only what I didn't want to know (1), and half of that was simply
reinforcement since I already knew I despise the sound NFB makes.
Money is small recompense for such a waste. I went back to what I have
always done, creating things that reflect my own taste, take it or
leave it.

Andre Jute
"I was at a board meeting for the LA Chapter of the Audio Engineering
Society last night on XM Satellite radio audio and data transmission.
Sadly, we missed you there, and at the SMPTE and Acoustical Society
recent meetings as well. Everyone was asking, 'Where is that wonderful
Andre Jute? The world just doesn't rotate without him...'" -- John
Mayberry, Emmaco

(1) Okay, I did get to listen to a whole wall of Marshall stacks,
which gave me a nostalgic twinge for my party setup back in my
twenties, when a small party was only my 400 closest friends, when I
drove a wall of speakers we kept beside the pool for touring rock acts
with several hi-watt amps a couple of mates at HP designed and built
for me; the police received calls from as far away as three miles.


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Phil Allison Phil Allison is offline
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"robert casey"

Though I'm not enough of a mathematician to rigously express it,

my gut feeling



** Not really any way to do science or engineering.

Gut feelings are what primitive man used instead of "science", as did the
Alchemists, all manner of fakers and charlatans - and now that the human
race knows better - complete * ****wits * like you come along and want
to drag us all back to the pig ignorance of the Dark Ages.


is that op-amps with the tons of negative feedback
is not a great device for audio work. Non-linearities will create
harmonics and intermodulation products. Then you try to cancel that all
out with the feedback, but as you may cancel most of the lower order crud,
you then create even more higher order harmonics and intermodulation
products. And that loops back yet again.



** Total and ABSOLUTE ******** !!!!!!!!!!!!!!!!!




....... Phil




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Ian Thompson-Bell Ian Thompson-Bell is offline
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Eeyore wrote:

Oh right. You'd dismiss the only pro-audio design engineer posting here.


And who would that be, then?

Ian
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Ian Iveson wrote:

Eeyore blethered:

I would probably trust Rudy, BTW, and a couple of others
round here least given to self-aggrandising delusions.


Oh right. You'd dismiss the only pro-audio design engineer
posting here.

Your rampant amateurism knows no bounds.


Indeed not. I'm proud to be an amateur, and happy to know no
bounds. Being rampant is icing on the cake.


You're such an amateur that you regularly post complete nonsense here
that anyone who understands even basic electronic theory would find
laughable. You are quite frankly a PEST who messes up serious threads
with faulty ideas and abusive comments. I can't think of even a single
occasion when you've been right about a technical matter.


Unlike your failed products, bounded firstly by failure in
the market, and then by the ruin of your employer.


Failed products ? Some of them sold over 100,000 units. You have a funny
idea of failure.

It seems that Tynan AgviŠr isn't fooled by your posturing.

Graham

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robert casey wrote:

If you want a clinically accurate circuit, solid state is the way to
go. National Semiconductor for one are making op-amps now with THD
well over 100dB below signal level.


Though I'm not enough of a mathematician to rigously express it,

my gut feeling is that op-amps with the tons of negative feedback
is not a great device for audio work.


Your 'gut feeling' is clearly defective. You're probably stuck with a 60s / 70s
idea of semicondcutor circuitry.


Non-linearities will create harmonics and intermodulation products.


130dB down with, for exampe, the LME49710.

Are you SERIOUSLY saying that you can hear THD that's -130dB ?

Now, valve / tube circuitry regularly has THD figures that are ~ -60dB. You would
appear to be saying that THD @ -60dB that's 'good tube distortion' is inaudible
(or 'transparent' / other value judgement etc) yet THD @ -130dB that's 'bad
solid-state distortion' is clearly audible.

Can you see the obvious weakness of your case.

Graham

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Eeyore Eeyore is offline
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robert casey wrote:

Then you try to cancel that all out with the feedback


That's NOT how feedback works (in some sequential manner). You should learn
something about proper feedback theory.

Graahm



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Eeyore Eeyore is offline
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robert casey wrote:

But there's a time delay in getting that feedback signal to the input


WRONG again.

