Choosing an amp on the basis of tone.....

[rigma]

Bill---

"Posted to 2-Channel Audio (Forum) by mdeneen on February 5, 2002"

I believe most of those quotes pulled from a long ago thread are mine - as you can see from 2002. When I started JuicyMusic in 2003, I had the rare opportunity as an engineer to start with a clean sheet of paper on all the designs I would attempt. The BlueBerry for example, which has a fine reputation with audiophiles and reviewers too, is a no feedback amplifier. It came about after building perhaps a dozen circuits of trial and error. The Peach and Merlin and the pCATs are also incremental applications of this new understanding. Each product I have designed leads me to new understandings. Many times there are half a dozen failures or rejects in between designs which come to market. Those are all learning experiences.

The most enriching aspect of my little business is that it creates a very extended personal learning opportunity for me - a path to develop my own personal understanding. Quite frankly, I am very proud of not being stuck building the same old golden age amplifiers from my grandpa's day. I am delighted to challenge my mind and my thinking to be open to new possibilities each and every day I am in my lab. This matches my general quest to be a life-long learner in all areas, and not doomed to simply repeat the same 4 bars in an endless boogie. I used to wear bell bottoms too, if that's interesting for folks to know. The one thing I don't make apologies for is learning.

Great post! My view also. In contrast to

" We

tend to stay within the limits thus set by the existing paradigms and

to resist changes that threaten one's viewpoint of the world. When

someone else creates challenges to the paradigms, it is normal

also to try to protect one's world view by preventing the new idea from

gaining ground."

Care to guess who that sounds like? Does anyone really need a hint?

rigma

[Lascaladan]

I had some of these amps(M22) as well as the higher powered M25. I thought, at the time, they were fabulous. I used them with many speakers:Cornwalls, Allison 1s,DQ10s just to name a few. They were never the weak link in my system. However, like many Japanese amps, they have many protection circuits(and many parts)that today, in my opinion, will not capture my attention as they did yesteryear. They seem to have high pricing on the used market(EBAY,AUDIOGON). Very solid musical foundation. Huge, stiff power supplies, and good parts. They were produced to go against Mac. Actually, better, imo.(Just an opinion). There are so many good amps out there. As some of you know already, I am in the SS camp, for many of "my own" reasons. I do not believe measurements can tell you how an amp sounds. I judge it all on listening. I also feel when evaluating a piece of equipment, it must be the only piece in the system that changes, so you know it just this one piece that is "different". Changes to room acoustics and set up have given me as much difference, many times, more, that changing out 2 excellent amps. I use silver speaker wire, which I received from England, which totally "opened up" my listening window, putting to shame my larger gauge, more expensive "audiophile" cable. However, I did double up my runs, as to the listening levels I enjoy, did make a major difference. The point I am making is this. To each his own. Listen as the final judgement. Enjoy!

[Parrot]

Good essay. Everything I've discovered over the past few years is in agreement. All the attributes which naturally lower distortion improve the tone of amplifiers. The three most important being only Class A operation, no feedback, and all devices operated only in the natural range with well mated impedances and loads. Feedback is very useful in servo and control applications, but never in amplifiers for audio. It can not and does not improve tone, but only improves objective measurements. One thing is certain about negative feedback, when it arrives at the input, it is already the wrong signal. See "Phase Distortion."

The popularity of zero feedback amplification is growing slowly and steadily. It's still a cult item (i.e. BlueBerry, many SET amps, pCATs, and others), but growing is better than shrinking. Even the avant guard SS designers are now seeing the light and attempting to design SS amplification with no feedback, and using Single Ended topologies. Meanwhile, the M.O.R. and mainstream designs are still obsessed with artificial objectivity through forcing circuits to have low distortion measurements by apply massive negative feedback.

Mobile - RE: No Feedback - TSK, TSk, c'mon - you

didn't read what I said. I said it was not a panacea, and it ain't.

Yes, it HAS benefits in some designs and in some cases. It's a great

sound, it might be just what someone likes, but it is not a universal.

Like all design elements - there is no free lunch. You are trading one

benefit at the expense of others. Look, horns are not a panacea, nor

are tubes or SET or no feedback or EICO 81's. They are incorporations

of differing tradeoffs. Otherwise, there would be only one system.

