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  #41   Report Post  
Ruud Broens
 
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"Robert Casey" wrote in message
...
:
:
: The PROVEN, perceived sound quality of audio circuits with flat
response
: and inaudible levels of THD is "perfect sound". "Perfect sound " = no
: audible alteration in perceived sound when bypassed.

Pray, tell, how you equate perceived with proven--


: therefore THD is *not* indicative for the sound quality,
:
:
:
: ** Based on a false premise - hence a false conclusion.

the premise being what ?
:
: Maybe my ears are defective, but I find that:
: (close to 0% distortion) = best sound,
: A little 2nd harmonic up to -40dB down and no more than -50dB 3rd
: sounds pleasant,
: More than -50dB of 3rd = yuck.
:
and how did you establish that ? using a quasi-musical test signal
and analysing the distortion in that ? there is simply too much
going on, and much as some would like it, saying a model is
more true than reality is just nonsense.

: It -might- be more meaningful to compare amps by looking at specs
: specifying how much 2nd H, how much 3rd H, etc listed separately.
: An amp with say -40dB 2nd and -50dB 3rd is likely to sound
: better than one with -50dB 2nd and -40dB 3rd. But both will
: have the same THD spec (yes?).
:
still only marginal - please try to study perception in some depth
and maybe you'd see number games don't say much. Won't pursue
that any further, as it would probably lead to OT flaming by persons
who don't have a clue but do have a firm belief...

:
: But then, many a thousand pro-tube processing and mixing gear
: must be bought by fools... ?
:
:
: Maybe the issue is that tubes are said to permit larger transient sounds
: thru without
: hard clipping, vs op-amp designs. But that might not mean much as the
: recording
: device will likely clip that transient anyway.

Well, no maybe's there, NO opamp will even get close to 70 V rms
levels, for sure. What rec. device are you referring to, specifically ?

Happy speculating,
Rudy


  #42   Report Post  
Ruud Broens
 
Posts: n/a
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"Kevin Aylward" wrote in message
...
: John Woodgate wrote:
: I read in sci.electronics.design that Kevin Aylward
: kevindotaylwardEXTR wrote (in
: .net) about 'A little
: feedback worse than none at all?', on Tue, 18 Nov 2003:
:
: As I explained, none of this matters with *large* amounts of
: feedback. Large feedback will clobber all distortion. You wont here
: it if is all below 0.01%, and this is easy to do. End of story.
:
: This is simply not true,
:
: Yes it is.
:
: as has been found time after time by people
: who thought that 60 dB of feedback would cure all ills.
:
: It most certainly does, if it is applied correctly. That means that
: there is 60 db, i.e. if it is slew limiting than the feedback aint 60db,
: it goes to zero, hence violates the assumption of 60db of feedback.
:
: When you look
: at the IM distortion, that 0.01% is a sick joke.
:
: Rubbish. Complete and utter crap. What drugs are you on? For starters,
: consider the FM distortion of speakers. i.e. consider a 1khz signal
: riding on a speaker going back and forth at 100 Hz. 0.05 to 0.1% plus
: dopplar induced distortion is easily achievable.

Well, you don't exactly show clarity of mind here yourself, do you ?
Please rephrase and explain what this has to do with the sentence above..
And since you seem to be a numbers-believer, please tell us how you
arrived at them

And this is really
: nasty stuff. Its a spread right across the spectrum.

Wow! Now, let's see, a large cone excursion, say 10 mm, creates a
doppler-frequency shift of ?? numbers, please..

Adding in the
: standard 1% to 10% of normal speaker THD/IMD, and there is no chance
: whatsoever that your claim is supported.
:
: There is no way that one can audiable detect 0.01% THD/IMD levels from
: correctly designed amps. If it was frequncy shifts, maybe, but not
: distortion. Been there done, it, wrote the book.
:
: Kevin Aylward
:

:
http://www.anasoft.co.uk
: SuperSpice, a very affordable Mixed-Mode
: Windows Simulator with Schematic Capture,
: Waveform Display, FFT's and Filter Design.
:
: http://www.anasoft.co.uk/replicators/index.html
:
: Understanding, is itself an emotion, i.e. a feeling.
Says who ?

: Emotions or feelings can only be "understood" by
: consciousness.

Sorry, read up on cognitive science and logic and
....a whole lot more...
this is just posing without any apparent insight, Kevin.

"Understanding" consciousness can
: therefore only be understood by consciousness itself,
: therefore the "hard problem" of consciousness, is
: intrinsically unsolvable.
:
: Physics is proven incomplete, that is, no
: understanding of the parts of a system can
: explain all aspects of the whole of such system.

That transposing Goedels findings on mathematical
theory on the domain of physics - your idea ?
:
****ed off by posers,
Rudy


  #43   Report Post  
Phil Allison
 
Posts: n/a
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"Ruud Broens"

"Robert Casey"
:
:
: The PROVEN, perceived sound quality of audio circuits with flat
response and inaudible levels of THD is "perfect sound". "Perfect sound

" = no
: audible alteration in perceived sound when bypassed.

Pray, tell, how you equate perceived with proven--



** You need to pay more attention Ruud - as well as learn to think
rationally and buy yourself a dictionary.

The above was written by Phil Allison.


BTW: Perceived means experienced by the senses while "no audible
alteration" is proved is when using scientific test procedures the outcome
of a listening test shows no detection of a specific change.



........... Phil










  #44   Report Post  
Ruud Broens
 
Posts: n/a
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"Ian Iveson" wrote in message
om...
: OTOH, until we know what you are trying to achieve, it is hard to
: help.
:
: There are a heap of considerations here, concerning where and how the
: mixing is done, and from and to where the feedback might go.
:
: AFAIK, your original concerns were relevant in a different context and
: may not be applicable here.
:
: Have you considered simulation? With spice you can get a reasonably
: accurate comparison of topologies, with their characteristic
: distortion and frequency responses.
:
: Several folk hanging out on rat use circuitmaker, and there are a
: range of valve models available. Certainly there is no shortage of
: models for such as ECC8X and EF86. You do need to find one with enough
: sophistication to reasonably approximate the distortion.
:
: Your plan seems reasonable to me, and clear in outline. One obvious
: question though: if it were possible to take your kind of short-cuts
: to console design in the 50s, why didn't they do it?
:
: If you take your feedback from the output of the white cathode
: follower, you will have a ring of three, which is a classic circuit
: for some reason I can't remember. Have you considered mu-followers for
: the gain stages, or perhaps just for the second? If allowable you
: could achieve such by using MOSFETS for the top devices.
:
: cheers, Ian

Yep, that could 'shave the bill', second stage will have large
voltage swing, little mosfet background noise won't hurt

Can't beat solid state noise-wise, no question. But you can
emulate the strategy to a certain extent, that is, use a 'massively'
parallel device approach, massive being in practical terms: 4.
Cheaper than 2 EF86's paralleled by quite a bit would be 4
Telefunken or Siemens C3m's ,triode-strapped, which would
give you about 60* amplification at about the same levels
as the EF86's, probably somewhat higher distortion (have
no data readily available, just the curves) and requiring a
'meetier' current source on top.
No data on noise, but as they were developed for long-
distance repeating of signals, low-noise was 'in by design'.
Worth a try, maybe, coz' these german telecom's tubes are just
now appearing on the market, in abundance it seems - hence
to good to be true pricing

Keep up 'the quest' ,
Cheers,
Rudy


  #45   Report Post  
Ruud Broens
 
Posts: n/a
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Hehe, when Al get's passionate,
there's nuthin'stoppin'him
Rudy

"Choky" wrote in message ...
: Whoa !
: Long Post!
: )
:
: --
: --
: .................................................. .......................
: Choky
: Prodanovic Aleksandar
: YU
:
: "don't use force, "don't use force,
: use a larger hammer" use a larger tube
: - Choky and IST"
:
; - ZM
:: Happy Ears!
: Al
:
:
: Alan J. Marcy
: Phoenix, AZ
:
: PWC/mystic/Earhead
:
:




  #46   Report Post  
Patrick Turner
 
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Default



NewYorkDave wrote:

Now, it should be apparent why my original post included the phrase:

"Please, let's ignore for the moment the question
of WHY someone would want to design a tube mixing console in 2003!"

The discussion was pretty constructive up to the point that I revealed
my rerasons for wanting to build a tube mixer. Now the ad-hominem
attacks have begun. Without knowing anything about me, two posters
have seen fit to call me "deluded" and "a fool on a fool's quest." But
to the rest of the posters, I thank you for your constructive
criticism and the ideas you've offered.


There are those who wouldn't use a tube to do anything, ever,
in any circuit.
I am not one of them, and I build with SS and tubes, and
I enjoy both methods of signal handling.

I know folks who like tube gear in their studios, and there is no
need for an argument about which is better, or even legitimate.

So, where were we?

Tube design for a mixing desk. Its sounds like a great project idea.

I suggest you post only to rec.audio.tubes, and
not also to sci.electronics.design, where perhaps some of the anti tube
brigade
will pester you.

Your first post on the matter seemed to present a daunting task for us to
design for you,
but it would be easier if you had an easy to understand block diagram,
with the amps shown as triangles, with the required gain drawn in,
and the attenuator impedances.

Its then we could advise on a suitable amp config.

Patrick Turner.


  #47   Report Post  
Patrick Turner
 
Posts: n/a
Default



Jon Yaeger wrote:

I dunno . . . . most SS stuff I've heard with wonderfully low THD, IM, etc.
doesn't sound as good to my ears as some 1% distorting tube sets . . .

Simplicity is a good goal. In my experience, less complexity means less
chance of failure, and sometimes lower noise.

Golden ears may be a delusion, but it's often a pleasant and rather harmless
one . . .


Indeed,

But Hey Dudes! this thread has gone on as a cross poster.
I am just letting you all know I am posing a reply back to
rec.audio.tubes only.

I am just letting you know.

