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  #121   Report Post  
Robert Morein
 
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Default Audio amplifier design trivial?


"S888Wheel" wrote in message
...
Dave said


But not in the same way. The "sound quality" that studio guys are
concered with is often times at odds with the "best reproduction" of
music. This is because they have more pressing issues, i.e. - how is
this going to sound on radio, in the clubs, in the car, etc. And
sometimes it's about keeping the artist happy.








All too often the real underlying preasure is how to get something in the

can
by the end of the day.


Yes, and many complain they are deliberately required to ruin recordings in
the requirement to make the recording sound the loudest.

All good reason to use the most accurate monitors available .


  #122   Report Post  
S888Wheel
 
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Default Audio amplifier design trivial?


Yes, and many complain they are deliberately required to ruin recordings in
the requirement to make the recording sound the loudest.


This is probably the biggest problem in commercial recordings for the past 10
years. The same problem seems to plague the vast majority of reissues as
well.Although it has always been an isue, I think now more so than ever, much
of audiophilia involves the persuit of the best sounding commercial releases of
the music.
  #123   Report Post  
trotsky
 
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Arny Krueger wrote:
"trotsky" wrote in message




Audiophiles are
extremely critical of the equipment, and studio guys are extremely
critical of the sound on a recording.



One would hope that audiophiles are extremely critical of sound quality, and
that studio guys are also extremely critical of sound quality.



One would hope wrong, then.


For them the equipment is a
means to an end, and hence they don't give it the same scrutiny that
audiophiles do.



One differences is that engineers have a lot more at stake when they
audition recordings.



Sure they do, Arny. There are objective ways of measuring their skills,
right?

  #124   Report Post  
Nousaine
 
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Default Audio amplifier design trivial?

"Robert Morein"
wrote:


"Arny Krueger" wrote in message
...

"Nousaine" wrote in message
...
"Robert Morein"
wrote:

nousaine wrote:

Actually the best-performing speaker I've tested DO come with their

own
amplifiers and application specific EQ.

I wonder what Mr Atkinson's experience may be in this regard.

What speaker do you refer to?

I meant to use the plural "best-performing speakerS"


Just guessing here, but I suspect that Nousaine is referring to speakers
like the Paradigm Monitors that have built-in power amps and certain

powered
subwoofers. Self-powered subwoofers are very common.

Self-powered speakers are very common in audio production studios. If
someone told me that more than half of all current sales in this product
category were self-powered, I wouldn't be surprised. This is a market
composed of very critical listeners that have unparalleled experience with
live music.


The divergence of requirement of studio monitors vs. audiophile applications
is well known.
While self powered speakers are optimal from the engineering point of view,
they do not allow the user to optimize the sound to his liking by
appropriate combination of speaker and amplifier.

Audiophiles have justifiable desire to modify the tonality of the system to
their liking, while audio engineers have an obligation to a much larger
audience to produce mixes which are acceptable to a much larger group.


Actually people don't modify tonality of loudspeakers by using nominally
competent amplifiers. However the CAN improve tonality by using
application-equalization specific amplifiers in powered speaker systems.
  #125   Report Post  
Robert Morein
 
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Default Audio amplifier design trivial?


"Nousaine" wrote in message
...
"Robert Morein"
wrote:


"Arny Krueger" wrote in message
...

"Nousaine" wrote in message
...
"Robert Morein"
wrote:

nousaine wrote:

Actually the best-performing speaker I've tested DO come with

their
own
amplifiers and application specific EQ.

I wonder what Mr Atkinson's experience may be in this regard.

What speaker do you refer to?

I meant to use the plural "best-performing speakerS"

Just guessing here, but I suspect that Nousaine is referring to

speakers
like the Paradigm Monitors that have built-in power amps and certain

powered
subwoofers. Self-powered subwoofers are very common.

Self-powered speakers are very common in audio production studios. If
someone told me that more than half of all current sales in this

product
category were self-powered, I wouldn't be surprised. This is a market
composed of very critical listeners that have unparalleled experience

with
live music.


The divergence of requirement of studio monitors vs. audiophile

applications
is well known.
While self powered speakers are optimal from the engineering point of

view,
they do not allow the user to optimize the sound to his liking by
appropriate combination of speaker and amplifier.

Audiophiles have justifiable desire to modify the tonality of the system

to
their liking, while audio engineers have an obligation to a much larger
audience to produce mixes which are acceptable to a much larger group.


Actually people don't modify tonality of loudspeakers by using nominally
competent amplifiers. However the CAN improve tonality by using
application-equalization specific amplifiers in powered speaker systems.


I'm a singular instance of "actually people".
I have a large stable of amplifiers which I use to modify the sound of my
speakers.
Currently, I'm running the following in my main listening room:
Acoustat TNT-200 with KEF Reference III,
Bridged Hafler XL-280's to run NEAR 50ME and Polk LS15.
I found the KEF Reference III's to be too dull with the Haflers, and
switched them over to the Acoustat.
The Acoustat had been powering Acoustat 2+2's in my office, but the sound
was not pleasing. I tried XL280's, but ultimately chose a Parasound
HCA2200ii.
The Polk LS15s are a new acquisition, and they, too, seem a little flat, so
I'll try hooking them up to the TNT-200.
The NEAR 50ME's were at one time powered by the TNT-200, but there was too
much sizzle; hence the switch to the TNT-200.