And

are you implying "I" haven't listened to these things? I have built

several amps and preamps with no feedback. I would say I have some

first-hand experience with the performance tradeoffs and the sound.

There are times I like that sound and times I don't. Sounds good on

some speakers, not as good on others. Improves the mids but the lows

suffer. Improves openness as the expense of distortion of tone. What's

hard to grasp about that? Also, let's be VERY clear that there is a

substantial difference between "global feedback" and "local feedback,"

and lest anyone is kidding themselves, the "no feedback" designs DO use

feedback, only locally.

If I had speakers with actual bass,

which means not classic Klispch speakers, and I wanted a full-range

tube amp to drive them, I'd probably opt for a design that had enough

feedback to extend the FR into the bass region. If I was bi-amping with

a tube amp for HF horns or something, than the "local FB only" designs

might work very well or better. So sure, if you have Heresey or LS or

CWs and you are not using a sub, what's the difference if there is no

LF response in the amp? If there's no bass, you don't have to worry

much about no bass.

I don't think the dogma routine really works

for tube types, circuit topology, driver types. wire, or anything else.

There are good systems and bad ones. Carefully constructed compromises

and carelessly constructed ones.

People take the dogma - such

as eliminate feedback, then they modify a circuit which was never

intended to operate that way, hear a lot of "euphonic" effects, and

proclaim it is a universal fix. I know there are some SET amps which

have 5% 2nd order harmonic distortion - very euphonic - and people

swoon over this. Other people can actually hear the tonal effects of 5%

distortion and think it sucks. So? I guess the dogma is more fun?

As

for the EICO 81 - - ok, maybe it's the greatest sounding amplifier ever

known to mankind, and the "only" amplifier that any rational listener

will ever need. Or, maybe it's the "only" amplifier anyone in their

right mind should connect to Cornwalls. Or, maybe only the one YOU have

sounds that way. Or maybe it's just one of many nice sounding

integrated tube amps of the 60's. Doesn't matter. Listeners have

differing tastes, differing goals and it's a big, BIG world out there.

I've heard - although unconfirmed - that people can even get sick of

BigMacs - go figure.

For convenience, I've put the two posts together, to save on scrolling.

Present day thinking: "Feedback is very useful in servo and control applications, but never in

amplifiers for audio. It can not and does not improve tone, but only

improves objective measurements."

Earlier thinking: "I have built

several amps and preamps with no feedback. I would say I have some

first-hand experience with the performance tradeoffs and the sound.

There are times I like that sound and times I don't. Sounds good on

some speakers, not as good on others. Improves the mids but the lows

suffer. Improves openness as the expense of distortion of tone. What's

hard to grasp about that?"

Another point that is difficult to reconcile:

Earlier thinking: "Also, let's be VERY clear that there is a

substantial difference between "global feedback" and "local feedback,"

and lest anyone is kidding themselves, the "no feedback" designs DO use

feedback, only locally."

But present day reference is to "no feedback." Does this mean "no feedback" or does it mean "local feedback"?

Also I can't help but note the slams against classic Klipsch speakers and SET amps in the earlier post but don't know if these, too, have been rendered inoperative by virtue of continuing learning.

[Parrot]

It is however, really sad that some people will do anything to prevent alternative views from even being displayed for others to consider.

Interesting. I've never seen this done and I've been on the Forum almost as long as you. Why, in this very thread, I've even gone so far as to display alternative views from one person!

[oldbuckster]

Maybe I'm off the mark here, won't be the first time..............................In the End, all that matters is what the person who spent the money on the amp thinks..............his money, his ears, his taste..................there are so many different type people on this forum, with different tastes, I don't think you will get total agreement on ANY thing here..................I thought this was a simple hobby to get into.........................Boy, was I WRONG..................

================

Oldbuckster-

I can only speak for myself here. I am not trying to "get everyone's agreement" or even "change anyone's mind." I think the purpose of a hobby forum is to explore all aspects of the hobby, and that is what I see this thread to be about. Some folks are asking questions, others are thinking of maybe trying some new ideas, and others are firmly planted in 1952. All those are fine positions - part of the hobby. If we didn't post about the depth, breath and possibilities of the hobby, there would be no interest, no posts and eventually no forum. Thisw is not an arm twisting contest. It is however, really sad that some people will do anything to prevent alternative views from even being displayed for others to consider.