Patrick Turner



From: "Kevin Aylward"
Organization: AnaSoft
Reply-To: "Kevin Aylward"
Newsgroups: rec.audio.tubes,sci.electronics.design
Date: Tue, 18 Nov 2003 07:29:20 -0000
Subject: A little feedback worse than none at all?

NewYorkDave wrote:
I apologize for not providing more detail in my original post. I'll
try to give a clearer explanation of what I'm trying to do. I have
only a few minutes left in my lunch hour, but I'll try to put it to
good use

I record music on an 8-track multitrack recorder, and I want to build
a tube mixing console to take the place of the IC-based model I've
been using. My goal is to achieve a clearer sound (due to a simpler
circuit with fewer active stages)


This is an old wife's tale, i.e. a complete and utter nonsense argument.
Less parts do *not* mean a clearer sound. Indeed, more stages mean you
can have less gain per stage allowing for more feedback at each stage
which reduces the distortion tremendously.

and perhaps some of that intangible
"tube warmth."


This where a dirty sound sounds better.

However, I'm not looking to build a "distortion
device"... The tube consoles that were used to track the records we
all love from the '50s and '60s were designed to be as linear as
possible within the limits of the technology of the day, and any
euphonic qualities added were incidental. It's not clear to me whether
that sound really came from the tubesand transformers or from the more
straightforward topologies, anyway. In a modern mixing console, a
signal may pass through tens of IC amplifiers on its way from input to
output.


So bloody what. A decent modern console uses op-amps with 0.005% thd
and imd. It makes no practical difference whether there are quite a few
in series, especially as explianed above. A final spec of a decent
console is easily 0.01%, 1db flat from 20Hz to 40khz.

You are suffering from a severe "golden ears" delusion.

Kevin Aylward

http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

http://www.anasoft.co.uk/replicators/index.html

Understanding, is itself an emotion, i.e. a feeling.
Emotions or feelings can only be "understood" by
consciousness. "Understanding" consciousness can
therefore only be understood by consciousness itself,
therefore the "hard problem" of consciousness, is
intrinsically unsolvable.

Physics is proven incomplete, that is, no
understanding of the parts of a system can
explain all aspects of the whole of such system.



  #49   Report Post  
Kevin Aylward
 
Posts: n/a
Default

Ruud Broens wrote:
"Kevin Aylward" wrote in
message ...
John Woodgate wrote:
I read in sci.electronics.design that Kevin Aylward
kevindotaylwardEXTR wrote (in
.net) about 'A little
feedback worse than none at all?', on Tue, 18 Nov 2003:

As I explained, none of this matters with *large* amounts of
feedback. Large feedback will clobber all distortion. You wont here
it if is all below 0.01%, and this is easy to do. End of story.

This is simply not true,


Yes it is.

as has been found time after time by people
who thought that 60 dB of feedback would cure all ills.


It most certainly does, if it is applied correctly. That means that
there is 60 db, i.e. if it is slew limiting than the feedback aint
60db, it goes to zero, hence violates the assumption of 60db of
feedback.

When you look
at the IM distortion, that 0.01% is a sick joke.


Rubbish. Complete and utter crap. What drugs are you on? For
starters, consider the FM distortion of speakers. i.e. consider a
1khz signal riding on a speaker going back and forth at 100 Hz. 0.05
to 0.1% plus dopplar induced distortion is easily achievable.


Well, you don't exactly show clarity of mind here yourself, do you ?


You mean, you don't have the capability to work out the details for
yourself?

I was posting to John, he is well aware of how to calculate Doppler
frequency shifts. For the most part, John is a very good engineer. He
just makes some mistakes like we all do.

Please rephrase and explain what this has to do with the sentence
above.. And since you seem to be a numbers-believer, please tell us
how you arrived at them

And this is really
nasty stuff. Its a spread right across the spectrum.


Wow! Now, let's see, a large cone excursion, say 10 mm, creates a
doppler-frequency shift of ?? numbers, please..


And you have the cheek to criticize my ideas below, with this
demonstration of your lack of knowledge here.

velocity = f.x = 100 x 0.01 = 1 m/s

Sound travels at 330 m/s

df/f = v/330 = 1/330 = 0.3%


(technically the velocity don't change, but the effect is the same via
wavelength)


Adding in the
standard 1% to 10% of normal speaker THD/IMD, and there is no chance
whatsoever that your claim is supported.

There is no way that one can audiable detect 0.01% THD/IMD levels
from correctly designed amps. If it was frequncy shifts, maybe, but
not distortion. Been there done, it, wrote the book.



http://www.anasoft.co.uk/replicators/index.html

Understanding, is itself an emotion, i.e. a feeling.

Says who ?


Your serious dude? Its trvial. See below.


Emotions or feelings can only be "understood" by
consciousness.


Sorry, read up on cognitive science and logic and
...a whole lot more...


Clearly, I know a lot more than you about this subject.

If you think that you can experience an emotion without consciousness,
please explain, in detail.


this is just posing without any apparent insight, Kevin.


Nonsense. The fact that you don't have the insight to understand this,
is your problem, not mine. This is something I actually know quite a bit
about, as will be clear from the following in this post.

Please explain to me how you actually *perceive* an emotion *without*
consciousness? Its a tautology. Its that simple. Consciousness is *how*
feelings are recognised, i.e. how emotions are recognised. Emotions are
feelings, i.e. we are consciously aware of them.

What do you think "understanding" *really* is dude. Jump out of the bath
in excitement and say "Eureka, I've got it!!!" Then you will understand
that "understanding" is an emotion, i.e. a *feeling* that you
*experiance*. "Ahh haaa, now... I *understand*". Say this in you mind to
make it sink in.

The fact that you have never understood this before, don't make it any
less so. A feeling is what consciousness is all about. How you can not
understand the most basic of these concepts, and spout off gibberish
like this, is simply amazing.

What the issue here is, is that many may well have missed the obvious.
Go back and really *think* on what "feelings" "awareness" "emotions"
"consciousness" really are. They are all self referral. You cannot
explain any, without invoking the other. For some reason, many have
missed this fundamental point, and have spent much effort in trying to
derive consciousness.


"Understanding" consciousness can
therefore only be understood by consciousness itself,
therefore the "hard problem" of consciousness, is
intrinsically unsolvable.

Physics is proven incomplete, that is, no
understanding of the parts of a system can
explain all aspects of the whole of such system.


That transposing Goedels findings on mathematical
theory on the domain of physics - your idea ?


Goedel is a *general* existence proof. It does not allow one to actually
show that a *specific* relation is non derivable, only that such
relations exist. My argument proves an actual example. I have shown that
an understanding of consciousness *cannot* be derived from inanimate
processes. Its a new axiom. This is indeed already *accepted* by the
likes of Roger Penrose as a basic new axiom. I have simple *proved* that
this *is* the case.

This has been missed because many like you, did not appreciate what
"Eureka!!!! I understand" really meant. That is, understanding is indeed
an emotion, as it is something one feels, despite the fact that many
have not recognised this before. Secondly, in my proof, the term
"emotion" can be dispensed with anyway. It is not important to the
proof. It was only included to clarify the issue. All that matters is
that "understanding" is something that we are consciously *aware* of. If
we are *not* consciously aware of something, than how can we have an
understanding of something? So, since being aware that we understand
something necessarily requires consciousness, therefore, its self
referral. Therefore, we cannot derive an understanding of consciousness
without invoking consciousness in the explanation.


****ed off by posers,


You mean, ****ed off by people who understand much, much, more than you.
If you do have any *valid* objections to
http://www.anasoft.co.uk/replicators/index.html, let us here them.

Kevin Aylward

http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

http://www.anasoft.co.uk/replicators/index.html

Understanding, is itself an emotion, i.e. a feeling.
Emotions or feelings can only be "understood" by
consciousness. "Understanding" consciousness can
therefore only be understood by consciousness itself,
therefore the "hard problem" of consciousness, is
intrinsically unsolvable.

Physics is proven incomplete, that is, no
understanding of the parts of a system can
explain all aspects of the whole of such system.


  #50   Report Post  
Ruud Broens
 
Posts: n/a
Default


"Kevin Aylward" wrote in message
...
:
: When you look
: at the IM distortion, that 0.01% is a sick joke.
:
: Rubbish. Complete and utter crap. What drugs are you on? For
: starters, consider the FM distortion of speakers. i.e. consider a
: 1khz signal riding on a speaker going back and forth at 100 Hz. 0.05
: to 0.1% plus dopplar induced distortion is easily achievable.
:
: Well, you don't exactly show clarity of mind here yourself, do you ?
:
: You mean, you don't have the capability to work out the details for
: yourself?
:
: I was posting to John, he is well aware of how to calculate Doppler
: frequency shifts. For the most part, John is a very good engineer. He
: just makes some mistakes like we all do.
:

Well, if you must refrain to personal remarks (allways a sign of weakness,
lack of 'quality arguments') , John is a very good engineer at least sounds
a lot nicer than What drugs are you on ?..
:
: Wow! Now, let's see, a large cone excursion, say 10 mm, creates a
: doppler-frequency shift of ?? numbers, please..
:
: And you have the cheek to criticize my ideas below, with this
: demonstration of your lack of knowledge here. ????
:
: velocity = f.x = 100 x 0.01 = 1 m/s
:
: Sound travels at 330 m/s
:
: df/f = v/330 = 1/330 = 0.3%
:
:
: (technically the velocity don't change, but the effect is the same via
: wavelength)

very technical...just a small question the how does the sine wave
driving the cone translate to a constant cone velocity, please tell us..

: Adding in the
: standard 1% to 10% of normal speaker THD/IMD, and there is no chance
: whatsoever that your claim is supported.

standard 1 to 10 % - what a wild, sweeping, unqualified and therefore
utterly
nonsensical statement. hope you're not responsible for 'upcoming'
spice speaker models at the company there...

: There is no way that one can audiable detect 0.01% THD/IMD levels
: from correctly designed amps. If it was frequncy shifts, maybe, but
: not distortion. Been there done, it, wrote the book.

The book title and ISBN # being ?