All of these choices are reversible; I have extras of each amplifier, nor am
I motivated to sell any, so my choices are not motivated by economic
concerns or convenience. I make whatever connections I want, depending upon
what I believe I hear.








  #126   Report Post  
George M. Middius
 
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Default Audio amplifier design trivial?



Robert Morein said:

I have a large stable of amplifiers which I use to modify the sound of my speakers.


Are you sure you don't use them to modify your expectations?

Acoustat TNT-200 with KEF Reference III,
Bridged Hafler XL-280's to run NEAR 50ME and Polk LS15.
Parasound HCA2200ii


Do you have a permit to own three (or is it six?) overpriced and fully
functional amplifiers?

I have extras of each amplifier


Clearly you don't know the value of money. Nousiane could buy four
Brystons with 200-year warranties with the money you spent on your 22
cheesy amplifiers.



  #127   Report Post  
Arny Krueger
 
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Default Audio amplifier design trivial?

"Robert Morein" wrote in message


I'm a singular instance of "actually people".


Robert Morein certifies himself as having far better ears than any other
living human. That's why he does not need to educate himself by visiting
www.pcabx.com. He already knows in his mind that he can get a perfect score
on every listening test there. Why waste time actually listening?

I have a large stable of amplifiers which I use to modify the sound
of my speakers.


It's an interesting ritual. The person afflicted with amplifier speaker
adjustment dementia hooks up various amplifiers to his speakers and
perceives that he has improved the sound quality.

He hooks up amplifier "B", he perceives that the sound quality improves over
that of amplifier "A"

He hooks up amplifier "C", he perceives that the sound quality improves over
that of amplifier "B".

He hooks up amplifier "D", he perceives that the sound quality improves over
that of amplifier "C".

He hooks up amplifier "A", he perceives that the sound quality improves over
that of amplifier "D".

He hooks up amplifier "B", he perceives that the sound quality improves over
that of amplifier "A"

He hooks up amplifier "C", he perceives that the sound quality improves over
that of amplifier "B".

He hooks up amplifier "D", he perceives that the sound quality improves over
that of amplifier "C".

He hooks up amplifier "A", he perceives that the sound quality improves over
that of amplifier "D".

He hooks up amplifier "B", he perceives that the sound quality improves over
that of amplifier "A"

He hooks up amplifier "C", he perceives that the sound quality improves over
that of amplifier "B".

He hooks up amplifier "D", he perceives that the sound quality improves over
that of amplifier "C".

He hooks up amplifier "A", he perceives that the sound quality improves over
that of amplifier "D".

Now quite amazingly, the sound quality is 12 times better than it was to
start with!

Pretty amazing, eh?

Makes guys like Nousaine and I, who try to adjust our equalizers to get
better sound quality look pretty foolish, eh?

Makes all those recording engineers, who try to adjust their equalizers to
get better sound quality look pretty foolish, as well!

Currently, I'm running the following in my main listening room:
Acoustat TNT-200 with KEF Reference III,
Bridged Hafler XL-280's to run NEAR 50ME and Polk LS15.
I found the KEF Reference III's to be too dull with the Haflers, and
switched them over to the Acoustat.
The Acoustat had been powering Acoustat 2+2's in my office, but the
sound was not pleasing. I tried XL280's, but ultimately chose a
Parasound HCA2200ii.
The Polk LS15s are a new acquisition, and they, too, seem a little
flat, so I'll try hooking them up to the TNT-200.
The NEAR 50ME's were at one time powered by the TNT-200, but there
was too much sizzle; hence the switch to the TNT-200.


Just replace Acoustat TNT-200 with Amplifier "A" and so on.

All of these choices are reversible; I have extras of each amplifier,
nor am I motivated to sell any, so my choices are not motivated by
economic concerns or convenience. I make whatever connections I want,
depending upon what I believe I hear.


This is the moral equivalent of one of those TV evangelist healing services,
except that through the miracles of science, Bob has dispensed with the TV
evangelist and the TV.

I've VERY impressed. Good Job, Bob!


  #128   Report Post  
Sockpuppet Yustabe
 
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"Arny Krueger" wrote in message
...

Makes guys like Nousaine and I, who try to adjust our equalizers to get
better sound quality look pretty foolish, eh?


Clueless, as usual.




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  #129   Report Post  
Robert Morein
 
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"George M. Middius" wrote in message
...


Robert Morein said:

I have a large stable of amplifiers which I use to modify the sound of

my speakers.

Are you sure you don't use them to modify your expectations?

Acoustat TNT-200 with KEF Reference III,
Bridged Hafler XL-280's to run NEAR 50ME and Polk LS15.
Parasound HCA2200ii


Do you have a permit to own three (or is it six?) overpriced and fully
functional amplifiers?

I have extras of each amplifier


Clearly you don't know the value of money. Nousiane could buy four
Brystons with 200-year warranties with the money you spent on your 22
cheesy amplifiers.

