Amplifier design: Truths or Myths?

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6BQ5

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Amplifier design: Truths or Myths?
« on: 28 Jul 2008, 12:54 am »
The story goes that audio-legend Paul Klipsch wore a button under his lapel that said Bullsxxt. He would flash it to someone who would engage with him on some audio-related topic (when appropriate of course).

I'm not at all an engineer, but like to read and learn to educate myself the gear I use and how they work (Roger's product manuals are great that way).

Over the years, I've come across various statements frequently made on discussion boards regarding amplifier design. As with all things, there is a bit of truth and some B.S. with each in the list below. These are NOT my ideas. Curious as to what others think ...

1.   Transformers: The bigger “iron”, the better, hence massive power supplies and output transfers sound best.

2.   Rectification: Tube rectification is better than diode, preferably with a choke in PS

3.   Tubes: NOS is generally better than today's Chinese, Russian, Czech and former Yugo production. It's more than just testing well.

4.   Parts I - Caps : Good ol’ Sprague caps sound better than new expensive exotics

5.   Parts II - Materials: Silver is better if you can afford it. Silver transformers, wiring, etc…

6.   Design: Fewer stages the better

7.   Negative Feedback: Preferably none. Zero NFB is best

8.   Design II: Class A … nuff said, generally sounds better than AB, B and other variants

9.   Construction: Hand wired is generally better than PCB

10.   Straight wire with gain : Tone controls are generally bad, another complexity to degrade the signal from "purity"

11.  Transformer II: Transformer-coupled amps perform better than those using a cap between stages

12.  Made in the USA: The Chinese don't care about quality of products. Made in the USA is best if you want your amp to last.

I would say with all of these, its a matter of implementation, thus "generalized" statements are mostly untrue. However, what is the "real story" with these? They can't be entirely right or wrong either.


jeffreybehr

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Re: Amplifier design: Truths or Myths?
« Reply #1 on: 28 Jul 2008, 06:14 am »
Hmm...FWIW, I'll add my 2 cents worth.

3. Few current-production tubes sound even acceptable, much less good or better.  Of course there are exceptions.

4. Modern caps, especially the better film caps, do indeed sound better...quicker, cleaner, less edgy...than the old ones.

6, 7, and 8. I agree, as my favorite-sounding amps are SETs, by definition class-A amps, and those that sound best to me have no NFB.

As I said, FWIW.   :?

andrewbee

Re: Amplifier design: Truths or Myths?
« Reply #2 on: 28 Jul 2008, 02:23 pm »
When I read the original post I wish I had one of those BS badges now :lol:
I don't particularly agree with any of the 12 points.
Everything must be taken in context.
I saw your disclaimer 6BQ5 so I know you are writing what you have read.
Now you need to learn to separate the wheat from the chaff.

richidoo

Re: Amplifier design: Truths or Myths?
« Reply #3 on: 28 Jul 2008, 04:49 pm »
Audio is a religion full of dogma. With big money and big pride involved people try to get a leg up by inventing myths to hook consumers who navigate the waters using only "common sense." When believed, myths become reality. Audio technology is more subtle than common sense can comprehend but understanding isn't as much fun as believing, so suckers fall for the easy explanations then defend the myths and their pride. Developing an understanding of the technology will go a long way toward protecting you from the trappings of audio dogma, as will listening and experimenting for yourself.

6BQ5

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Re: Amplifier design: Truths or Myths?
« Reply #4 on: 28 Jul 2008, 07:20 pm »

Audio is a religion full of dogma.

No argument there. Ditto.


Developing an understanding of the technology will go a long way toward protecting you from the trappings of audio dogma, as will listening and experimenting for yourself.

That's the hard part, and why I started this thread!!!     :scratch:

I don't have the expertise, time and money to be testing transformers, caps, NOS tubes to come to my own conclusions. Thus I rely on other people's knowledge to help guide me.

There are people out there who make a living designing amplifiers, who are indeed, in a much better position to shed light on what is myth and reality, fact from fiction.

It just seems few people are willing to stick their neck out to set the record straight.




satfrat

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Re: Amplifier design: Truths or Myths?
« Reply #5 on: 28 Jul 2008, 07:49 pm »



It just seems few people are willing to stick their neck out to set the record straight.





IF you are actually concerned about those knowledgable in amplifier design sticking their knees out, why would you place this topic in a particular manufacturer's Circle? :scratch: This topic would be better served in a neutral Circle such as Audio Central where toes can't be stepped on and varied opinions can be openly shared. 8)

Cheers,
Robin


bpape

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Re: Amplifier design: Truths or Myths?
« Reply #6 on: 28 Jul 2008, 08:02 pm »
Maybe he posted here because he was hoping Roger, as a well respected, no-nonsense designer would answer...

Bryan

6BQ5

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Re: Amplifier design: Truths or Myths?
« Reply #7 on: 28 Jul 2008, 08:06 pm »
Given I own and RM-10 MKII and RM-5 MK III, certainly Roger's expertise would carry a lot if weitht.

But, other opinions are certainly welcome.  :D


satfrat

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Re: Amplifier design: Truths or Myths?
« Reply #8 on: 28 Jul 2008, 08:10 pm »
Maybe he posted here because he was hoping Roger, as a well respected, no-nonsense designer would answer...