: http://www.anasoft.co.uk/replicators/index.html
:
: Understanding, is itself an emotion, i.e. a feeling.
: Says who ?
:
: Your serious dude? Its trvial. See below.
:
:
: Emotions or feelings can only be "understood" by
: consciousness.
:
: Sorry, read up on cognitive science and logic and
: ...a whole lot more...
:
: Clearly, I know a lot more than you about this subject.
Wow, stating that clearly makes it so...
:
: If you think that you can experience an emotion without consciousness,
: please explain, in detail.
:
:
: this is just posing without any apparent insight, Kevin.
:
: Nonsense. The fact that you don't have the insight to understand this,
: is your problem, not mine. This is something I actually know quite a bit
: about, as will be clear from the following in this post.
:
: Please explain to me how you actually *perceive* an emotion *without*
: consciousness? Its a tautology. Its that simple. Consciousness is *how*
: feelings are recognised, i.e. how emotions are recognised. Emotions are
: feelings, i.e. we are consciously aware of them.

Hm, well, this is leading a bit astray, but if you want to discuss such
matters, let's start with definitions: so what is perception, Kevin ?

snipped some mo i'm clever, you don't understand "arguments"

: That transposing Goedels findings on mathematical
: theory on the domain of physics - your idea ?
:
: Goedel is a *general* existence proof. It does not allow one to actually
: show that a *specific* relation is non derivable, only that such
: relations exist. My argument proves an actual example. I have shown that
: an understanding of consciousness *cannot* be derived from inanimate
: processes. Its a new axiom. This is indeed already *accepted* by the
: likes of Roger Penrose as a basic new axiom. I have simple *proved* that
: this *is* the case.

Say it is so = formal prove of an argument ....boy, the 'new' science is
getting easy
these days..
(It think the subject of consciousness is just a bit to important to handle
in one-liners, but must confess it's interesting to see a 'numbers-man'
like yourself doubting a materialistic-mechanistic worldview)

::
: ****ed off by posers,
:
: You mean, ****ed off by people who understand much, much, more than you.

you don't seriously think that people are inclined to take up a discussion
if you *have* to refrain to these little smug remarks all the time, do u ?

: If you do have any *valid* objections to
: http://www.anasoft.co.uk/replicators/index.html, let us here them.
:
: Kevin Aylward
:
:
http://www.anasoft.co.uk
: SuperSpice, a very affordable Mixed-Mode
: Windows Simulator with Schematic Capture,
: Waveform Display, FFT's and Filter Design.

Have a spicy day, Kevin,
Rudy




  #51   Report Post  
Patrick Turner
 
Posts: n/a
Default



Ruud Broens wrote:

"Kevin Aylward" wrote in message
...
:
: When you look
: at the IM distortion, that 0.01% is a sick joke.
:
: Rubbish. Complete and utter crap. What drugs are you on? For
: starters, consider the FM distortion of speakers. i.e. consider a
: 1khz signal riding on a speaker going back and forth at 100 Hz. 0.05
: to 0.1% plus dopplar induced distortion is easily achievable.
:
: Well, you don't exactly show clarity of mind here yourself, do you ?
:
: You mean, you don't have the capability to work out the details for
: yourself?
:
: I was posting to John, he is well aware of how to calculate Doppler
: frequency shifts. For the most part, John is a very good engineer. He
: just makes some mistakes like we all do.
:

Well, if you must refrain to personal remarks (allways a sign of weakness,
lack of 'quality arguments') , John is a very good engineer at least sounds
a lot nicer than What drugs are you on ?..
:
: Wow! Now, let's see, a large cone excursion, say 10 mm, creates a
: doppler-frequency shift of ?? numbers, please..
:
: And you have the cheek to criticize my ideas below, with this
: demonstration of your lack of knowledge here. ????
:
: velocity = f.x = 100 x 0.01 = 1 m/s
:
: Sound travels at 330 m/s
:
: df/f = v/330 = 1/330 = 0.3%
:
:
: (technically the velocity don't change, but the effect is the same via
: wavelength)

very technical...just a small question the how does the sine wave
driving the cone translate to a constant cone velocity, please tell us..

: Adding in the
: standard 1% to 10% of normal speaker THD/IMD, and there is no chance
: whatsoever that your claim is supported.

standard 1 to 10 % - what a wild, sweeping, unqualified and therefore
utterly
nonsensical statement. hope you're not responsible for 'upcoming'
spice speaker models at the company there...

: There is no way that one can audiable detect 0.01% THD/IMD levels
: from correctly designed amps. If it was frequncy shifts, maybe, but
: not distortion. Been there done, it, wrote the book.

The book title and ISBN # being ?

: http://www.anasoft.co.uk/replicators/index.html
:
: Understanding, is itself an emotion, i.e. a feeling.
: Says who ?
:
: Your serious dude? Its trvial. See below.
:
:
: Emotions or feelings can only be "understood" by
: consciousness.
:
: Sorry, read up on cognitive science and logic and
: ...a whole lot more...
:
: Clearly, I know a lot more than you about this subject.
Wow, stating that clearly makes it so...
:
: If you think that you can experience an emotion without consciousness,
: please explain, in detail.
:
:
: this is just posing without any apparent insight, Kevin.
:
: Nonsense. The fact that you don't have the insight to understand this,
: is your problem, not mine. This is something I actually know quite a bit
: about, as will be clear from the following in this post.
:
: Please explain to me how you actually *perceive* an emotion *without*
: consciousness? Its a tautology. Its that simple. Consciousness is *how*
: feelings are recognised, i.e. how emotions are recognised. Emotions are
: feelings, i.e. we are consciously aware of them.

Hm, well, this is leading a bit astray, but if you want to discuss such
matters, let's start with definitions: so what is perception, Kevin ?

snipped some mo i'm clever, you don't understand "arguments"

: That transposing Goedels findings on mathematical
: theory on the domain of physics - your idea ?
:
: Goedel is a *general* existence proof. It does not allow one to actually
: show that a *specific* relation is non derivable, only that such
: relations exist. My argument proves an actual example. I have shown that
: an understanding of consciousness *cannot* be derived from inanimate
: processes. Its a new axiom. This is indeed already *accepted* by the
: likes of Roger Penrose as a basic new axiom. I have simple *proved* that
: this *is* the case.

Say it is so = formal prove of an argument ....boy, the 'new' science is
getting easy
these days..
(It think the subject of consciousness is just a bit to important to handle
in one-liners, but must confess it's interesting to see a 'numbers-man'
like yourself doubting a materialistic-mechanistic worldview)

::
: ****ed off by posers,
:
: You mean, ****ed off by people who understand much, much, more than you.

you don't seriously think that people are inclined to take up a discussion
if you *have* to refrain to these little smug remarks all the time, do u ?

: If you do have any *valid* objections to
: http://www.anasoft.co.uk/replicators/index.html, let us here them.
:
: Kevin Aylward
:
:
http://www.anasoft.co.uk
: SuperSpice, a very affordable Mixed-Mode
: Windows Simulator with Schematic Capture,
: Waveform Display, FFT's and Filter Design.

Have a spicy day, Kevin,
Rudy


Gee, what a tortuous thread, about doppler effects, distortions, Geodels,
existance, poseurs, and a whole bunch of subjectives, and it seems
the question of " A little feedback worse than none at all? "
has been chucked out the window.

But let's consider the doppler distortion.

If we have a bass-midrange driver, and we have a nice fat 100 Hz tone
applied, and we have a lower amplitude 1 kHz tone, then we must be getting
doppler distortion, ie, the percieved frequency
of the 1 kHz varies higher and lower depending on the
bass note making the cone travel to or away from us, respectively.
If we picked up the signal with a microphone close to the cone,
and used this signal as a feedback signal, how would the amp
respond to eliminate the doppler distortion?

My guess is that the amp would be steered by the FB
to make the 1 kHz change down or up to then make the 1 kHz from the speaker
have less variation in its F.
I could see that phase effects could lead to instabilities.

Meanwhile, someone playing a cello low note has the harmonics coming from the
sound
board which is wobbling at lower F, so doppler effects are inherent in
musical instruments.
But not in amplifiers.

Patrick Turner.


  #52   Report Post  
Phil Allison
 
Posts: n/a
Default


"Ruud Broens"


very technical...just a small question the how does the sine wave
driving the cone translate to a constant cone velocity, please tell us..



** You are one thick headed, PITA Dutch prick - Ruud.

Try entering "Doppler distortion" in Google - then maybe try growing
up a bit.


Adding in the
standard 1% to 10% of normal speaker THD/IMD, and there is no chance
whatsoever that your claim is supported.



standard 1 to 10 % - what a wild, sweeping, unqualified and therefore
utterly nonsensical statement.



** You are one thick headed, PITA Dutch prick - Ruud.

Your colossal ignorance is only matched by your smug arrogance.

Enough to make a Nazi blush.




.............. Phil








  #53   Report Post  
Kevin Aylward
 
Posts: n/a
Default

Ruud Broens wrote:
"Kevin Aylward" wrote in
message ...

When you look
at the IM distortion, that 0.01% is a sick joke.

Rubbish. Complete and utter crap. What drugs are you on? For
starters, consider the FM distortion of speakers. i.e. consider a
1khz signal riding on a speaker going back and forth at 100 Hz.
0.05 to 0.1% plus dopplar induced distortion is easily achievable.

Well, you don't exactly show clarity of mind here yourself, do you ?


You mean, you don't have the capability to work out the details for
yourself?

I was posting to John, he is well aware of how to calculate Doppler
frequency shifts. For the most part, John is a very good engineer. He
just makes some mistakes like we all do.


Well, if you must refrain to personal remarks (allways a sign of
weakness, lack of 'quality arguments') , John is a very good engineer
at least sounds a lot nicer than What drugs are you on ?..


Err.. John and me are arguable, friends. My comment was not at him
personally, but at what he said. What he said was crap.


Wow! Now, let's see, a large cone excursion, say 10 mm, creates a
doppler-frequency shift of ?? numbers, please..