George, your response surprises me. Are you serious? Do you actually believe
that Bryston is defacto apriori sonically superior?
I think you're pulling my chain.


  #130   Report Post  
Robert Morein
 
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Default Audio amplifier design trivial?


"Arny Krueger" wrote in message
...
"Robert Morein" wrote in message


I'm a singular instance of "actually people".


Robert Morein certifies himself as having far better ears than any other
living human. That's why he does not need to educate himself by visiting
www.pcabx.com. He already knows in his mind that he can get a perfect

score
on every listening test there. Why waste time actually listening?

I choose my amps by listening.

I have a large stable of amplifiers which I use to modify the sound
of my speakers.


[snip]

This is the moral equivalent of one of those TV evangelist healing

services,
except that through the miracles of science, Bob has dispensed with the TV
evangelist and the TV.

I've VERY impressed. Good Job, Bob!

It's no great achievement.
These particular amplifiers sound quite different from each other.
I do not by that imply that all amplifiers are distinctly different.

I recommend the procedure to any audiophile.









  #131   Report Post  
Robert Morein
 
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Default Audio amplifier design trivial?


"Sockpuppet Yustabe" wrote in message
...

"Arny Krueger" wrote in message
...

Makes guys like Nousaine and I, who try to adjust our equalizers to get
better sound quality look pretty foolish, eh?


Clueless, as usual.

Quite clueless.
I have a bunch of parametric equalizers, but the effects which can be
obtained are not similar to the signatures of amplifiers.


  #132   Report Post  
Arny Krueger
 
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Default Audio amplifier design trivial?

"Robert Morein" wrote in message

"George M. Middius" wrote in message
...


Robert Morein said:

I have a large stable of amplifiers which I use to modify the sound of

my speakers.

Are you sure you don't use them to modify your expectations?

Acoustat TNT-200 with KEF Reference III,
Bridged Hafler XL-280's to run NEAR 50ME and Polk LS15.
Parasound HCA2200ii


Do you have a permit to own three (or is it six?) overpriced and
fully functional amplifiers?


I have extras of each amplifier


Clearly you don't know the value of money. Nousiane could buy four
Brystons with 200-year warranties with the money you spent on your 22
cheesy amplifiers.


George, your response surprises me. Are you serious?


The comment about 22 amplifiers 200 year warrantees didn't tip you off?

Do you actually believe that Bryston is defacto apriori sonically

superior?

Funny to see you acting so paranoid, Bob. Why would you care what a troll
like Middius thought about amplifiers?

I think you're pulling my chain.


Dooooh. Only a person naive enough to ask whether Middius was serious about
audio could have a second's doubt about that!


  #133   Report Post  
Arny Krueger
 
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Default Audio amplifier design trivial?

"Robert Morein" wrote in message

"Arny Krueger" wrote in message
...
"Robert Morein" wrote in message


I'm a singular instance of "actually people".


Robert Morein certifies himself as having far better ears than any
other living human. That's why he does not need to educate himself
by visiting www.pcabx.com. He already knows in his mind that he can
get a perfect score on every listening test there. Why waste time
actually listening?


I choose my amps by listening.


Irrelevant in this context.

I have a large stable of amplifiers which I use to modify the sound
of my speakers.


[snip]

This is the moral equivalent of one of those TV evangelist healing
services, except that through the miracles of science, Bob has
dispensed with the TV evangelist and the TV.


I've VERY impressed. Good Job, Bob!


It's no great achievement.


To say the least. It's an anti-achievement.

These particular amplifiers sound quite different from each other.


I'm sure that they look different and have different circuit diagrams.

I do not by that imply that all amplifiers are distinctly different.


Some are, some aren't.

I recommend the procedure to any audiophile.


Would that be your avoidance of blind listening tests that you recommend to
all audiophiles, Bob?


  #134   Report Post  
Arny Krueger
 
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Default Audio amplifier design trivial?

"Robert Morein" wrote in message

"Sockpuppet Yustabe" wrote in message
...

"Arny Krueger" wrote in message
...

Makes guys like Nousaine and I, who try to adjust our equalizers to
get better sound quality look pretty foolish, eh?


Clueless, as usual.

Quite clueless.
I have a bunch of parametric equalizers, but the effects which can be
obtained are not similar to the signatures of amplifiers.


Yes, the effects of adjustements to equalizers can be quite clearly audible
which is clearly different from what you get when you play musical chairs
with reasonably good amplifiers.


  #135   Report Post  
Robert Morein
 
Posts: n/a
Default Audio amplifier design trivial?


"Arny Krueger" wrote in message
...
"Robert Morein" wrote in message

"Arny Krueger" wrote in message
...
"Robert Morein" wrote in message


I'm a singular instance of "actually people".

Robert Morein certifies himself as having far better ears than any
other living human. That's why he does not need to educate himself
by visiting www.pcabx.com. He already knows in his mind that he can
get a perfect score on every listening test there. Why waste time
actually listening?


I choose my amps by listening.


Irrelevant in this context.

I have a large stable of amplifiers which I use to modify the sound
of my speakers.