I understand that, and you make your point well......................I am the one with the problem, I thought this was a simple hobby, but it is not. it's not that you can talk about amps.............it's WHAT KIND OF AMP, SET, VRD, Solid State...............before you even start................Speakers, stock speakers, modded speakers, traxhorn speakers.....................yikes, I won't even get into turntables............It's just a bigger hobby than I thought, I really wasn't prepared to grasp all that is found in this hobby...............I thought a Cd player is a Cd player, didn't realize there is stock CD players, modded CD players, and even tubed CD players..................I came here "blind" and now my eyes are wide open..............I have stated this many, many times, "I didn't realize my stereo sucked untill I joined this Forum".......................Enough said.......................

[DrWho]

Dr. Who---
I think in the end what counts is the acoustic frequency response of the amplifier+speaker. What happens when the impedance of a driver rises?

Agreed - not sure what your question is asking though...

[oldbuckster]

oldbusckster---

Just enjoy the ride. Afterall, everyone's stereo sucks, right? We just obsess about it, where the "civilians" out there turn the volume knob and just enjpy the music. Hobbies are just something to do with your time - it ain't life or death.

Your right.................the Music means more to me than equipment............Music is the magic, the equipment just reproduces the music......

[Parrot]

Old Buck,

Why drive a Porsche when any old car will get you down the road? Driving is the fun part, having a car just let's you do it.

[sfellini]

Old Buck,

Why drive a Porsche when any old car will get you down the road? Driving is the fun part, having a car just let's you do it.

You mean, like this one?

[coda]

Review du jour, Cary Audio CAD-805

Dick Olsher & Various January 1994

Sam Tellig March 1998

Measurements

[Parrot]

For an enjoyable read about Tellig, Dudley, and Atkinson, check out

http://www.randi.org/jr/120304youve.html

[edwinr]

Old Buck,

Why drive a Porsche when any old car will get you down the road? Driving is the fun part, having a car just let's you do it.

That's remarkably profound, Paul. I'm impressed! []

[oldbuckster]

Old Buck,

Why drive a Porsche when any old car will get you down the road? Driving is the fun part, having a car just let's you do it.

Because I can........................Why do you need Klipsch speakers, when other speakers do the same thing, they reproduce music too? No seriously Parrot, this hobby is much deeper than I ever thought possible, can become quite costly, and quite frankly, I think I have reached my limit on how deep to jump in, modding speakers, rolling tubes, tubed CD players, thousands of dollars for Record playing equipment, I am beginning to see this is out of my league..................It's the GOOD people on this forum that keeps me here, not the equipment. There are many good ideas shared here, information, a helping hand from time to time, folks seem to care here, and that means more to me than what equipment to buy.

PARROT, by the way...................I'm fixin' to buy that NEW Bob Dylan Album............Go Figure..................My opinion hasn't changed though...........

[oldbuckster]

Old Buck,

Why drive a Porsche when any old car will get you down the road? Driving is the fun part, having a car just let's you do it.

sorry,double post.................Driving ISN'T fun, the Fun is the CAR your driving..............

[maxg]

Good essay. Everything I've discovered over the past few years is in agreement. All the attributes which naturally lower distortion improve the tone of amplifiers. The three most important being only Class A operation, no feedback, and all devices operated only in the natural range with well mated impedances and loads. Feedback is very useful in servo and control applications, but never in amplifiers for audio. It can not and does not improve tone, but only improves objective measurements. One thing is certain about negative feedback, when it arrives at the input, it is already the wrong signal. See "Phase Distortion."

The popularity of zero feedback amplification is growing slowly and steadily. It's still a cult item (i.e. BlueBerry, many SET amps, pCATs, and others), but growing is better than shrinking. Even the avant guard SS designers are now seeing the light and attempting to design SS amplification with no feedback, and using Single Ended topologies. Meanwhile, the M.O.R. and mainstream designs are still obsessed with artificial objectivity through forcing circuits to have low distortion measurements by apply massive negative feedback.