And you have the cheek to criticize my ideas below, with this
demonstration of your lack of knowledge here. ????

velocity = f.x = 100 x 0.01 = 1 m/s

Sound travels at 330 m/s

df/f = v/330 = 1/330 = 0.3%


(technically the velocity don't change, but the effect is the same
via wavelength)


very technical...just a small question the how does the sine wave
driving the cone translate to a constant cone velocity, please tell
us..


It doesn't. This is the *peak* frequency shift. The frequency goes up
and down in a sine fashion, as the cone goes backwards and forwards. The
number is get a feel of the sort of the magnitude of the FM modulation
that occurs.


Please explain to me how you actually *perceive* an emotion *without*
consciousness? Its a tautology. Its that simple. Consciousness is
*how* feelings are recognised, i.e. how emotions are recognised.
Emotions are feelings, i.e. we are consciously aware of them.


Hm, well, this is leading a bit astray, but if you want to discuss
such matters, let's start with definitions: so what is perception,
Kevin ?


Most aspects of consciousness gets one into a self referral situation.
Perception is that which the conscious is aware of. What is
consciousness, that which can perceive things. Get the drift. I have
updated my site to address this in more detail.

http://www.anasoft.co.uk/replicators/understanding.html


snipped some mo i'm clever, you don't understand "arguments"

That transposing Goedels findings on mathematical
theory on the domain of physics - your idea ?


Goedel is a *general* existence proof. It does not allow one to
actually show that a *specific* relation is non derivable, only that
such relations exist. My argument proves an actual example. I have
shown that an understanding of consciousness *cannot* be derived
from inanimate processes. Its a new axiom. This is indeed already
*accepted* by the likes of Roger Penrose as a basic new axiom. I
have simple *proved* that this *is* the case.


Say it is so = formal prove of an argument ....boy, the 'new' science
is getting easy
these days..


Some of it is.

(It think the subject of consciousness is just a bit to important to
handle in one-liners, but must confess it's interesting to see a
'numbers-man' like yourself doubting a materialistic-mechanistic
worldview)


What are you on about. I *am* a strict materialistic-mechanic. There is
nohing more than mass-energy moving about. If you had read the title to
my papers, this would be obvious, The Mean Meme-Gene Darwinian Machine.
http://www.anasoft.co.uk/replicators/index.html

Consciousness is simple a result that occurs when systems get
sufficiently complicated. However, although it is *only* a function of
its mass-energy parts, it can not be derived from its parts. It just is.
It is an example of a Goedel system. True, but not derivable.


Kevin Aylward

http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

http://www.anasoft.co.uk/replicators/index.html

Understanding, is itself an emotion, i.e. a feeling.
Emotions or feelings can only be "understood" by
consciousness. "Understanding" consciousness can
therefore only be understood by consciousness itself,
therefore the "hard problem" of consciousness, is
intrinsically unsolvable.

Physics is proven incomplete, that is, no
understanding of the parts of a system can
explain all aspects of the whole of such system.


  #54   Report Post  
Frank Bemelman
 
Posts: n/a
Default

"Kevin Aylward" schreef in bericht
...

[snip]

Consciousness is simple a result that occurs when systems get
sufficiently complicated. However, although it is *only* a function of
its mass-energy parts, it can not be derived from its parts. It just is.
It is an example of a Goedel system. True, but not derivable.


How many boards do you need to pull out of HAL9000 before it
looses it's consciousness

--
Thanks, Frank.
(remove 'x' and 'invalid' when replying by email)



  #55   Report Post  
Phil Allison
 
Posts: n/a
Default

Pat the Turd wrote:


But let's consider the Doppler distortion.

If we have a bass-midrange driver, and we have a nice fat 100 Hz tone
applied, and we have a lower amplitude 1 kHz tone, then we must be getting
Doppler distortion, ie, the perceived frequency
of the 1 kHz varies higher and lower depending on the
bass note making the cone travel to or away from us, respectively.

If we picked up the signal with a microphone close to the cone,
and used this signal as a feedback signal ....



** Motional feedback has been done to linearise bass drivers using
accelerometers attached to the cone - loop stability is hairy but it can
be made stable over the lowest few octaves.

This does nothing to reduce Doppler effects in the driver - nothing
can.



Meanwhile, someone playing a cello low note has the harmonics coming from

the
sound board which is wobbling at lower F, so Doppler effects are inherent

in
musical instruments.


** Silly straw man argument - there is of course NO natural Dopper effect
between *different* instruments.

Also, whatever Doppler effects exists with a cello - the reproduction
system should add not one jot more.

Electrostatic speakers have way less Doppler, IM, THD and thermal
compression than cone speakers - as a result they are accused of sounding
"thin" by moronic cone speaker addicts.



........... Phil






  #56   Report Post  
Ruud Broens
 
Posts: n/a
Default


"John Woodgate" wrote in message
...
: I read in sci.electronics.design that Kevin Aylward kevindotaylwardEXTR
: wrote (in
: .net) about 'A little feedback worse than none at all?', on Wed, 19 Nov
: 2003:
: Err.. John and me are arguable, friends. My comment was not at him
: personally, but at what he said. What he said was crap.
:
: No, Kevin, it isn't. What happens when you apply lots of feedback around
: an amplifier of poor linearity is that you swap maybe 5% of low-order
: distortion (2nd, 3rd, 5th.) for 0.05% or so of every harmonic up to the
: upper band limit of the amplifier. The latter sounds FAR worse, because
: of the multiplicity of intermodulation products, some of which are much
: larger in amplitude than the adjacent harmonics.
: --
: Regards, John Woodgate, OOO - Own Opinions Only.
http://www.jmwa.demon.co.uk
: Interested in professional sound reinforcement and distribution? Then go
to
: http://www.isce.org.uk
: PLEASE do NOT copy news posts to me by E-MAIL!

Here is one problem of the concept of feedback itself:
it is all very well to model perceived physical phenomena
in a suitable mathematical form, convenient to 'get rid of'
time by using complex numbers, but

a cause-effect-feedback chain of events does not occur in zero time,
whatever your modeling might lead you to believe.
So here is one, just for Kevin:
what are you actually correcting there with a feedback signal ?

Cheers,
Rudy


  #57   Report Post  
Kevin Aylward
 
Posts: n/a
Default

Ruud Broens wrote:
"John Woodgate" wrote in message
...
I read in sci.electronics.design that Kevin Aylward
kevindotaylwardEXTR wrote (in
.net) about 'A little
feedback worse than none at all?', on Wed, 19 Nov 2003:
Err.. John and me are arguable, friends. My comment was not at him
personally, but at what he said. What he said was crap.


No, Kevin, it isn't. What happens when you apply lots of feedback
around an amplifier of poor linearity is that you swap maybe 5% of
low-order distortion (2nd, 3rd, 5th.) for 0.05% or so of every
harmonic up to the upper band limit of the amplifier. The latter
sounds FAR worse, because of the multiplicity of intermodulation
products, some of which are much larger in amplitude than the
adjacent harmonics. --
Regards, John Woodgate, OOO - Own Opinions Only.
http://www.jmwa.demon.co.uk Interested in professional sound
reinforcement and distribution? Then go to http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!


Here is one problem of the concept of feedback itself:
it is all very well to model perceived physical phenomena
in a suitable mathematical form, convenient to 'get rid of'
time by using complex numbers, but

a cause-effect-feedback chain of events does not occur in zero time,
whatever your modeling might lead you to believe.


Ho hummm. The model includes time. Explicity. Its a non issue.

The transfer function of:

Vo(jw) = A(jw)/(1 + A(jw).B(jw))

Includes time via the phase of A(jw) and B(jw))

In the laplace domain

Vo(s) = A(s)/(1 + A(s).B(s))

Incluses time in its inverse.

So here is one, just for Kevin:
what are you actually correcting there with a feedback signal ?


Its all in the wash. The math accounts for any and all time delays. One
just crunches the numbers.


Kevin Aylward

http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

http://www.anasoft.co.uk/replicators/index.html

Understanding, is itself an emotion, i.e. a feeling.
Emotions or feelings can only be "understood" by
consciousness. "Understanding" consciousness can
therefore only be understood by consciousness itself,
therefore the "hard problem" of consciousness, is
intrinsically unsolvable.

Physics is proven incomplete, that is, no
understanding of the parts of a system can
explain all aspects of the whole of such system.


  #58   Report Post  
Ruud Broens
 
Posts: n/a
Default


"Kevin Aylward" wrote in message
...
: Ruud Broens wrote:
: "Kevin Aylward" wrote in
: message ...
:: Please explain to me how you actually *perceive* an emotion *without*
: consciousness? Its a tautology. Its that simple. Consciousness is
: *how* feelings are recognised, i.e. how emotions are recognised.
: Emotions are feelings, i.e. we are consciously aware of them.
:
: Hm, well, this is leading a bit astray, but if you want to discuss
: such matters, let's start with definitions: so what is perception,
: Kevin ?
:
: Most aspects of consciousness gets one into a self referral situation.
: Perception is that which the conscious is aware of. What is
: consciousness, that which can perceive things. Get the drift. I have
: updated my site to address this in more detail.
:
: http://www.anasoft.co.uk/replicators/understanding.html
:
:
: Consciousness is simple a result that occurs when systems get
: sufficiently complicated. However, although it is *only* a function of
: its mass-energy parts, it can not be derived from its parts. It just is.
: It is an example of a Goedel system. True, but not derivable.