[snip]

This is the moral equivalent of one of those TV evangelist healing
services, except that through the miracles of science, Bob has
dispensed with the TV evangelist and the TV.


I've VERY impressed. Good Job, Bob!


It's no great achievement.


To say the least. It's an anti-achievement.

These particular amplifiers sound quite different from each other.


I'm sure that they look different and have different circuit diagrams.

I do not by that imply that all amplifiers are distinctly different.


Some are, some aren't.

I recommend the procedure to any audiophile.


Would that be your avoidance of blind listening tests that you recommend

to
all audiophiles, Bob?

I don't avoid that anyone avoid blind listening tests.
However, when you've got two amps, I suggest switching them to see which one
is preferred.




  #136   Report Post  
Robert Morein
 
Posts: n/a
Default Audio amplifier design trivial?


"Arny Krueger" wrote in message
...
"Robert Morein" wrote in message

"Sockpuppet Yustabe" wrote in message
...

"Arny Krueger" wrote in message
...

Makes guys like Nousaine and I, who try to adjust our equalizers to
get better sound quality look pretty foolish, eh?


Clueless, as usual.

Quite clueless.
I have a bunch of parametric equalizers, but the effects which can be
obtained are not similar to the signatures of amplifiers.


Yes, the effects of adjustements to equalizers can be quite clearly

audible
which is clearly different from what you get when you play musical chairs
with reasonably good amplifiers.

The effects of adustment to equalizers can be quite audible.
My XL-280 and Acoustat TNT-200 sound as markedly different as many speakers.
This does not appear to be a property of the particular sample, since I have
three TNT-200 amps, and something like six XL-280's, and I've never noticed
a difference between samples of the same model.
The Parasound HCA-2200ii is similar to the TNT-200, but clearly preferable
with my Acoustat 2+2's.
My XL-600 amps, of which I have two, do not sound distinguishably different
from my XL-280's.
My Hafler P3000 is also distinguisable from the others, but not markedly so.


These amplifiers are distinguished by membership in three groups of circuit
topology:
1. zero output gain, source-follower MOSFET: XL-280, XL-600
2. grounded gate, three-gain stage MOSFET, trademarked Transnova topology:
TNT-200, TNT-120, P3000
3. four gain stage, mosfet driver, bipolar output: HCA-2200ii

The most marked difference in sound signature is between group one and the
other groups.

I advise anyone with the chance to sample multiple amplifiers to do so. In
my case, I have a dear friend who made this possible before I accumulated my
collection of amplifiers. I had the opportunity to listen to quite a few
others, before I selected these for permanent accumulation.







  #137   Report Post  
Robert Morein
 
Posts: n/a
Default Audio amplifier design trivial?


"Arny Krueger" wrote in message
...
"Robert Morein" wrote in message

"Arny Krueger" wrote in message
...
"Robert Morein" wrote in message


I'm a singular instance of "actually people".

Robert Morein certifies himself as having far better ears than any
other living human. That's why he does not need to educate himself
by visiting www.pcabx.com. He already knows in his mind that he can
get a perfect score on every listening test there. Why waste time
actually listening?


I choose my amps by listening.


[snip]


I would also mention that I have heard several Bryston amplifiers from the
80's and found them muddy and unrevealing.


  #138   Report Post  
George M. Middius
 
Posts: n/a
Default Audio amplifier design trivial?



Robert Morein said:

I have a large stable of amplifiers which I use to modify the sound of

my speakers.

Are you sure you don't use them to modify your expectations?

Acoustat TNT-200 with KEF Reference III,
Bridged Hafler XL-280's to run NEAR 50ME and Polk LS15.
Parasound HCA2200ii


Do you have a permit to own three (or is it six?) overpriced and fully
functional amplifiers?

I have extras of each amplifier


Clearly you don't know the value of money. Nousiane could buy four
Brystons with 200-year warranties with the money you spent on your 22
cheesy amplifiers.

George, your response surprises me. Are you serious? Do you actually believe
that Bryston is defacto apriori sonically superior?
I think you're pulling my chain.


Not your chain, somebody else's. Do you like pink noise? Do you get
lost in a lot of bass?



  #139   Report Post  
Sockpuppet Yustabe
 
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Default Audio amplifier design trivial?


"Robert Morein" wrote in message
...

"George M. Middius" wrote in message
...


Robert Morein said:

I have a large stable of amplifiers which I use to modify the sound of

my speakers.

Are you sure you don't use them to modify your expectations?

Acoustat TNT-200 with KEF Reference III,
Bridged Hafler XL-280's to run NEAR 50ME and Polk LS15.
Parasound HCA2200ii


Do you have a permit to own three (or is it six?) overpriced and fully
functional amplifiers?

I have extras of each amplifier


Clearly you don't know the value of money. Nousiane could buy four
Brystons with 200-year warranties with the money you spent on your 22
cheesy amplifiers.

George, your response surprises me. Are you serious? Do you actually

believe
that Bryston is defacto apriori sonically superior?
I think you're pulling my chain.



Yank




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  #140   Report Post  
trotsky
 
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Default Audio amplifier design trivial?



Robert Morein wrote:
"Arny Krueger" wrote in message
...