These are all classic audiophool fallacies, along with magic wire, shakti stones
and the rest.

Graham

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Andre Jute wrote:

"Ian Iveson" wrote:

I would probably trust Rudy, BTW, and a couple of others
round here least given to self-aggrandising delusions.

Ian


Ian has a sound point.


Ian is a blithering idiot who is incapable of being right about anything
of importance. He has a cabbage for a brain.

Graham

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Andre Jute wrote:

Voicing is absolutely the essence here


I imagine the OP wants 'triode' voicing actually. That's the classic tube
sound when used in preamp circuitry.

However pentodes have also been widely used in high sensitivity mic
preamps so it might be a good idea to ascertain which characteristic is
desired.

Graham

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Phil Allison wrote:

"robert casey"

Though I'm not enough of a mathematician to rigously express it,

my gut feeling


** Not really any way to do science or engineering.

Gut feelings are what primitive man used instead of "science", as did the
Alchemists, all manner of fakers and charlatans - and now that the human
race knows better - complete * ****wits * like you come along and want
to drag us all back to the pig ignorance of the Dark Ages.

is that op-amps with the tons of negative feedback
is not a great device for audio work. Non-linearities will create
harmonics and intermodulation products. Then you try to cancel that all
out with the feedback, but as you may cancel most of the lower order crud,
you then create even more higher order harmonics and intermodulation
products. And that loops back yet again.


** Total and ABSOLUTE ******** !!!!!!!!!!!!!!!!!


Yet popular belief amongst the audiophools. Belief being the relevant word since
it is some quasi-religion based on exaggered and misapplied half-truths combined
with outright lies.

Graham

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Ian Thompson-Bell wrote:

Eeyore wrote:

Oh right. You'd dismiss the only pro-audio design engineer posting here.


And who would that be, then?


Are you claiming to be active in this field still ? Did you do design ? I
honestly don't know. You're not a regular enough poster for me to know that
much about you.

Graham



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Ian Iveson Ian Iveson is offline
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Eeyore continued:

It seems that Tynan AgviŠr isn't fooled by your
posturing.


Why should I care, why should I posture, and quite what
posture do you believe I have adopted?

Submit a sample schematic of a valve circuit of your design.
Let's see what you can really do.

Ian


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Perhaps you missed the word "recreational" in the newsgroup
title?

Don't let me put you off, but I find your whole approach
tacky and foolish.

What have you contributed here, parasite?

Top posted in utter disdain.


Skirting the issue of name calling..I havent claimed to be of any
consequence to this group. I am just a musician and part time recording
engineer who loves the sound of tube gear. Noting the volume of the posts
here, and at reccomendation of one of my good friends, I figured I would
drop a line and see if someone could steer me in the right direction. Why
that gives some of you sand in your vaginas I have no idea. Normally when
People post to groups I am a part of and are looking for engineers, and I
am a good fit, I jump at the chance. I certainly dont whine and try to
discourage people from seeking my (or anyone elses) services..In this age
of DIY I recognize the value of those who still need the services of audio
veterans. This thread has left me a bit confused and more than a little
amused.


Graham, Rudy , Andre and others..thanks for keeping this on track(while
managing to spar with Mdme Ian, impressive)


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Eeyore wrote in
:



Andre Jute wrote:

Voicing is absolutely the essence here


I imagine the OP wants 'triode' voicing actually. That's the classic
tube sound when used in preamp circuitry.

However pentodes have also been widely used in high sensitivity mic
preamps so it might be a good idea to ascertain which characteristic
is desired.

Graham


Well...I will say this. My favorite mic preamps are VACRAC, Electronaut
m63, and Pendulum MDP-1.They have that "sound" , and are versatile/low
noise enough so that I can stack tracks all day without ever feeling
bogged down(unlike many other preamps that really do not play that game
very well) I am looking for a mixer that will give me results sonically
along those lines. I wish I were more adept technically, but I will try
to answer questions as best I can. I know about the heat issue, weight,
etc. (and no, as far as the above companies..none of them do mixers)

I am also in love with my integrated amp, and spent many many hours
demoing pieces from all over(in widely varying price ranges) before
finding it and deciding that it was the one instantly.