Mmm, yesss... this is referred to as the excretionist theory.
But you know all that, being the self-proclaimed expert,
so tell us more about other theories of consciousness,
sure you are aware of them ?
No hard feelings, Kev',
Rudy

: Kevin Aylward
:
:
http://www.anasoft.co.uk
: SuperSpice, a very affordable Mixed-Mode
: Windows Simulator with Schematic Capture,
: Waveform Display, FFT's and Filter Design.
:
: http://www.anasoft.co.uk/replicators/index.html
:
: Understanding, is itself an emotion, i.e. a feeling.
: Emotions or feelings can only be "understood" by
: consciousness. "Understanding" consciousness can
: therefore only be understood by consciousness itself,
: therefore the "hard problem" of consciousness, is
: intrinsically unsolvable.
:
: Physics is proven incomplete, that is, no
: understanding of the parts of a system can
: explain all aspects of the whole of such system.
:
:


  #59   Report Post  
Kevin Aylward
 
Posts: n/a
Default

John Woodgate wrote:
I read in sci.electronics.design that Kevin Aylward
kevindotaylwardEXTR wrote (in
.net) about 'A little
feedback worse than none at all?', on Wed, 19 Nov 2003:
Err.. John and me are arguable, friends. My comment was not at him
personally, but at what he said. What he said was crap.


No, Kevin, it isn't. What happens when you apply lots of feedback
around an amplifier of poor linearity is that you swap maybe 5% of
low-order distortion (2nd, 3rd, 5th.) for 0.05% or so of every
harmonic up to the upper band limit of the amplifier.


What part of "large amounts of feedback" are you having trouble with
John?

The latter
sounds FAR worse,


Why don't you read what I actually wrote.

because of the multiplicity of intermodulation
products, some of which are much larger in amplitude than the
adjacent harmonics.


I have *already* explained, that yes, if the feedback is *low*, than it
can sound much worse. However, if one gets into the *total* THD/IMD
figures of 0.01%, then feedback is great. End of story.

Kevin Aylward

http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

http://www.anasoft.co.uk/replicators/index.html

Understanding, is itself an emotion, i.e. a feeling.
Emotions or feelings can only be "understood" by
consciousness. "Understanding" consciousness can
therefore only be understood by consciousness itself,
therefore the "hard problem" of consciousness, is
intrinsically unsolvable.

Physics is proven incomplete, that is, no
understanding of the parts of a system can
explain all aspects of the whole of such system.


  #60   Report Post  
Ross Matheson
 
Posts: n/a
Default

"Kevin Aylward" wrote:
in ,

[ ... ]

: What the issue here is, is that many may well have missed the obvious.
: Go back and really *think* on what "feelings" "awareness" "emotions"
: "consciousness" really are. They are all self referral. You cannot
: explain any, without invoking the other. For some reason, many have
: missed this fundamental point, and have spent much effort in trying to
: derive consciousness.

"The Tao that can be conceived is not the Tao"
Tao Te Ching

: Understanding, is itself an emotion, i.e. a feeling.
: Emotions or feelings can only be "understood" by
: consciousness. "Understanding" consciousness can
: therefore only be understood by consciousness itself,
: therefore the "hard problem" of consciousness, is
: intrinsically unsolvable.

"As the soft yielding water cleaves obstinate stone,
so to yield with life solves the insoluble"

: Physics is proven incomplete, that is, no
: understanding of the parts of a system can
: explain all aspects of the whole of such system.

No argument there!
But I submit that progress is being made, in understanding time n dimensions!
Cheers!


  #61   Report Post  
Ross Matheson
 
Posts: n/a
Default

"Kevin Aylward" wrote:
in ,

: John Woodgate wrote:
: I read in sci.electronics.design that Kevin Aylward
: kevindotaylwardEXTR wrote (in
: .net) about 'A little
: feedback worse than none at all?', on Wed, 19 Nov 2003:
: Err.. John and me are arguable, friends. My comment was not at him
: personally, but at what he said. What he said was crap.
:
: No, Kevin, it isn't. What happens when you apply lots of feedback
: around an amplifier of poor linearity is that you swap maybe 5% of
: low-order distortion (2nd, 3rd, 5th.) for 0.05% or so of every
: harmonic up to the upper band limit of the amplifier.
:
: What part of "large amounts of feedback" are you having trouble with
: John?
:
: The latter
: sounds FAR worse,
:
: Why don't you read what I actually wrote.
:
: because of the multiplicity of intermodulation
: products, some of which are much larger in amplitude than the
: adjacent harmonics.
:
: I have *already* explained, that yes, if the feedback is *low*, than it
: can sound much worse. However, if one gets into the *total* THD/IMD
: figures of 0.01%, then feedback is great. End of story.
:
: Kevin Aylward

Re "large amounts of feedback" and "great", I wonder what you learned chaps
might think of this, previously bookmarked unable to check tonight site?
http://peufeu.free.fr/audio/memory-1-theory.html [or start from audio/ ]

Up to 100db feedback? I thought it was interesting, and it seemed new &
original ... bookmarked early this year ... in terms of SS device fidelity.

Regards, from a mere amateur & novice;-)

Ross Matheson



  #63   Report Post  
Kevin Aylward
 
Posts: n/a
Default

Ruud Broens wrote:
"Kevin Aylward" wrote in
message ...
Ruud Broens wrote:
"Kevin Aylward" wrote in
message ...
Please explain to me how you actually *perceive* an emotion
*without*
consciousness? Its a tautology. Its that simple. Consciousness is
*how* feelings are recognised, i.e. how emotions are recognised.
Emotions are feelings, i.e. we are consciously aware of them.

Hm, well, this is leading a bit astray, but if you want to discuss
such matters, let's start with definitions: so what is perception,
Kevin ?


Most aspects of consciousness gets one into a self referral
situation. Perception is that which the conscious is aware of. What
is consciousness, that which can perceive things. Get the drift. I
have updated my site to address this in more detail.

http://www.anasoft.co.uk/replicators/understanding.html


Consciousness is simple a result that occurs when systems get
sufficiently complicated. However, although it is *only* a function
of its mass-energy parts, it can not be derived from its parts. It
just is. It is an example of a Goedel system. True, but not
derivable.


Mmm, yesss... this is referred to as the excretionist theory.


Never heard of the word excretionist.

But you know all that, being the self-proclaimed expert,


What I will say here, is that most of what has been written in the past
is wrong. The fundamental reason for this is that they did not know
about computers, or truly understand that the brain is it. They is
nothing else. We are a machine. Sure, the brain operates a bit
different, but the main features are all that is required to get a
reasonable handle on the issues.

so tell us more about other theories of consciousness,
sure you are aware of them ?


Quite frankly, whenever I have trolled the web on this, its all crap.
Every, bit of it.
e.g.http://www.vub.ac.be/CLEA/liane/papers/api/api.html

"This paper proposes that an entity is conscious to the extent it
amplifies information, first by trapping and integrating it through
closure, and second by maintaining dynamics at the edge of chaos through
simultaneous processes of divergence and convergence. The origin of life
through autocatalytic closure, and the origin of an interconnected
worldview through conceptual closure, induced phase transitions in the
degree to which information, and thus consciousness, is locally
amplified. Divergence and convergence of cognitive information may
involve phenomena observed in light e.g. focusing, interference, and
resonance. By making information flow inward-biased, closure shields us
from external consciousness; thus the paucity of consciousness may be an
illusion."


Philosophers, by and large have no idea whatsoever. Consciousness is an
engineering problem.

No hard feelings, Kev',


None at all.


Kevin Aylward

http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

http://www.anasoft.co.uk/replicators/index.html

Understanding, is itself an emotion, i.e. a feeling.
Emotions or feelings can only be "understood" by
consciousness. "Understanding" consciousness can
therefore only be understood by consciousness itself,
therefore the "hard problem" of consciousness, is
intrinsically unsolvable.

Physics is proven incomplete, that is, no
understanding of the parts of a system can
explain all aspects of the whole of such system.


  #64   Report Post  
NewYorkDave
 
Posts: n/a
Default

(Ian Iveson) wrote in message . com...
Your plan seems reasonable to me, and clear in outline. One obvious
question though: if it were possible to take your kind of short-cuts
to console design in the 50s, why didn't they do it?


That's a good question, and I think I have the answer.

The type of circuit I describe DID exist in the '50s in the form of
small self-contained mixers. The type of mixer I'm looking to build
falls roughly into that category, insofar as it's self-contained and
of a fixed configuration.

Larger studio consoles followed a sort of "open system" architecture
where the individual components--amplifiers, equalizers, faders and so
on--were normalized for input/output impedances of 600 ohms and the
console could be reconfigured at will via patchcords. This was handy
when the individual parts of a console were expensive and you couldn't
afford to put, say, an equalizer on every channel. Your console might
have 8 channels but only four equalizers, that could be patched in as
needed. That Langevin wiring diagram link I posted earlier in the
thread shows a typical console arrangement. Note that all
interconnections are brought out to patchbay jacks.


If you take your feedback from the output of the white cathode
follower, you will have a ring of three, which is a classic circuit
for some reason I can't remember.


I would like to do that, but including the cathode follower in the FB
loop means that the master volume control would have to go either
before or after the amplifier/buffer combination, which is undesirable
either from a S/N standpoint (pot BEFORE the amp) or an output
impedance/balance/loading perspective (AFTER the output buffer). I
also wanted to avoid having to use more than two tubes per amplifier.

Of course, if the internal noise of the amplifier were reduced to a
very low level by negative feedback, then the S/N degradation from
putting the pot before the amplifier might not be a problem in
practice. The S/N will get worse as you turn down the pot; but if it's
exceptionally low in the first place, well...
  #66   Report Post  
John Woodgate
 
Posts: n/a
Default

I read in sci.electronics.design that Ross Matheson
wrote (in ) about 'A little
feedback worse than none at all?', on Thu, 20 Nov 2003:

Re "large amounts of feedback" and "great", I wonder what you learned
chaps might think of this, previously bookmarked unable to check
tonight site? http://peufeu.free.fr/audio/memory-1-theory.html [or
start from audio/ ]


The page is not available, but
http://peufeu.free.fr/audio

works. The author seems, in general, to know what he is talking about.
--
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
Interested in professional sound reinforcement and distribution? Then go to
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!
  #67   Report Post  
NewYorkDave
 
Posts: n/a
Default

Patrick Turner wrote in message ...
Your first post on the matter seemed to present a daunting task for us to
design for you


Patrick, I think you misunderstand my intention in the original post.
I'm not asking anyone to design my circuit for me. I just wanted
comments on the distribution of distortion products in tube amplifiers
with negative feedback. This knowledge could help to guide me in
designing my circuit, but I wasn't looking for someone else to do the
design work for me.
  #68   Report Post  
Kevin Aylward
 
Posts: n/a
Default

John Woodgate wrote:
I read in sci.electronics.design that Kevin Aylward
kevindotaylwardEXTR wrote (in
i.net) about 'A little
feedback worse than none at all?', on Wed, 19 Nov 2003:

I have *already* explained, that yes, if the feedback is *low*,


The proliferation of high-order harmonics is also a characteristic of
large amounts of feedback. They don't disappear as you increase the
feedback: each one is reduced but combinations spawn even higher
orders of harmonics and intermodulation products.