"Robert Morein" wrote in message


"Arny Krueger" wrote in message
...

"Robert Morein" wrote in message



I'm a singular instance of "actually people".

Robert Morein certifies himself as having far better ears than any
other living human. That's why he does not need to educate himself
by visiting www.pcabx.com. He already knows in his mind that he can
get a perfect score on every listening test there. Why waste time
actually listening?

I choose my amps by listening.


[snip]


I would also mention that I have heard several Bryston amplifiers from the
80's and found them muddy and unrevealing.



Were your screenplays ever described in a similar fashion?



  #141   Report Post  
Arny Krueger
 
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Default Audio amplifier design trivial?

"Robert Morein" wrote in message


I don't avoid that anyone avoid blind listening tests.


However, when you've got two amps, I suggest switching them to see
which one is preferred.


Or, if you have a PC with a good sound card and monitoring system, you can
do power-amp related DBTs by downloading files from
http://www.pcabx.com/product/amplifiers/index.htm . You can definitely hear
differences in power amps using files from these pages. If you can't you
probably need to upgrade your listening environment or have your ears
checked.

Three Bryston amps and three competitive amps are listed there for people's
listening pleasure. Power amp tests are tough, so I recommend that people
who are not familiar with the PCABX process start with the home page at
http://www.pcabx.com/index.htm .


  #142   Report Post  
Bob-Stanton
 
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Default Audio amplifier design trivial?

(John Atkinson) wrote in message . com...
(Audio Guy) wrote on r.a.h-e in message
...
Audio is a trivial application, they learn about power supply
design and amplification, which is pretty much all there is to
audio amplifiers, in their early years and then go on to much more
interesting and challenging concepts.


I see statements like this from time to time, yet I am not so sure
that audio design is "trivial." There are not many other design fields
where an amplifier: has to provide up to 30dB of voltage gain; act as a
voltage source into a wide and arbitrary range of load impedances
and do so in an unconditionally stable manner; have a passband noise
contribution at least 90dB down from 1W into 8 ohms, no matter what
its voltage gain and ultimate power delivery; have distortion
components under all load conditions that are below the threshold of
hearing no matter what the program material is; and do all the above
over at least three-decade, ie, a 10-octave passband.

Thoughts, gentlemen? I would suggest that designing, say, a typical RF
amplifier is, by comparison, "trivial" but, of course, I may just be
missing something :-)


I agree that designing a state of the art audio amplifier is not
trivial, for the reasons you stated above.

Designing an RF amplifier is more challenging than designing a audio
power amplifier. For example, a typical CATV RF amplifier would be 40
MHz - 1 GHz, and have 18 to 33 dB gain. Its' basic layout is very
similar to an audio power amplifier. The CATV amp will have: a couple
push-pull stages of bipolar transistors, a requirement for flat
response, and for very low second and third order distortion.

I don't think you would be suprised to hear that getting an amplifier
flat out to 1 GHz is more difficult than get an amplifier flat out to
20 kHz. In addition, CATV amplifiers are cascaded, (sometimes up to 50
amps in cascade). The sum total of the flatness of the cascade is
typically better than 2 dB. That works out to 1/25 dB flatness per
amplifier.

The visability of noise and distortion on video, are roughly the same
as the audibilty of noise and distortion for audio. But because noise
and distortion add in a cascade, the distortion performance of each
individual CATV amplifier must be better than that required for audio
amplifiers.

Stability of amplifiers that work up to a 1 GHz is more difficult to
achieve than for amplifiers that work only up to 20 KHz. Although RF
amps typically work into a 75 Ohm loads, they must be designed to be
stable into any load from a short circuit, to a complete open.

The list differences could go on, but if you pick up a textbook on
audio design, and one on RF design, you will see that the RF design is
or complex.

Bob Stanton
  #143   Report Post  
Robert Morein
 
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"Arny Krueger" wrote in message
...
"Robert Morein" wrote in message


I don't avoid that anyone avoid blind listening tests.


However, when you've got two amps, I suggest switching them to see
which one is preferred.


Or, if you have a PC with a good sound card and monitoring system, you can
do power-amp related DBTs by downloading files from
http://www.pcabx.com/product/amplifiers/index.htm . You can definitely

hear
differences in power amps using files from these pages. If you can't you
probably need to upgrade your listening environment or have your ears
checked.

Your results are of interest, but the combination of a particular amplifier
with a particular speaker are what concern the audiophile.
Nevetheless, I can't argue against the experience you provide, even though
it's useless for the purpose of choosing the combination.

Three Bryston amps and three competitive amps are listed there for

people's
listening pleasure. Power amp tests are tough, so I recommend that people
who are not familiar with the PCABX process start with the home page at
http://www.pcabx.com/index.htm .

An interesting education, which should force the conclusion that one should
test the intended amplifier/speaker combination together.


  #144   Report Post  
Arny Krueger
 
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"Robert Morein" wrote in message

"Arny Krueger" wrote in message
...
"Robert Morein" wrote in message


I don't avoid that anyone avoid blind listening tests.


However, when you've got two amps, I suggest switching them to see
which one is preferred.