it is here
http://www.mastersoundsas.it/NEW%20S...0Due%20Venti%2
0manuale%20ingleseA.pdf
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"Tynan AgviŠr" wrote in message
. 3.70...
I am a recording engineer, and I would like to check with some persons who
are working with tube audio equipment(making it) about manufacturing for

me
a custom 8 in, 2 out tube based mixer. I record all acoustic music,

chamber
music, folk, bluegrass, celtic, world music, choir, acapella, etc. there a
lot of mass produced choices, but I would like something very special. I
have spoken to MOSCODE months ago, and he said he would do it, but then
never answered my last emails. If anyone can help me, I would much
appreciate it, and will send you all the first recordings of my label
(audiophile type label beginning late this year).

Tackar så mycket,

-Tynan


The sound of money seem to blind some of our best Rodents. Take $$ out of
the equation and it will be easy to see the obvious TROLL.

west


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Ian Thompson-Bell wrote:

Agreed. At Neve there were standard systems in place for
the physical framework design/build, silk screening, key
cap engraving, with standard screened modules, mix bus
extrusion and power and signal routing. Which is why I
used the phrase *at least*. I just wanted the OP to have a
ball park figure to contemplate.


One problem small producers have in making the transition to
medium- or large-sized companies is the tendency for capital
to gravitate towards greater profit. You find you don't have
the option of sacrificing profit for quality, often not
because customers won't buy, but because capital ups sticks
and marches off to greener pastures, leaving you insolvent.

As Marx pointed out; if you're not moving forward, you're
moving back. There is no comfortable half way.

None of which quite follows your comment...oh well.

cheers, Ian





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"Tynan AgviŠr" wrote in message
. 3.70...
" Don't be swayed by charm. It is possible that an
offensive
and socially inept lout could be the best man for the
job,
although possibly not this particular one.



I dont think they are charming(yet). They simply gave me
and my question
respect and were helpful. They did not clutter up the
thread with negative
nonsense. These days, if someone is simply respectful,
hell , that is
enough to make them stand out..a lot of folks dont have a
"catch stupid,
disrespectful, and unnecessary statments" filters between
their brains and
their mouths/fingers. I admire the ones who do.

Well, the ability to show respect and not act like an ass
counts for a lot
with me. If my dumb carcass (I grew up on the wrong side
of the tracks
surrounded by white trash and oxygen thieves) can learn to
be civil long
enough to get through the army infantry school, sfas, and
ranger school,
and manage to keep my ass glued on long enough to get
through Iraq and an
honorable discharge..anyone can. Anyone! I always ask
myself "Is what I am
saying helpful or pertinent?" "am I being respectful or
not?" Basic human
respect. People that cant pull themselves together and be
decent long
enough to do a business transaction dont deserve
breathe..much less to make
money off others.


Such virtue. Well done.

Ian


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Tynan AgviŠr wrote:

Perhaps you missed the word "recreational" in the
newsgroup
title?

Don't let me put you off, but I find your whole approach
tacky and foolish.

What have you contributed here, parasite?

Top posted in utter disdain.


Skirting the issue of name calling..


It was, at the time of writing, an accurate description.
Some parasites are nice and symbiotic, BTW. Tacky is your
own word, and foolish expresses an honest opinion. I'm
trying to help, but you make me feel rejected. I fear you
don't respect me, and that makes me sad. Sob.

I havent claimed to be of any
consequence to this group. I am just a musician and part
time recording
engineer who loves the sound of tube gear. Noting the
volume of the posts
here, and at reccomendation of one of my good friends, I
figured I would
drop a line and see if someone could steer me in the right
direction. Why
that gives some of you sand in your vaginas I have no
idea. Normally when
People post to groups I am a part of and are looking for
engineers, and I
am a good fit, I jump at the chance. I certainly dont
whine and try to
discourage people from seeking my (or anyone elses)
services..In this age
of DIY I recognize the value of those who still need the
services of audio
veterans. This thread has left me a bit confused and more
than a little
amused.


Glad to be of service.

Graham, Rudy , Andre and others..thanks for keeping this
on track(while
managing to spar with Mdme Ian, impressive)


Only Eeyore and you have sparred with me. That's OK, I can
cope with being picked on.