Mobile - RE: No Feedback - TSK, TSk, c'mon - you didn't read what I said. I said it was not a panacea, and it ain't. Yes, it HAS benefits in some designs and in some cases. It's a great sound, it might be just what someone likes, but it is not a universal. Like all design elements - there is no free lunch. You are trading one benefit at the expense of others. Look, horns are not a panacea, nor are tubes or SET or no feedback or EICO 81's. They are incorporations of differing tradeoffs. Otherwise, there would be only one system.

And are you implying "I" haven't listened to these things? I have built several amps and preamps with no feedback. I would say I have some first-hand experience with the performance tradeoffs and the sound. There are times I like that sound and times I don't. Sounds good on some speakers, not as good on others. Improves the mids but the lows suffer. Improves openness as the expense of distortion of tone. What's hard to grasp about that? Also, let's be VERY clear that there is a substantial difference between "global feedback" and "local feedback," and lest anyone is kidding themselves, the "no feedback" designs DO use feedback, only locally.

If I had speakers with actual bass, which means not classic Klispch speakers, and I wanted a full-range tube amp to drive them, I'd probably opt for a design that had enough feedback to extend the FR into the bass region. If I was bi-amping with a tube amp for HF horns or something, than the "local FB only" designs might work very well or better. So sure, if you have Heresey or LS or CWs and you are not using a sub, what's the difference if there is no LF response in the amp? If there's no bass, you don't have to worry much about no bass.

I don't think the dogma routine really works for tube types, circuit topology, driver types. wire, or anything else. There are good systems and bad ones. Carefully constructed compromises and carelessly constructed ones.

People take the dogma - such as eliminate feedback, then they modify a circuit which was never intended to operate that way, hear a lot of "euphonic" effects, and proclaim it is a universal fix. I know there are some SET amps which have 5% 2nd order harmonic distortion - very euphonic - and people swoon over this. Other people can actually hear the tonal effects of 5% distortion and think it sucks. So? I guess the dogma is more fun?

As for the EICO 81 - - ok, maybe it's the greatest sounding amplifier ever known to mankind, and the "only" amplifier that any rational listener will ever need. Or, maybe it's the "only" amplifier anyone in their right mind should connect to Cornwalls. Or, maybe only the one YOU have sounds that way. Or maybe it's just one of many nice sounding integrated tube amps of the 60's. Doesn't matter. Listeners have differing tastes, differing goals and it's a big, BIG world out there. I've heard - although unconfirmed - that people can even get sick of BigMacs - go figure.

For convenience, I've put the two posts together, to save on scrolling.

Present day thinking: "Feedback is very useful in servo and control applications, but never in amplifiers for audio. It can not and does not improve tone, but only improves objective measurements."

Earlier thinking: "I have built several amps and preamps with no feedback. I would say I have some first-hand experience with the performance tradeoffs and the sound. There are times I like that sound and times I don't. Sounds good on some speakers, not as good on others. Improves the mids but the lows suffer. Improves openness as the expense of distortion of tone. What's hard to grasp about that?"

Another point that is difficult to reconcile:

Earlier thinking: "Also, let's be VERY clear that there is a substantial difference between "global feedback" and "local feedback," and lest anyone is kidding themselves, the "no feedback" designs DO use feedback, only locally."

But present day reference is to "no feedback." Does this mean "no feedback" or does it mean "local feedback"?

Also I can't help but note the slams against classic Klipsch speakers and SET amps in the earlier post but don't know if these, too, have been rendered inoperative by virtue of continuing learning.

Very early on in my career on this forum I decided a tag line that would cover my *** would be a good idea.

If I look at my early posts and my later posts I think I have moved far more than Mark in a similar time period. Thankfully - my sig says I can.

I think I might start renting it out for some of the longer serving members.....

[Erik Mandaville]

What about factors such as....

-physical weight of the component

-its exterior dimensions

-it's overall aesthetic appeal

-cost

Are any of the above important elements, or should one's primary concern focus on performance (tone being one of those) and how well the piece integrates with the rest of the system.

...past history on this forum would suggest that 'tone' and other aspects of performance were not enough for some reason.

Erik

[3dzapper]

Old Buck,

Why drive a Porsche when any old car will get you down the road? Driving is the fun part, having a car just let's you do it.