Or, if you have a PC with a good sound card and monitoring system,
you can do power-amp related DBTs by downloading files from
http://www.pcabx.com/product/amplifiers/index.htm . You can
definitely hear differences in power amps using files from these
pages. If you can't you probably need to upgrade your listening
environment or have your ears checked.


Your results are of interest, but the combination of a particular
amplifier with a particular speaker are what concern the audiophile.


There are no *results* posted at
http://www.pcabx.com/product/amplifiers/index.htm . The results are formed
in people's minds after they listen to and carefully compare the audio
files.

Nevetheless, I can't argue against the experience you provide, even
though it's useless for the purpose of choosing the combination.


The tragic flaw in trying to match amplifiers and speakers is that the
audible flaws in speakers and rooms are like a California wild fire, and the
audible variations among good amplifiers are like garden hoses in
comparison. If you want speaker-sized audible differences you need some kind
of equalizer, not a merry-go-round full of power amps.

Three Bryston amps and three competitive amps are listed there for
people's listening pleasure. Power amp tests are tough, so I
recommend that people who are not familiar with the PCABX process
start with the home page at http://www.pcabx.com/index.htm .


An interesting education, which should force the conclusion that one
should test the intended amplifier/speaker combination together.


Just guessing here Bob, but I'll guess you ain't downloaded and listened to
squat from http://www.pcabx.com/product/amplifiers/index.htm .


  #145   Report Post  
Robert Morein
 
Posts: n/a
Default Audio amplifier design trivial?


"Arny Krueger" wrote in message
...
"Robert Morein" wrote in message

"Arny Krueger" wrote in message
...
"Robert Morein" wrote in message


I don't avoid that anyone avoid blind listening tests.

However, when you've got two amps, I suggest switching them to see
which one is preferred.


Or, if you have a PC with a good sound card and monitoring system,
you can do power-amp related DBTs by downloading files from
http://www.pcabx.com/product/amplifiers/index.htm . You can
definitely hear differences in power amps using files from these
pages. If you can't you probably need to upgrade your listening
environment or have your ears checked.


Your results are of interest, but the combination of a particular
amplifier with a particular speaker are what concern the audiophile.


There are no *results* posted at
http://www.pcabx.com/product/amplifiers/index.htm . The results are formed
in people's minds after they listen to and carefully compare the audio
files.

Nevetheless, I can't argue against the experience you provide, even
though it's useless for the purpose of choosing the combination.


The tragic flaw in trying to match amplifiers and speakers is that the
audible flaws in speakers and rooms are like a California wild fire, and

the
audible variations among good amplifiers are like garden hoses in
comparison. If you want speaker-sized audible differences you need some

kind
of equalizer, not a merry-go-round full of power amps.

Three Bryston amps and three competitive amps are listed there for
people's listening pleasure. Power amp tests are tough, so I
recommend that people who are not familiar with the PCABX process
start with the home page at http://www.pcabx.com/index.htm .


An interesting education, which should force the conclusion that one
should test the intended amplifier/speaker combination together.


Just guessing here Bob, but I'll guess you ain't downloaded and listened

to
squat from http://www.pcabx.com/product/amplifiers/index.htm .

The website has no use to me. A large variety of equipment becomes available
to me either as a free loan or at very low prices. Since I seek only to
optimize my own personal experience, your recorded samples are useless.

Nevertheless, since most audiophiles do not have access to the wide range of
equipment available to me, I suggest they listen to Arny's samples, and then
forget about them.





  #146   Report Post  
George M. Middius
 
Posts: n/a
Default Audio amplifier design trivial?



Gregipus Slanderus libeled:

Were your screenplays ever described in a similar fashion?


Out of bounds! Out of bounds!


  #147   Report Post  
Arny Krueger
 
Posts: n/a
Default Audio amplifier design trivial?

"Robert Morein" wrote in message

"Arny Krueger" wrote in message
...
"Robert Morein" wrote in message

"Arny Krueger" wrote in message
...
"Robert Morein" wrote in message


I don't avoid that anyone avoid blind listening tests.

However, when you've got two amps, I suggest switching them to see
which one is preferred.


Or, if you have a PC with a good sound card and monitoring system,
you can do power-amp related DBTs by downloading files from
http://www.pcabx.com/product/amplifiers/index.htm . You can
definitely hear differences in power amps using files from these
pages. If you can't you probably need to upgrade your listening
environment or have your ears checked.


Your results are of interest, but the combination of a particular
amplifier with a particular speaker are what concern the audiophile.


There are no *results* posted at
http://www.pcabx.com/product/amplifiers/index.htm . The results are
formed in people's minds after they listen to and carefully compare
the audio files.

Nevertheless, I can't argue against the experience you provide, even
though it's useless for the purpose of choosing the combination.


The tragic flaw in trying to match amplifiers and speakers is that
the audible flaws in speakers and rooms are like a California wild
fire, and the audible variations among good amplifiers are like
garden hoses in comparison. If you want speaker-sized audible
differences you need some kind of equalizer, not a merry-go-round
full of power amps.