I raised the issue of voicing, which seemed to me a positive
move, considering the rest is plain engineering.

Relations here are about history, obviously. Once bitten
twice shy, as I am sure Patrick would agree. He would
probably do you a first class job, or could make a
contribution on the basis of much experience, but you might
have put him off with your pomposity.

Whingers can be gurus too.

Ian


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PS, have you seen this:

http://www.vintec-audio.de/vintec/index_E.htm

!

Ian


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Eeyore wrote:


robert casey wrote:


But there's a time delay in getting that feedback signal to the input



WRONG again.

Oh, maybe 20uSec, but maybe not worth worrying about?
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Default Which tube expert can do custom works?



Then you try to cancel that all out with the feedback



That's NOT how feedback works (in some sequential manner). You should learn
something about proper feedback theory.


Well, there is some propagation delay of the signal as it works its way
thru a real op-amp. Music signals are full of transient spikes and
such, not just continuous sine waves. This propagation delay doesn't
seem to be specified or even presented in most datasheets. But looking
at a somewhat randomly chosen op-amp
http://focus.ti.com/lit/ds/symlink/opa244.pdf
on page 9 there's an oscilloscope "picture" of the "small signal step
response". The op-amp is set to unity gain, the output has an overshoot
of about 2uSec duration. That would be the period of time the signal
took to get from input to output, and thus how long it took for the
feedback loop to see it and apply it to the other input of the op-amp.
And to correct the overshoot. Sure, that's not much time, about a half
cycle of 250KHz, and okay, that's probably fast enough of a response for
audio work. But if it was say 200uSec, that would be a period of time
for a cycle of 5KHz and a period of time that the feedback loop isn't
doing anything, and you'd have audible overshoots, and it would sound
pretty bad. Fortunately most op-amps are way better than that, but I
mention this excessive case to demo this point. Of course I may be
worrying about something that doesn't normally matter, and thus I may
well be full of Total and ABSOLUTE ********... :-)

Sure, if you had an amp that had zero propagation delay, then feedback
would be immediate and what I mentioned about the feedback loop having
to clean up secondary crud would go away.

You get a similar effect with vacuum tube audio amps with the global
feedback loop. There is a time delay (aka propagation delay) for the
signal to get from input to output. This is also expressed as phase
shift, and it gets bigger for higher frequencies. There's some high
audio frequency where this phase shift hits 180 degrees. And that makes
normally negative feedback go positive, and it could go into
oscillation, so you build the feedback circuit in such a way that it
gives no feedback up at such high frequencies.


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Eeyore Eeyore is offline
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Ian Iveson wrote:

Eeyore continued:

It seems that Tynan AgviŠr isn't fooled by your
posturing.


Why should I care, why should I posture, and quite what
posture do you believe I have adopted?

Submit a sample schematic of a valve circuit of your design.
Let's see what you can really do.


A typical triode stage requires a grid, anode load and cathode resistor
(possibly 'bypassed'). What is there to 'design' ? Choosing a resistor
value ?

The thing is that tube circuitry is astonishly formulaic. Designing with
transistors is anything but.


Graham

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Ian Iveson wrote:

Relations here are about history, obviously. Once bitten
twice shy, as I am sure Patrick would agree. He would
probably do you a first class job, or could make a
contribution on the basis of much experience,


Patrick has AFAIK absolutely ZERO experience of pro-audio recording
equipment.


but you might have put him off with your pomposity.


LOL ! You're quite clueless.

Graham

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robert casey wrote:

Eeyore wrote:
robert casey wrote:

But there's a time delay in getting that feedback signal to the input



WRONG again.


Oh, maybe 20uSec, but maybe not worth worrying about?


You think that the open-loop bandwidth of a typical op-amp is only 50kHz ?
LMAO !

Try 55MHz for the LME49710 and around 10 MHz for more pedestrian offerings.

It's NOT a *time* delay either.

Graham




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Eeyore Eeyore is offline
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robert casey wrote:

Then you try to cancel that all out with the feedback


That's NOT how feedback works (in some sequential manner). You should learn
something about proper feedback theory.