What is it with yoiu that you wont read what I wrote.

A *practical* amp *always* generates *all* harmonics. If enough feedback
is used each and every harmonic will stil be less than the open loop for
value of each harmonic.


than it
can sound much worse. However, if one gets into the *total* THD/IMD
figures of 0.01%, then feedback is great. End of story.


IF (and it's a big IF) you really achieved 0.01% IMD, then you'd have
a case.


No its not a big if whatsoever. Its trivial to get 0.005% at 20Khz. Done
it 20 years ago. 20 years later and my mosfet 1000 is still going
strong.
http://www.anasoft.co.uk/studiomaster/Studiomaster.htm


But if you get 0.01% THD by putting lots of feedback around a
not very linear amplifier, then you will NOT get 0.01% IMD.


If you use enough feed back you will, but I am not discussing poorly
designed amps.

Secondly, if it were so bad, tube amps would sound dreadful as they
typically have low feedback, like say 15db.


We added a weighted harmonic distortion option to IEC 60268-3
precisely because IC manufacturers were offering audio chips with
this problem; poor open-loop linearity but lots of feedback. Good THD
figures but very poor IMD. The chip manufacturers refused to accept
that IMD was of any significance (well they would, wouldn't they) so
we 'gave' them weighted THD instead.


I'm not really discussing cheap and nasty ic chips. I am referring to
competently designed discrete hi-fi amps. Of course ic amps are usually
poor.

Kevin Aylward

http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

http://www.anasoft.co.uk/replicators/index.html

Understanding, is itself an emotion, i.e. a feeling.
Emotions or feelings can only be "understood" by
consciousness. "Understanding" consciousness can
therefore only be understood by consciousness itself,
therefore the "hard problem" of consciousness, is
intrinsically unsolvable.

Physics is proven incomplete, that is, no
understanding of the parts of a system can
explain all aspects of the whole of such system.


  #69   Report Post  
John Woodgate
 
Posts: n/a
Default

I read in sci.electronics.design that Kevin Aylward kevindotaylwardEXTR
wrote (in
i.net) about 'A little feedback worse than none at all?', on Wed, 19
Nov 2003:
What is it with yoiu that you wont read what I wrote.


I am reading it, Kevin. I just don't accept what you say.

A *practical* amp *always* generates *all* harmonics. If enough feedback
is used each and every harmonic will stil be less than the open loop for
value of each harmonic.


No. An amplifier with very little 9th harmonic, for example, but quite a
bit of 3rd and fifth, is quite likely to have MORE 9th when feedback is
applied. It could also have less, because the new 9th might be in the
opposite polarity to the original.


than it
can sound much worse. However, if one gets into the *total* THD/IMD
figures of 0.01%, then feedback is great. End of story.


IF (and it's a big IF) you really achieved 0.01% IMD, then you'd have
a case.


No its not a big if whatsoever. Its trivial to get 0.005% at 20Khz.


How do you get 0.005% **IMD** at a single frequency?

It's trivial to get 0.005% **THD** at 20 kHz if the closed-loop
bandwidth is low enough.(;-)

Done
it 20 years ago. 20 years later and my mosfet 1000 is still going
strong.
http://www.anasoft.co.uk/studiomaster/Studiomaster.htm

I expect your amp has good open-loop linearity. In that case, you won't
have the problem I'm talking about.


But if you get 0.01% THD by putting lots of feedback around a
not very linear amplifier, then you will NOT get 0.01% IMD.


If you use enough feed back you will, but I am not discussing poorly
designed amps.


But that's the whole POINT!!! It IS bad design to put lots of feedback
around an amplifier with poor open-loop linearity.

Secondly, if it were so bad, tube amps would sound dreadful as they
typically have low feedback, like say 15db.


I feel like giving up! LOW feedback isn't a serious source of highly
extended harmonic spectra, which lead to bad IM performance.


We added a weighted harmonic distortion option to IEC 60268-3
precisely because IC manufacturers were offering audio chips with
this problem; poor open-loop linearity but lots of feedback. Good THD
figures but very poor IMD. The chip manufacturers refused to accept
that IMD was of any significance (well they would, wouldn't they) so
we 'gave' them weighted THD instead.


I'm not really discussing cheap and nasty ic chips. I am referring to
competently designed discrete hi-fi amps. Of course ic amps are usually
poor.


Yes, you are arguing from different initial assumptions. That's why you
don't accept what I am saying.
--
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
Interested in professional sound reinforcement and distribution? Then go to
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!
  #70   Report Post  
Ruud Broens
 
Posts: n/a
Default


"Kevin Aylward" wrote in message
...
: Ruud Broens wrote:
: "Kevin Aylward" wrote in
: message ...
: Ruud Broens wrote:
: "Kevin Aylward" wrote in
: message ...
: Please explain to me how you actually *perceive* an emotion
: *without*
: consciousness? Its a tautology. Its that simple. Consciousness is
: *how* feelings are recognised, i.e. how emotions are recognised.
: Emotions are feelings, i.e. we are consciously aware of them.
:
: Hm, well, this is leading a bit astray, but if you want to discuss
: such matters, let's start with definitions: so what is perception,
: Kevin ?
:
: Most aspects of consciousness gets one into a self referral
: situation. Perception is that which the conscious is aware of. What
: is consciousness, that which can perceive things. Get the drift. I
: have updated my site to address this in more detail.
:
: http://www.anasoft.co.uk/replicators/understanding.html
:
:
: Consciousness is simple a result that occurs when systems get
: sufficiently complicated. However, although it is *only* a function
: of its mass-energy parts, it can not be derived from its parts. It
: just is. It is an example of a Goedel system. True, but not
: derivable.
:
: Mmm, yesss... this is referred to as the excretionist theory.
:
: Never heard of the word excretionist.

Actually, it's called excretionism, just playing there with letters
& words - call it a little eccentricity - to denote a person holding
such a belief.

:
: But you know all that, being the self-proclaimed expert,
:
: What I will say here, is that most of what has been written in the past
: is wrong. The fundamental reason for this is that they did not know
: about computers, or truly understand that the brain is it. They is
: nothing else. We are a machine. Sure, the brain operates a bit
: different, but the main features are all that is required to get a
: reasonable handle on the issues.
:
: so tell us more about other theories of consciousness,
: sure you are aware of them ?
:
: Quite frankly, whenever I have trolled the web on this, its all crap.
: Every, bit of it.
: e.g.http://www.vub.ac.be/CLEA/liane/papers/api/api.html
:
: "This paper proposes that an entity is conscious to the extent it
: amplifies information, first by trapping and integrating it through
: closure, and second by maintaining dynamics at the edge of chaos through
: simultaneous processes of divergence and convergence. The origin of life
: through autocatalytic closure, and the origin of an interconnected
: worldview through conceptual closure, induced phase transitions in the
: degree to which information, and thus consciousness, is locally
: amplified. Divergence and convergence of cognitive information may
: involve phenomena observed in light e.g. focusing, interference, and
: resonance. By making information flow inward-biased, closure shields us
: from external consciousness; thus the paucity of consciousness may be an
: illusion."
:
:
: Philosophers, by and large have no idea whatsoever. Consciousness is an
: engineering problem.
:
: No hard feelings, Kev',
:
: None at all.

Some, knowledgeble in the fields of cognitive psychology, AI, etc. might
have chuckled there, as it's a key debating issue : hard vs. soft
interpretation
of observations in the matter. Interesting as the subject can be, I think
it's better
to give it a rest, most ppl. will consider this way OT anyway.
Great though the web can be for all sorts of matters, I don't think some
cut & paste actions constitutes the base from which you gather an
in-depth knowledge & understanding of subjects such as these.
FYI, the computer metaphor *has* been used for many a year now,
before that it was the telephone exchange..

Now, where philosophy, valid reasoning, belief systems, what constututes
knowledge, etc. come in is : if the metaphor (model) describes & predicts
behaviour perfectly, is this actually 'what's going on' in the world ?
The hard AI party line says: quack like a duck, walk like a duck, duck
dropping's
all' round -- must be a duck
While the 'softies' say: for all practical usage, the model is great...but
ad-lib
applying Occam's razor - not some proven law, mind you, 'just' a rule of
thumb,
common sense - is simply not valid.

This has all a lot to do with the basic philosophic distinction of
Realist vs. Idealist a matter of epistomology

Where as for a realist, walking into a brick wall, bleeding nose and all,
certainly is proof of this brick wall 'being out there'

Not so for an Idealist, who maintains, there is no way to
verify this, it is only 'the sensation' of brick wall, bleeding nose
etc. that one can talk about

Just a final bit of spice then: physicists do *not* hold a realist's
view of reality, that is, a physicist will tell you physics deals with
correlations of perceived sensory data, a phenomenological approach.
And, sorry to say, common sense just gets you so far.