Three Bryston amps and three competitive amps are listed there for
people's listening pleasure. Power amp tests are tough, so I
recommend that people who are not familiar with the PCABX process
start with the home page at http://www.pcabx.com/index.htm .


An interesting education, which should force the conclusion that one
should test the intended amplifier/speaker combination together.


Just guessing here Bob, but I'll guess you ain't downloaded and
listened to
squat from http://www.pcabx.com/product/amplifiers/index.htm .


The website has no use to me. A large variety of equipment becomes
available to me either as a free loan or at very low prices. Since I
seek only to optimize my own personal experience, your recorded
samples are useless.


Transparent attempt to deceptively avoid the level-matched, time-synched,
bias-controlled test issue.

Nevertheless, since most audiophiles do not have access to the wide
range of equipment available to me, I suggest they listen to Arny's
samples, and then forget about them.


Bob, it's quite clear that you're afraid of finding out that you've got
flesh-and-blood ears like the rest of us.

But thanks for confirming my speculation about your continued desire to
remain unnecessarily ignorant.

A lot of old hands have benefited from the PCABX experience, but there are a
lot of old dinosaurs who are still resisting it.


  #148   Report Post  
Robert Morein
 
Posts: n/a
Default Audio amplifier design trivial?


"Bob-Stanton" wrote in message
om...
(John Atkinson) wrote in message

. com...
(Audio Guy) wrote on r.a.h-e in message
...
Audio is a trivial application, they learn about power supply
design and amplification, which is pretty much all there is to
audio amplifiers, in their early years and then go on to much more
interesting and challenging concepts.


I see statements like this from time to time, yet I am not so sure
that audio design is "trivial." There are not many other design fields
where an amplifier: has to provide up to 30dB of voltage gain; act as a
voltage source into a wide and arbitrary range of load impedances
and do so in an unconditionally stable manner; have a passband noise
contribution at least 90dB down from 1W into 8 ohms, no matter what
its voltage gain and ultimate power delivery; have distortion
components under all load conditions that are below the threshold of
hearing no matter what the program material is; and do all the above
over at least three-decade, ie, a 10-octave passband.

Thoughts, gentlemen? I would suggest that designing, say, a typical RF
amplifier is, by comparison, "trivial" but, of course, I may just be
missing something :-)


I agree that designing a state of the art audio amplifier is not
trivial, for the reasons you stated above.

Designing an RF amplifier is more challenging than designing a audio
power amplifier. For example, a typical CATV RF amplifier would be 40
MHz - 1 GHz, and have 18 to 33 dB gain. Its' basic layout is very
similar to an audio power amplifier. The CATV amp will have: a couple
push-pull stages of bipolar transistors, a requirement for flat
response, and for very low second and third order distortion.

[snip]
I did some Google reading, and it appears that commercial CATV amplifier is
a very demanding case. However, design of a CATV amplifier has different
problems; it is not simply the case that it is more complex.
Were it not for the cascade requirement, one could make the case that the
audio amplifier is a greater challenge. In fact, I am not aware of any audio
amplifier ever produced that could meet the "analogous" CATV specs.
For an uncascaded RF amplifier, some characteristics of the problem are
relaxed compared to the audio amp.
Since the RF amplifier is not baseband, distortion in the signal does not
appear directly in the modulated signal. Even with simple class AB designs,
very high power output can be obtained with a small component count, since
the distortion products are broadband and not concentrated around the
carrier. By contrast, since the audio amplifier is a baseband instrument,
the distortion products are largely concentrated in the passband.

CATV amplifiers operate into a controlled impedance. The requirement that
they must survive a short is not equivalent to the challenge which audio
amplifiers encounter, where the load is an electrodynamic mechanical system
that provides a load to the system which is a function of frequency, and,
when accounting for nonlinear effects, amplitude and mechanical state.

If an audio amplifier were required to meet a spec with 50 of them in
cascade, we would see much more of the Halcro level of engineering.







  #149   Report Post  
S888Wheel
 
Posts: n/a
Default Audio amplifier design trivial?

Bob said


I choose my amps by listening.


Arny said


Irrelevant in this context.


That just about says it all.
  #150   Report Post  
Arny Krueger
 
Posts: n/a
Default Audio amplifier design trivial?

"S888Wheel" wrote in message

Bob said


I choose my amps by listening.


Arny said


Irrelevant in this context.


That just about says it all.


In this case, it's yet another example of sockpuppet wheel's ignorance of
the importance of context.




  #151   Report Post  
ScottW
 
Posts: n/a
Default Audio amplifier design trivial?


"Arny Krueger" wrote in message
...
"S888Wheel" wrote in message

Bob said


I choose my amps by listening.


Arny said


Irrelevant in this context.


That just about says it all.


In this case, it's yet another example of sockpuppet wheel's ignorance of
the importance of context.


Like when you characterized one of my simple statements as whining. That
lack of context?
Incorrigible hypocrite.

ScottW


  #152   Report Post  
S888Wheel
 
Posts: n/a
Default Audio amplifier design trivial?

Bob said


I choose my amps by listening.




Arny said


Irrelevant in this context.


I said


That just about says it all.


Arny said


In this case, it's yet another example of sockpuppet wheel's ignorance of
the importance of context.