Well, there is some propagation delay of the signal as it works its way
thru a real op-amp.


NO !

This is audiophoolery nonsense. There are risetimes and the like for sure JUST
LIKE TUBE CIRCUITS but that is not 'propagation delay'.

Propagation delay is a figure that's relevant to digital (switching - typically
saturated switching) circuits not analogue ones and is totally irrelevant to
audio signals.

Graham

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robert casey wrote:

Music signals are full of transient spikes and such,


More audiophool nonsense.


not just continuous sine waves. This propagation delay doesn't
seem to be specified or even presented in most datasheets.


Propagation delay is not relevant to op-amps. That's one reason you won't find
it. It's a figure associated with logic gates and the like and is a consequence
of (typically) saturated switching circuits with their attendant storage times.
One reason that ECL logic of old was so fast in comparison to TTL in the olden
days was that is was NON-saturated switching and therefore avoided storage time
delays.

Op-amps do not saturate unless overdriven (clipped).


But looking at a somewhat randomly chosen op-amp
http://focus.ti.com/lit/ds/symlink/opa244.pdf
on page 9 there's an oscilloscope "picture" of the "small signal step
response". The op-amp is set to unity gain, the output has an overshoot
of about 2uSec duration.


MUSIC does not contain very short rise time 'steps' as desribed there. Therefore
this is completely irrelevant.

The fastest 'transient' in music is probably of around 100usec risetime. This is
'forever' to a modern op-amp.

You need to learn something of value about electronics. At present you're
misapplying and misunderstanding everything.

Graham



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robert casey wrote:

Sure, that's not much time, about a half
cycle of 250KHz, and okay, that's probably fast enough of a response for
audio work.


Where are the 250 kHz signals in audio ?


But if it was say 200uSec, that would be a period of time
for a cycle of 5KHz and a period of time that the feedback loop isn't
doing anything


More COMPLETE NONSENSE. Feedback is a CONTINUOUS linear process. It is NOT
'delayed'. This is basic 'electronics 101'.

Also, analogue audio uses LINEAR circuits NOT switching ones. You're getting very
mixed up.

Graham

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RdM RdM is offline
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Default Which tube expert can do custom works?

"Ian Iveson" in
yonder.co.uk:
Eeyore blethered:

I would probably trust Rudy, BTW, and a couple of others
round here least given to self-aggrandising delusions.


Oh right. You'd dismiss the only pro-audio design engineer
posting here.

Your rampant amateurism knows no bounds.


Indeed not. I'm proud to be an amateur, and happy to know no
bounds. Being rampant is icing on the cake.

Unlike your failed products, bounded firstly by failure in
the market, and then by the ruin of your employer.

You have trumpeted your ignorance here for long enough for
most to know the truth. Let's see who jumps to your defence.

Ian


Hey personally I find Graemes points of view refreshing & not unknowledgeable.
Er, Graham's ... a twist of
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flipper wrote:

Eeyore wrote:
robert casey wrote:

Sure, that's not much time, about a half
cycle of 250KHz, and okay, that's probably fast enough of a response for
audio work.


Where are the 250 kHz signals in audio ?


But if it was say 200uSec, that would be a period of time
for a cycle of 5KHz and a period of time that the feedback loop isn't
doing anything


More COMPLETE NONSENSE. Feedback is a CONTINUOUS linear process. It is NOT
'delayed'. This is basic 'electronics 101'.


It's continuous, as long as one ignores quantum mechanics, but there
are no known 'instantaneous' processes of any kind.


Navel gazing has nothing to offer this thread.

Perhaps you'd like to examine how many quanta are involved.

Graham

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Ian Thompson-Bell Ian Thompson-Bell is offline
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Eeyore wrote:

Ian Thompson-Bell wrote:

Eeyore wrote:
Oh right. You'd dismiss the only pro-audio design engineer posting here.

And who would that be, then?


Are you claiming to be active in this field still ? Did you do design ? I
honestly don't know. You're not a regular enough poster for me to know that
much about you.

Graham


I was simply asking who *is* the only pro-audio designer posting here?