Because I can........................Why do you need Klipsch speakers, when other speakers do the same thing, they reproduce music too? No seriously Parrot, this hobby is much deeper than I ever thought possible, can become quite costly, and quite frankly, I think I have reached my limit on how deep to jump in, modding speakers, rolling tubes, tubed CD players, thousands of dollars for Record playing equipment, I am beginning to see this is out of my league..................It's the GOOD people on this forum that keeps me here, not the equipment. There are many good ideas shared here, information, a helping hand from time to time, folks seem to care here, and that means more to me than what equipment to buy.

PARROT, by the way...................I'm fixin' to buy that NEW Bob Dylan Album............Go Figure..................My opinion hasn't changed though...........

OB, You've been around here long enough to notice that there is a strong contingent that advocates getting the most fidelity from the least outlay. Some of us do go a bit over the top. Myself, I've been accused of having more money than brains and I don't have much money;^)

But then, I enjoy building and tinkering with things although the thinking, planning and dreaming are often more rewarding than the actual ends.

If you enjoy your system and it helps relieve the pressures of the world, you've got it made!

Rick

[Parrot]

Very early on in my career on this forum I decided a tag line that would cover my *** would be a good idea.

If I look at my early posts and my later posts I think I have moved far more than Mark in a similar time period. Thankfully - my sig says I can.

I think I might start renting it out for some of the longer serving members.....

There is a big difference between changing one's opinions (what one believes to be so) and changing the facts (what is so). We're dealing with both here. Factual contradictions cannot be reconciled or just skipped over and explained away as changing one's mind.

[3dzapper]

Very early on in my career on this forum I decided a tag line that would cover my *** would be a good idea.

If I look at my early posts and my later posts I think I have moved far more than Mark in a similar time period. Thankfully - my sig says I can.

I think I might start renting it out for some of the longer serving members.....

There is a big difference between changing one's opinions (what one believes to be so) and changing the facts (what is so). We're dealing with both here. Factual contradictions cannot be reconciled or just skipped over and explained away as changing one's mind.

"People take the dogma - such as eliminate feedback, then they modify a circuit which was never intended to operate that way, hear a lot of "euphonic" effects, and proclaim it is a universal fix. I know there are some SET amps which have 5% 2nd order harmonic distortion - very euphonic - and people swoon over this. Other people can actually hear the tonal effects of 5% distortion and think it sucks. So? I guess the dogma is more fun? "

Besides giving MH a dig for his "perfect by God" HF-81 in the ensuing paragraph, the above statement is 100% accurate. Some "purists" have modified their ultralinear amps, mostly Dynacos, by running in pseudo-triode mode and removing feedback to the point of excessive distortion. These amps were never engineered to run with zero feedback as they were inherently unstable. True, modern designs and components can reduce the amount of feedback required for stability, bandwidth and tone the key word here-in reduce.

It is quite another thing entirely to engineer from the ground up a zero feedback true triode, high gain circuit, carefully selecting components to allow full frequency response in a stable design. I know that I am unable to engineer such a feat Mr Parrot, can you? Can your Patron Saint?

In short, can it!

Rick

[pauln]

Very early on in my career on this forum I decided a tag line that would cover my *** would be a good idea.

If I look at my early posts and my later posts I think I have moved far more than Mark in a similar time period. Thankfully - my sig says I can.

I think I might start renting it out for some of the longer serving members.....

There is a big difference between changing one's opinions (what one believes to be so) and changing the facts (what is so). We're dealing with both here. Factual contradictions cannot be reconciled or just skipped over and explained away as changing one's mind.

I've never liked the word "fact". If you think about it, there are no facts - to beleive so boasts a smug certainty and assumes a right knowledge of some aspect of objective reality. We don't have certain knowledge of reality. Similarly in the way we improperly use the word "law", as in the laws of physics; all observed ordered ralations are described by theories always subject to revision, not laws. An instance is held up as a fact when one beleives their opinion about it can not be logically contested, but historically this position has been demonstrated over and over to be in error. Facts are indeed opinions; opinions are not facts - there are no facts.

"In theory there is no difference between theory and practice. In practice there is." Yogi Berra