Nope. Just me finding a specific exchange that serindipidously symbolizes the
big picture. You just didn't get it.
  #153   Report Post  
Arny Krueger
 
Posts: n/a
Default Audio amplifier design trivial?

"ScottW" wrote in message
news:vJcnb.43010$gi2.790@fed1read01
"Arny Krueger" wrote in message
...
"S888Wheel" wrote in message

Bob said


I choose my amps by listening.

Arny said


Irrelevant in this context.


That just about says it all.


In this case, it's yet another example of sockpuppet wheel's
ignorance of the importance of context.


Like when you characterized one of my simple statements as whining.


Hey, it was simple whining.

That lack of context?


Where's your proof, Scott?

Incorrigible hypocrite.


Whatever.

ScottW



  #154   Report Post  
Robert Morein
 
Posts: n/a
Default Audio amplifier design trivial?


"Arny Krueger" wrote in message
...
"S888Wheel" wrote in message

Bob said


I choose my amps by listening.


Arny said


Irrelevant in this context.


That just about says it all.


In this case, it's yet another example of sockpuppet wheel's ignorance of
the importance of context.

There's no distortion. It's a good summary.


  #155   Report Post  
Bob-Stanton
 
Posts: n/a
Default Audio amplifier design trivial?

"Robert Morein" wrote in message


I did some Google reading, and it appears that commercial CATV amplifier is
a very demanding case. However, design of a CATV amplifier has different
problems; it is not simply the case that it is more complex.
Were it not for the cascade requirement, one could make the case that the
audio amplifier is a greater challenge. In fact, I am not aware of any audio
amplifier ever produced that could meet the "analogous" CATV specs.
For an uncascaded RF amplifier, some characteristics of the problem are
relaxed compared to the audio amp.


That's right, they have a different set of problems. There is a hidden
complexity in RF circuits. A componet at audio frequencies is simple
single impedance. At RF a resistor is a network of three componets
(resistance, lead inductance, body capacitance). All these


  #158   Report Post  
Bob-Stanton
 
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Default Audio amplifier design trivial?

"Robert Morein" wrote in message

CATV amplifiers operate into a controlled impedance. The requirement that
they must survive a short is not equivalent to the challenge which audio
amplifiers encounter, where the load is an electrodynamic mechanical system
that provides a load to the system which is a function of frequency, and,
when accounting for nonlinear effects, amplitude and mechanical state.


Yes, a speaker systems provide a load that is a complex impedance, and
one that can change slightly due to nonlinear effects.

The RF amplifer can see a greater load variation. It must of stable
with an accidental low impedance (short) located anywhere along the
transmission line. RF amps are typically tested by sliding a low
impedance (about 1 Ohm) along a sloted line, on the output of the
amplifier. Here is the impedance variation the RF amplifier sees as
the resistor is moved along the sloted line:

Wavelengths Impedance

0.025 1.0 +j 12
0.050 1.1 +j 25
0.075 1.2 +j 38
0.100 1.5 +j 55
0.125 2.0 +j 75
0.150 2.9 +j 103
0.175 4.9 +j 147
0.200 10.5 +j 230
0.225 40.6 +j 470
0.250 5625.0 +j 0.00
0.275 40.6 -j 470
0.300 10.5 -j 230
0.325 4.9 -j 147
0.350 2.9 -j 103
0.375 2.0 -j 75
0.400 1.5 -j 55
0.425 1.2 -j 38
0.450 1.1 -j 25
0.475 1.0 -j 12
0.500 1.0 -j 0.00


This variation of impedance (going from short, to inductive, to open,
to capacitive) is much greater than an audio amplifier would ever see
from and electrodynamic mechanical nonlinear system.

Bob Stanton
  #160   Report Post  
Sander deWaal
 
Posts: n/a
Default Audio amplifier design trivial?

(Bob-Stanton) said:

I once a had preamp with 'hum' problem. No matter how well I
redesigned the power supply the hum was always their. Finally I went
out an got some batterys and powered the preamp from pure DC. Still
got the hum! That was the clue. It wasn't hum, it was recified video
sync pulses. They sounded like 60 cps hum.
(P.S. It was 60 cps, (not 60 Hz) back then.) :-)


Geez Bob, you're from the Ampex era? :-)

It was easily cured by puting RFI filters on the AC lines and on the
phono input lines.


Ah yes, but this "solution" poses another problem.
We have the same thing going on over here in Europe, first with the
German TÜV regulations, and nowadays with the CE EMC regulations.
Literally EVERY manufacturer puts some ceramic capacitors over the in-
and outputs, thereby trading sound quality for EMC immunity.
There are better ways to do this, however.
Using polystyrene caps and ferrite beads for instance.
Also, it is my experience that tube electronics are far more immune to
EMC problems than solid state electronics.
One can also design on inherent immunity for high frequency rubble,
even with solid state stuff, but almost no one does so.

BTW, I'm curious as to how the video sync pulses came into the
amplifier circuit.
Was it just strong radiation of harmonics and detection by the
amplifier, or was it pure superimposition on the supply lines?

--
Sander deWaal
Vacuum Audio Consultancy
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