Cheers

Ian
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Ian Thompson-Bell Ian Thompson-Bell is offline
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Ian Iveson wrote:
PS, have you seen this:

http://www.vintec-audio.de/vintec/index_E.htm

!


What are the 'SQ' tubes mentioned on this site?

Ian


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Patrick Turner Patrick Turner is offline
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John Byrns wrote:

In article ,
Patrick Turner wrote:

Using tubes only is all you need, and its not a very complicated
matter for design unless you want lots of bells and whistles such as
tube based
12 band graphic eq to each input channel, and all floating balanced
inputs and balanced outputs.


Tubes easily did the floating balanced inputs and outputs thing by
making use of transformers. 12 band graphic equalizers are child's play
with tubes. A much more serious challenge would be to design a tube
based parametric equalizer. If anyone has a reasonable idea for how to
approach the latter please let me know as I would like to pursue it.


Gee, if what you say is just so easy and simple, I'd hate to see your
idea of complexity.
But yes, floating outs and ins is very well done with transformers,
that's for sure.

But using output and input trannies IS complex compared to using none at
all.

And for each band is not one triode needed? 12 bands for each input
channels adds up
to a huge box of tubes....

I have no idea where a tubed parametric schematic can be located.

Patrick Turner.

Regards,

John Byrns

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Patrick Turner Patrick Turner is offline
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"Tynan AgviŠr" wrote:

All I am saying is that experts normally want some sort of
"professional" fee,
ie, more than what you'd pay a cleaner.
And you have not indicated what you are prepared to pay.

Doing such design work takes considerable time.

If you really want something done, and done right,
and in a good time frame, make a deal nobody can refuse.

I'm extremely busy for the next 6 months can't help you
right now.

Does not Manley Labs have something you might purchase off the shelf?

Patrick Turner.


Ok, sure I expect that most people require a fee..but I generally dont
talk about money on public newsgroups. That is pretty tacky in my
opinion.


You are quite entitled to your opinion.

And I will die 1,000 death's defending your right to free speach,
but if I disagree with you its not a big deal, eh?

My parents tried to tell me I mustn't discuss Sex, Politics, Religion at
the dinner table.

But they are my favourite subjects, and I get bored with small talk,
or the prices of houses and groceries.

So money talk here in this "Anything Goaz" Internet isn't out of place
imho....


On top of that..I dont know what a project like that would go
for because nothing like that exists!


Something like what you want is much more complex than a normal preamp,
and its a one-off, so expect the price to be several times whatever
range of
preamp prices you see, so maybe between $1,000 and $5,000.




Ive seen a lot of talk about money,
but normally when I get audio work done(I get a lot of microphone
modifications, for example), I tell the two techs that I deal with mainly
what I am looking for, they do research, give me cost scenarios, and
that's that. Why would I come on here, like an idiot, say "hey, I am a
dumbass numbnuts who doesnt know anything about nothing", "ive got XXXX.
dollars here, and I want someone to build me a mixer." "Who can do it?",
..Nothing about that seems smart.


But what if you end up having a lot of us argue about the best way to do
it
for a month and you have only $500 to spend?

What's in it for any of us?

Ive never done business that way, and
dont intend on ever doing it that way.


I think everyone here would realise that you would negotiate privately
about the actual agreed sum if you wanted to.

I had hoped someone would contact
me(and they have) , do a little brain storming with those expert brains
of theirs, get back to me with a figure and some scenario of what they
could do, yadda yadda. And lets work it out.. as for the things you
said.. *ive* never known any expert do do business in that manner.


To prepare a prospective schematic neatly drawn up in MS paint is a full
day or two's work,
but I ain't got time now.

Maybe someone else has the time and will go all public about the design
to give the
whole world something, not just have you being the sole beneficiary of
the work.

You may not actually end up buying anything. Many people are saying thay
want this or that
and want to pay for it but after lots of discussion they get nothin.
Shop assistants call them tyre kickers.


dont want to approach this like an auction or a contract to build a
prison. I want someone to talk to me one on one and work with me. Ive had
4 guys offer very helpful information(helping me narrow down what I want,
and believe me I appreciate it very very much), but outside of those guys
(thanks be to them again), i hear a lot of talk about money, but no talk
about what someone could offer. do people really think that way?? "Give
me money and we can talk!"..if so that is bull****!..Hell, how do I know
you aren't some Schizo in Dorothea Dix or Joe Blow from
piscopo..hell...or that you know your 3rd point of contact from a hole in
the ground?
Obviously you cant help, Mr. Turner.. thats cool..but I did want to
answer your questions.