Bryan

Well that kinda goes w/o saying Brian. :lol: But when he specifically asked by so few folks were willing to stick their necks out, it suggested he was looking for more than just Roger's thoughts. I just thought he might get more responses in an open Circle,,, just like a variety of responses are generated from acoustic issues in the Acoustic Circle. Sound logical to you? :D

Cheers.
Robin
« Last Edit: 29 Jul 2008, 01:02 am by satfrat »

satfrat

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Re: Amplifier design: Truths or Myths?
« Reply #9 on: 28 Jul 2008, 08:19 pm »
But, other opinions are certainly welcome.  :D



Maybe so,,, maybe not. Are you welcoming other amp designers to freely post their design ideas & philosophies here? I don't know about that, do you? :D

Cheers,
Robin

bpape

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Re: Amplifier design: Truths or Myths?
« Reply #10 on: 28 Jul 2008, 08:22 pm »
Maybe he posted here because he was hoping Roger, as a well respected, no-nonsense designer would answer...

Bryan

Well that kinda goes w/o saying Brian. :lol: But when he specifically asked by so few folks were willing to stick their necks out, it suggested he was looking for more than just Marks thoughts. I just thought he might get more responses in an open Circle,,, just like a variety of responses are generated from acoustic issues in the Acoustic Circle. Sound logical to you? :D

Cheers.
Robin

Understand Robin.  Thought maybe he was looking to Roger specifically due to owning the equipment. I'll agree that if he want's open discussion and everyone's opinion, the other circles would be a better place.

Bryan

GMuffley

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Re: Amplifier design: Truths or Myths?
« Reply #11 on: 28 Jul 2008, 08:26 pm »
I can think of examples that will counter each of the first 11 numbered items.  There are no absolutes in amplifier designs, just optimized designs based upon the designer's goals.  There are also no "new" circuits in tube amps and preamps, but the quality of passive parts has steadily improved.  Some current production tubes, not all or even most, are as good as the NOS from the 50s and 60s.

Wind Chaser

Re: Amplifier design: Truths or Myths?
« Reply #12 on: 28 Jul 2008, 11:35 pm »
As with all things, there is a bit of truth and some B.S. with each in the list below.

AND

I would say with all of these, its a matter of implementation, thus "generalized" statements are mostly untrue.

I'd say the above about sums it up.

6BQ5

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Re: Amplifier design: Truths or Myths?
« Reply #13 on: 28 Jul 2008, 11:56 pm »
Quote

Maybe so,,, maybe not. Are you welcoming other amp designers to freely post their design ideas & philosophies here? I don't know about that, do you? :D


I'm surprised that posting here has caused so much confusion. Given I use Music Reference gear and I respect Roger's opinions, I felt this was a good place to start for me.

It's also a free world (last I checked), so I'm all ears to hearing other opinions and ideas.

If I'm causing problems, I can also just shut-up I guess.

satfrat

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Re: Amplifier design: Truths or Myths?
« Reply #14 on: 29 Jul 2008, 12:03 am »
Quote

Maybe so,,, maybe not. Are you welcoming other amp designers to freely post their design ideas & philosophies here? I don't know about that, do you? :D


I'm surprised that posting here has caused so much confusion. Given I use Music Rerence gear and I respect Roger's opinions, I felt this was a good place to start for me.

It's also a free world (last I checked), so I'm all ears to hearing others opinions and ideas.



It wasn't my desire to cause you confusion, it was my desire to give you workable options so that you might just get your "educated" opinions from more variety of respectable amp designers . I'm sorry you can't follow that logic.  :thumb:


Cheers,
Robin


ps, I'll just add that you ask very good questions and I for one would like to hear from designers from many different types of amplifier designs on their thoughts, not just from 1 manufacturer and a bunch of opinionated audiophiles. But I'm afraid that's all that will result from your thread emplacement,,, that is if Roger will offer his thoughts to your questions.  :D

jules

Re: Amplifier design: Truths or Myths?
« Reply #15 on: 29 Jul 2008, 12:55 am »
Quote
I would say with all of these, its a matter of implementation, thus "generalized" statements are mostly untrue. However, what is the "real story" with these? They can't be entirely right or wrong either.

True!  ...  :D

You've answered you're own questions and other than that, there's far too much in there for any one post to answer in detail.

Take 12, on Chinese products though, just to look at one that others might not. I've used various Chinese products and the quality has been quite exceptional in all respects. Of more interest to me anyway, is the very different philosophical approach to design that can be seen in ideas like modular construction but that's a topic that could take up a page on its own. Also interesting, is the Chinese approach to intellectual property rights ...  :), which can lead to all sorts of interesting copies of great designs.  I'm sure there's Chinese junk out there as well.

jules


bpape

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Re: Amplifier design: Truths or Myths?
« Reply #16 on: 29 Jul 2008, 12:59 am »
Who the hell is Mark?  :scratch:   :wink:

Bryan

satfrat

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Re: Amplifier design: Truths or Myths?
« Reply #17 on: 29 Jul 2008, 01:01 am »
Who the hell is Mark?  :scratch:   :wink:

Bryan

Another good question,,,,, now please answer my PM!  :lol:

Ericus Rex

Re: Amplifier design: Truths or Myths?
« Reply #18 on: 29 Jul 2008, 11:59 am »
6BQ5, I think Robin has a good point.  Why not move this great post over to Audio Central and get a wider audience?  You could PM Roger,...and Mark(?), asking for his feedback on the topic.

woodsyi

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Re: Amplifier design: Truths or Myths?
« Reply #19 on: 29 Jul 2008, 12:29 pm »
6bq5,

Although they are not forbidden by rules to post anywhere outside of their own circle as long as their product or service (tricky interpretation here) is not mentioned,  I believe most feel that it's not courteous to post in other industry circles without a direct invitation from the circle owner.  So you would have more chance of getting someone from the industry to comment if this were in neutral circles like the Audio Central or Industry Talk.  IMHO, good topic. 
« Last Edit: 29 Jul 2008, 02:20 pm by woodsyi »