May I suggest, if the subject interests you, to get a copy of
Foundations of Cognitive Science, ed. Michael I. Posner - MIT Press 1986
or a somewhat more compact
The Mind's New Science - Howard Gardner - Basic Books1985
:
:
: Kevin Aylward
:
:
http://www.anasoft.co.uk
: SuperSpice, a very affordable Mixed-Mode
: Windows Simulator with Schematic Capture,
: Waveform Display, FFT's and Filter Design.
:
: http://www.anasoft.co.uk/replicators/index.html
:
: Understanding, is itself an emotion, i.e. a feeling.
: Emotions or feelings can only be "understood" by
: consciousness. "Understanding" consciousness can
: therefore only be understood by consciousness itself,
: therefore the "hard problem" of consciousness, is
: intrinsically unsolvable.
:
: Physics is proven incomplete, that is, no
: understanding of the parts of a system can
: explain all aspects of the whole of such system.
:
Here's a little piece by Gilbert Ryle - 1949:
"I'm not interested in the issues of how one sees or
understands something if those seeings or
understandings involve the positing of some
internal understanding or perceptual mechanisms"


Happy readin',
Rudy




  #72   Report Post  
Kevin Aylward
 
Posts: n/a
Default

Ruud Broens wrote:
"Kevin Aylward" wrote in
message ...




Philosophers, by and large have no idea whatsoever. Consciousness is
an engineering problem.

No hard feelings, Kev',


None at all.


Some, knowledgeble in the fields of cognitive psychology, AI, etc.
might have chuckled there, as it's a key debating issue : hard vs.
soft interpretation
of observations in the matter. Interesting as the subject can be, I
think it's better
to give it a rest, most ppl. will consider this way OT anyway.
Great though the web can be for all sorts of matters, I don't think
some cut & paste actions constitutes the base from which you gather an
in-depth knowledge & understanding of subjects such as these.


I disagree on this last bit. If you do a bit of trolling and read a few
snippets of the pros papers on there university sites, you can get a
reasonable feel as to what the overall views are. This one snippet is
indeed typical of them all. I did spend a bit of time on this, just to
see what the alternatives were.

FYI, the computer metaphor *has* been used for many a year now,
before that it was the telephone exchange..


The details don't matter. Its input, processing and output. The brain
has storage and there are sensors here and there, and it gets
replicated. Thats all that is required to get a good picture of what's
going on.


Now, where philosophy, valid reasoning, belief systems, what
constututes knowledge, etc. come in is : if the metaphor (model)
describes & predicts behaviour perfectly, is this actually 'what's
going on' in the world ? The hard AI party line says: quack like a
duck, walk like a duck, duck dropping's
all' round -- must be a duck


There can be many models to describe the same reality. For example,
special relativity and the lorentz ether theory have identical
equations. Mathematically they are indistinguishable. However, one has
absolute space, one doesn't.

While the 'softies' say: for all practical usage, the model is
great...but ad-lib
applying Occam's razor - not some proven law, mind you, 'just' a rule
of thumb,
common sense - is simply not valid.

This has all a lot to do with the basic philosophic distinction of
Realist vs. Idealist a matter of epistomology

Where as for a realist, walking into a brick wall, bleeding nose and
all, certainly is proof of this brick wall 'being out there'

Not so for an Idealist, who maintains, there is no way to
verify this, it is only 'the sensation' of brick wall, bleeding nose
etc. that one can talk about


This is about absolute proof and proof beyond reasonable doubt. We know
absolute proof is impossible in general, however, society executes
people on much less than absolute proof.


Just a final bit of spice then: physicists do *not* hold a realist's
view of reality, that is, a physicist will tell you physics deals with
correlations of perceived sensory data, a phenomenological approach.


This is not really true of all or even most physicists. Many hold the
view that there is an objective reality, that may be describable by many
different models. Some hold the view that there is no objective reality.
I am in the same camp as Einstein, that there is an objective reality.
Because I know Goedal, I can accept that this may be true, even without
proof. The evidence suggests that there is a real reality, despite some
claims to the contrary my writers of popular physics Bantam paperbacks.

A main issue with popular expressed physics is that many metaphysical
ideas are presented as being a consequence of the physics known to work,
when in fact, the physics don't care about someone's particular
interpretation. For example, collapse of the wave function, particles in
two places at once, or many universes, are all waffle ideas that are not
required in the slightest in quantum Mechanics. They are redundant
add-ons. QM works pefectly well without these daft ideas.

Kevin Aylward

http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.


  #73   Report Post  
Kevin Aylward
 
Posts: n/a
Default

John Woodgate wrote:
I read in sci.electronics.design that Kevin Aylward
kevindotaylwardEXTR wrote (in
i.net) about 'A little
feedback worse than none at all?', on Wed, 19 Nov 2003:
What is it with yoiu that you wont read what I wrote.


I am reading it, Kevin. I just don't accept what you say.


Your simple not listening.


A *practical* amp *always* generates *all* harmonics. If enough
feedback is used each and every harmonic will stil be less than the
open loop for value of each harmonic.


No. An amplifier with very little 9th harmonic, for example, but
quite a bit of 3rd and fifth, is quite likely to have MORE 9th when
feedback is applied.


NOT IF THE FEEDBACK IS LARGE ENOUGTH.

Why can't you understand this.

It could also have less, because the new 9th
might be in the opposite polarity to the original.


than it
can sound much worse. However, if one gets into the *total* THD/IMD
figures of 0.01%, then feedback is great. End of story.

IF (and it's a big IF) you really achieved 0.01% IMD, then you'd
have a case.


No its not a big if whatsoever. Its trivial to get 0.005% at 20Khz.


How do you get 0.005% **IMD** at a single frequency?


Dont be an arse. There is an assumption here, lets say the other one is
at 19Khz


It's trivial to get 0.005% **THD** at 20 kHz if the closed-loop
bandwidth is low enough.(;-)


Look, there are even amps that have *widband* THD/IMD at 0.001%.


Done
it 20 years ago. 20 years later and my mosfet 1000 is still going
strong.
http://www.anasoft.co.uk/studiomaster/Studiomaster.htm

I expect your amp has good open-loop linearity. In that case, you
won't have the problem I'm talking about.


It has to be a pretty pathetic amp design to have poor open loop
linearity. Sure, there were some dreadful amps in the past, but as I
explained in my published letters in Electronics World, its simple not
an issue to design an amplifier correctly.



But if you get 0.01% THD by putting lots of feedback around a
not very linear amplifier, then you will NOT get 0.01% IMD.


If you use enough feed back you will, but I am not discussing poorly
designed amps.


But that's the whole POINT!!! It IS bad design to put lots of feedback
around an amplifier with poor open-loop linearity.


What's your definition of poor open loop linearity?


Secondly, if it were so bad, tube amps would sound dreadful as they
typically have low feedback, like say 15db.


I feel like giving up! LOW feedback isn't a serious source of highly
extended harmonic spectra, which lead to bad IM performance.


Of course it is. Your now contradicting yourself. With low feedback, a
square law mixes with its input to generate many odd harmonics. With
large enough feedback, it clobbers these newly introduced harmonies.



We added a weighted harmonic distortion option to IEC 60268-3
precisely because IC manufacturers were offering audio chips with
this problem; poor open-loop linearity but lots of feedback. Good
THD figures but very poor IMD. The chip manufacturers refused to
accept that IMD was of any significance (well they would, wouldn't
they) so we 'gave' them weighted THD instead.


I'm not really discussing cheap and nasty ic chips. I am referring to
competently designed discrete hi-fi amps. Of course ic amps are
usually poor.


Yes, you are arguing from different initial assumptions. That's why
you don't accept what I am saying.


I stated what my assumption was, right from the start. Large amounts of
feedback.

Kevin Aylward

http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

http://www.anasoft.co.uk/replicators/index.html

Understanding, is itself an emotion, i.e. a feeling.
Emotions or feelings can only be "understood" by
consciousness. "Understanding" consciousness can
therefore only be understood by consciousness itself,
therefore the "hard problem" of consciousness, is
intrinsically unsolvable.

Physics is proven incomplete, that is, no
understanding of the parts of a system can
explain all aspects of the whole of such system.


  #74   Report Post  
Patrick Turner
 
Posts: n/a
Default



Kevin Aylward wrote:


I have *already* explained, that yes, if the feedback is *low*, than it
can sound much worse. However, if one gets into the *total* THD/IMD
figures of 0.01%, then feedback is great. End of story.


And this has been demonstrated in measurements described in two articles in
the
last 20 years which appeared in Wireless World, and Electronics World.
But the articles also concluded that the "sound worse result"
happened where thd to begin with was high, say over 5%,
and also FB was low, say under 12 dB.
Where thd was initially low, and simple 2H, say below 1%, then 10 dB of FB
will reduce the 2H by around 1/3, and only slightly introduce some 3H as a
result
of imd action, but its at a low level.

What has to be kept in mind about thd/imd with regard to triode signal
amps, is that it
starts off at zero at zero vo, then rises to the maximums we are talking
about, say 1%,
at about 10vrms output from a typical SET signal amp, and then rises to
say 5% at 60 vo.

But usually, its rare in preamps to have more than 1vo, so thd is under
0.1% to start with, and if the triodes are selected right, say 6SN7/6CG7,
and loaded with CCS loads, their thd is considerably reduced further to
negligible levels,
and the thd does not tend to increase linearly with vo, but
is slow to increase at first, and only increase more rapidly as vo rises
above where
we want to use the tube.

I have a preamp with bootstrapped follower stages, ( like mu follower
stages ),
and there is a phono amp, passive RIAA eq, tone control stage, when I wanna
use it,
and a gain stage, also deletable, and a cathode follower buffer.
FB is only used with the Baxandal network tone control stage,
and inherent with the CF output buffer.
With 10v output from any stage, thd is less than 0.2%, and at 1vo, thd is
around the 0.02%
mark, depending whether the 2H is allowed to cancel the next stage's 2H,
which happens when the line gain stage is used with say the phono stage.

Noise is worst in the phono amp, but snr is around -75 dB.
The noise of the phono amp is reduced from what you'd get
from an all tube line up by the use of a fet, the 2SK369, as an input
device, in a cascode arrangement with a following triode.
The snr is a lot better for line inputs, because the signal level input is
high compared
to a phono amp's, and yet the input noise of a triode is typically 2 uV.