As for manley..Well, I dont need anything as large as what they offer,
and they dont do anything smaller...they are pretty much on the verge of
"mass production" , and I want something that is mine(and the builders)
alone.


Yup, you get printed circuit boards double sided, and often a schematic
that could have been better
but its in a nice box and will tend to keep its value awhile....

The custom job won't have a printed circuit board.

It will be all point to point wiring, proper chassis,
and built up to a standard, not down to a price....
Such things are never cheap.

Ill keep hoping, maybe theyll come along.



Well let's see if you get your design fully fleshed out for nothing.

Men are men and likely to argue endlessly so long about how to do it
right....

And we don't have the ability to post schematics right here and the
groups which do allow
schematics posted are not accessable by everyone.

Meanwhile I have real work to perform or I starve.

Patrick Turner.
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"robert casey masturbating audiophool TROLL "


Though I'm not enough of a mathematician to rigously express it,

my gut feeling



** Not really any way to do science or engineering.

Gut feelings are what primitive man used instead of "science", as did the
Alchemists, all manner of fakers and charlatans - and now that the human
race knows better - complete * ****wits * like you come along and want
to drag us all back to the pig ignorance of the Dark Ages.


is that op-amps with the tons of negative feedback
is not a great device for audio work. Non-linearities will create
harmonics and intermodulation products. Then you try to cancel that all
out with the feedback, but as you may cancel most of the lower order crud,
you then create even more higher order harmonics and intermodulation
products. And that loops back yet again.



** Total and ABSOLUTE ******** !!!!!!!!!!!!!!!!!

You criminal ass.




....... Phil






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"robert casey masturbating audiophool TROLL "


Though I'm not enough of a mathematician to rigously express it,

my gut feeling



** Not really any way to do science or engineering.


Gut feelings are what primitive man used instead of "science", as did the
Alchemists, all manner of fakers and charlatans - and now that the human
race knows better - complete * ****wits * like you come along and want
to drag us all back to the pig ignorance of the Dark Ages.



is that op-amps with the tons of negative feedback
is not a great device for audio work. Non-linearities will create
harmonics and intermodulation products. Then you try to cancel that all
out with the feedback, but as you may cancel most of the lower order crud,
you then create even more higher order harmonics and intermodulation
products. And that loops back yet again.



** Total and ABSOLUTE ******** !!!!!!!!!!!!!!!!!

You criminal ****ing ass !!!!!!!!





....... Phil






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John Byrns John Byrns is offline
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In article ,
Eeyore wrote:

Ian Iveson wrote:

Eeyore continued:

It seems that Tynan AgviŠr isn't fooled by your
posturing.


Why should I care, why should I posture, and quite what
posture do you believe I have adopted?

Submit a sample schematic of a valve circuit of your design.
Let's see what you can really do.


A typical triode stage requires a grid, anode load and cathode resistor
(possibly 'bypassed'). What is there to 'design' ? Choosing a resistor
value ?


That's a lot more complex than designing with op=amps today where there
is nothing to choose, where you don't even need to pick values for the
"anode load and cathode resistor (possibly 'bypassed')."

The thing is that tube circuitry is astonishly formulaic. Designing with
transistors is anything but.


OK, that may be true of designing with transistors, but designing with
op-amps is considerably more formulaic even than designing with tubes.

Graham, you claim to have been a "pro audio designer", why don't give
all of us who haven't worked as "pro audio designers" a tutorial on
designing mixing networks? By mixing networks I mean the part of a
"mixer" that does the actual mixing of the multiple inputs. The design
of the various amplifiers that are required in a project like this is
not beyond the capability of many in this group, but the actual "mixing"
network and its requirements is a different matter. As a "pro audio
designer" please enlighten us about this aspect of "mixer" design.


Regards,

John Byrns

--
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