The use of discrete j-fets on their own in either SE or balanced stages
isn't a pretty picture
once the signal level climbs above 0.1v, because the fet thd is far worse
than a triode's,
like about 20 dB worse. But where only mV are being processed,
the fet does OK.
Bjts are just as bad as the fets, and offer odd order thd as well.
So to linearise any SS devices, FB is required, but not in triode amps,
if you don't want to, and you design for it.
If FB is added to triode signal amps, the thd becomes very
low without much FB applied, because it was low to begin with.

Balanced circuits using triodes reduce their thd by around 20 dB
without using any FB.

Before anyone condemns triodes on the basis they have high N&D,
they should just check the facts.

Patrick Turner.

  #75   Report Post  
Ruud Broens
 
Posts: n/a
Default


"Kevin Aylward" wrote in message
...
: Ruud Broens wrote:
: "Kevin Aylward" wrote in
: message ...
:
:
::
: Just a final bit of spice then: physicists do *not* hold a realist's
: view of reality, that is, a physicist will tell you physics deals with
: correlations of perceived sensory data, a phenomenological approach.
:
: This is not really true of all or even most physicists. Many hold the
: view that there is an objective reality, that may be describable by many
: different models. Some hold the view that there is no objective reality.
: I am in the same camp as Einstein, that there is an objective reality.
: Because I know Goedal, I can accept that this may be true, even without
: proof. The evidence suggests that there is a real reality, despite some
: claims to the contrary my writers of popular physics Bantam paperbacks.
:
: A main issue with popular expressed physics is that many metaphysical
: ideas are presented as being a consequence of the physics known to work,
: when in fact, the physics don't care about someone's particular
: interpretation. For example, collapse of the wave function, particles in
: two places at once, or many universes, are all waffle ideas that are not
: required in the slightest in quantum Mechanics. They are redundant
: add-ons. QM works pefectly well without these daft ideas.

Funny that you should mention Quantum Physics - it's precisely the
findings in this field that tell us, Idealism is the 'best fit'.
Maybe add some Feymann books to the list there..
Rudy
:
: Kevin Aylward
:
:
http://www.anasoft.co.uk
: SuperSpice, a very affordable Mixed-Mode
: Windows Simulator with Schematic Capture,
: Waveform Display, FFT's and Filter Design.
:
:




  #76   Report Post  
Patrick Turner
 
Posts: n/a
Default



NewYorkDave wrote:

Patrick Turner wrote in message ...
Your first post on the matter seemed to present a daunting task for us to
design for you


Patrick, I think you misunderstand my intention in the original post.
I'm not asking anyone to design my circuit for me. I just wanted
comments on the distribution of distortion products in tube amplifiers
with negative feedback. This knowledge could help to guide me in
designing my circuit, but I wasn't looking for someone else to do the
design work for me.


OK, well you sure got a lot of replies about distortion.

But to know about the thd in any given application, we'd
need a schematic of what's proposed.

You design your circuit, and maybe post the address where we can see
the amplifier stage schmatics if you wish,
and I am sure you'll get another lot of comments regarding
how to do it better, worse, or why at all, and why not opamps!

One has to learn to ignore a fair bit of what is said around here,
its a noisy pub sometimes.

Patrick Turner.


  #77   Report Post  
Ruud Broens
 
Posts: n/a
Default


"NewYorkDave" wrote in message
om...
: Patrick Turner wrote in message
...
: Your first post on the matter seemed to present a daunting task for us
to
: design for you
:
: Patrick, I think you misunderstand my intention in the original post.
: I'm not asking anyone to design my circuit for me. I just wanted
: comments on the distribution of distortion products in tube amplifiers
: with negative feedback. This knowledge could help to guide me in
: designing my circuit, but I wasn't looking for someone else to do the
: design work for me.

Hi, Dave, excuse the lenghty side-thread there,
but wouldn't it be great, having your modular mixing desk,
part by part,
commented and suggested on - in a constructive, helpfull way -

not sure if leavin' SED in is a good idea, but he, nothing wrong
with a little cross-posting now-and-then. A web-sociology
neo-behaviorist might right now be typing something like
"it's good to have some mental cross-breeding, to keep the
web population healthy"

For instance, if i were in your position, i'd "worry" about
noise, dynamic range, first, then see what you can compromize
on in matters of distortion.
BTW found a place with 'very' cheap EF86's & C3m's
Can e-mail you the link be4 here..
Cheers,
Rudy


  #78   Report Post  
John Popelish
 
Posts: n/a
Default

NewYorkDave wrote:

Patrick Turner wrote in message ...
Your first post on the matter seemed to present a daunting task for us to
design for you


Patrick, I think you misunderstand my intention in the original post.
I'm not asking anyone to design my circuit for me. I just wanted
comments on the distribution of distortion products in tube amplifiers
with negative feedback. This knowledge could help to guide me in
designing my circuit, but I wasn't looking for someone else to do the
design work for me.


I think the important fact to keep in mind is that negative feedback
does not have much chance of increasing the high harmonics when it is
used to suppress the low harmonics, It just allows them to be more
audible, because the low (and more pleasant sounding) harmonics get
reduced more than the higher (less pleasant) ones do. This is a
result of there being more excess gain and less phase shift at the
lower harmonic frequencies.

So, first, you try to design an amplifier that has lowest amount of
the higher harmonics before the loop is closed. The feedback will
then take care of the lower harmonics, as long as you stay well away
from saturation, where the open loop gain falls to the point that the
negative feedback drops out right when the harmonic content jumps up.
Headroom is probably more important than harmonic purity.

None of this is scientific, but just rule of thumb stuff.

--
John Popelish
  #79   Report Post  
John Popelish
 
Posts: n/a
Default

NewYorkDave wrote:

Patrick Turner wrote in message ...
Your first post on the matter seemed to present a daunting task for us to
design for you


Patrick, I think you misunderstand my intention in the original post.
I'm not asking anyone to design my circuit for me. I just wanted
comments on the distribution of distortion products in tube amplifiers
with negative feedback. This knowledge could help to guide me in
designing my circuit, but I wasn't looking for someone else to do the
design work for me.


I think the important fact to keep in mind is that negative feedback
does not have much chance of increasing the high harmonics when it is
used to suppress the low harmonics, It just allows them to be more
audible, because the low (and more pleasant sounding) harmonics get
reduced more than the higher (less pleasant) ones do. This is a
result of there being more excess gain and less phase shift at the
lower harmonic frequencies.

So, first, you try to design an amplifier that has lowest amount of
the higher harmonics before the loop is closed. The feedback will
then take care of the lower harmonics, as long as you stay well away
from saturation, where the open loop gain falls to the point that the
negative feedback drops out right when the harmonic content jumps up.
Headroom is probably more important than harmonic purity.

None of this is scientific, but just rule of thumb stuff.

--
John Popelish
  #80   Report Post  
Patrick Turner
 
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John Popelish wrote:

NewYorkDave wrote:

Patrick Turner wrote in message ...
Your first post on the matter seemed to present a daunting task for us to
design for you


Patrick, I think you misunderstand my intention in the original post.
I'm not asking anyone to design my circuit for me. I just wanted
comments on the distribution of distortion products in tube amplifiers
with negative feedback. This knowledge could help to guide me in
designing my circuit, but I wasn't looking for someone else to do the
design work for me.


I think the important fact to keep in mind is that negative feedback
does not have much chance of increasing the high harmonics when it is
used to suppress the low harmonics, It just allows them to be more
audible, because the low (and more pleasant sounding) harmonics get
reduced more than the higher (less pleasant) ones do. This is a
result of there being more excess gain and less phase shift at the
lower harmonic frequencies.


My experience reveals that when the open loop bandwidth
of the amp is low at the top half of the AF band, ie, above
1 kHz the response rolls off, with increasing phase lag, and the thd is high, and the FB is a mild amount,
then although the FB reduces the LF harmonics, the HF harmonics
are not reduced, and hF harmonics of fundementals below 1 kHz
can be increased.
The outcome in such a case of FB application results in a more complex
mish mash of harmonics than when one started, and weighting them
makes things worse from the ear's point of view.
The FB doesn't do much to improve the open loop character.

Transistor amps typically have an open loop response curve
that looks like an arch, with a peak at 500 Hz, and rolling off
at 6 dB/octave either side. thd might be 5% at full po at 500 Hz.
And this is even with an emitter follower output, itself an amount of FB
= maybe 30 dB.
The main thd and noise to be reduced is in the driver stage,
which may have an open loop gain of 10,000.
This is reduced by 54 dB of global NFB to a gain of only 20.
The 5% of thd is reduced around 50 dB,
to 0.0166 %.
But at 30 Hz, or 10 kHz, where open loop gain is less,
the thd reduction is much less, but then we cannot hear the harmonics of 10 kHz and above.


So, first, you try to design an amplifier that has lowest amount of
the higher harmonics before the loop is closed.


That's easy with triodes.

The feedback will
then take care of the lower harmonics, as long as you stay well away
from saturation, where the open loop gain falls to the point that the
negative feedback drops out right when the harmonic content jumps up.
Headroom is probably more important than harmonic purity.


There is no reason why the FB in tube amps cannot
be arranged to reduce the harmonics as much as it does at 500 Hz
as at 10 kHz, because its easy to make a tube amp with 10 kHz of open loop
bandwidth.

With SS amps, and because so much FB is used, you can afford to have less gain
at 10 Khz, because even though there may be 54 dB of FB at 500 Hz,
there will still be maybe 20 dB at 10 kHz.

And not all tube amps are angelic when it comes to OPT quality,
and the phase shift and roll off caused by leakage ans stray C
is such that the HF gain MUST be rolled off, and phase shift
reduced by zobel networks, to step the gain, so
FB can be applied, and yet keep the amp stable even with a capacitor load.

Such amps can sound fine, but I think the best sounding start with wide open loop
BW, and use wide BW OPTs.

Cascaded signal stages may also need gain reducing networks for stabilty
reasons.



None of this is scientific, but just rule of thumb stuff.


I think it IS very scientific stuff, but there are rules of thumb about tube amps,
and if adhered to, the measured result is quite fine.

Patrick Turner.



--
John Popelish


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