Do all audio amplifiers really sound the same???

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#542
Magura said:



An interesting fact is though, that very many people actually likes some distortion component.
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This is a good point, and something I've been thinking about since reading the Stereophile article I posted in #523. Although all audio nuts are interested in sound, and things that change sound, it seems some people (reviewer types) are trying to make aesthetic value judgments. Engineer types are trying to qualify performance differences. The goals are not the same, and it is no wonder that one doubts the methods and results of the other.

The thing is they are not mutually exclusive, and if anyone is interested in learning/growing/progressing in their ability to hear/build equipment, they would do well to learn how to appreciate the importance of either method.
 
#543
Bratislav said:
This is going nowhere.

<snip>
Did Peter Walker rig his test ? Or were Golden Eared Ones from few decades ago much more deaf than GEO's of today ? Beats me. All I know is that balooned egos of local HiFi snobs get invariably deflated to the size of peanut whenever they can't see which amp is playing. "Peer pressure" I hear you crying. Well, you know what - you are right ! "Hic Rhodos, hic salta!" is all you will hear from me, every time, all the time.
Maybe we just don't cultivate our share of proper GEO's in my neck of the woods ? Maybe is the water ? Hmmm ...
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Ummm... back in the day there was no need to "rig" anything, as the quality of the source material was generally reasonably poor, eh? It is only in the last decade (approximately) that most people have access to source material that is fairly close in quality to the original "masters" of the era of "tape masters." Or one step above that, the original sound off a live mic...

The question folks is not if some people are of the ballooned ego variety - no matter the point of view taken - it is IF differences are audible, nothing more.

As far as "ALL AMPLIFIERS" - please read back in the thread, it's a shorthand for a more complex statement often made by the "objectivists."

Get the issues and terms right, before debating them?? :spin:

_-_-bear :Pawprint:

- join the :worship: REALISTS :worship: now!




ERGO SUM GOTO
 
#544
Recipe for constructing 2 amplifiers that sound different

xiphmont said:


Case in point: digital sample jitter. No one 'in the know' believed that was audbile either until an individual demonstrated he could clearly hear the difference in an A/B/X test. And that's all it took. The researchers and engineers immediately said 'well, *dang*!' and went to work understanding it, measuring it and fixing it. It only took evidence.
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So take any amplifier that meets the desired parameters (THD <0.1%, freq. response deviation from flat 20Hz - 20kHz <.01 db) and put a AD/DA conversion in front of it. The conversion surely can be made good enough so that the combination (AD/DA + original amplifier) still meets the criteria. Use a low jitter clock for one combination and call the combination amplifier A. Use a jittery clock for the conversion process and call the combination amplifier B (Of course don't put so much jitter that the criteria will be violated). According to what you have said there will be an audible difference between amplifier A and B inspite of both meeting the proposed "audio-equality" criteria.
 
#545
as the quality of the source material was generally reasonably poor
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I've got a bunch of records from the '50s that sound marvelous. And Walker may have used master tapes, which would presumably have been even better. There were great mikes and great recording setups being run then, all tube. Tube cutters, too. Nope, I can't accept that PW used poor source material.

FWIW, the most realistic demo I've ever heard was a direct-cut 78 (vintage similar to mine!) of Louie Bellson played on a Weathers FM cartridge/wooden arm combo (ditto). Astonishing. If it had only been stereo...
 
#547
Re: Recipe for constructing 2 amplifiers that sound different

cubex said:
Originally posted by xiphmont
Case in point: digital sample jitter. No one 'in the know' believed that was audbile either until an individual demonstrated he could clearly hear the difference in an A/B/X test. And that's all it took. The researchers and engineers immediately said 'well, *dang*!' and went to work understanding it, measuring it and fixing it. It only took evidence.[snip]
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xiphmont,

Would you by chance have any reference to that test? I'm quite interesting in such studies.

Thanks,

Jan Didden
 
#548
scott wurcer said:


The wine business has a group that runs away from DBT as fast as anyone.
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I know why-

My brother is a publisher and in this function he has been invited
to an anniversary of a buddy publishing company that has one of
those glossy magazines like "Gormandizing & Drinking" and one of
the top acts of the evening was a _blind_ test where the participants
had to know/guess the provenience of some wine specimens.

The thrill was that some of the wine-tasting point-allocating gods
were present and they had to compete. The gods lost big time.
My brother has a nice silver cup... :drink:

regards, Gerhard

p.s. I suppose most people would expect double blind tests to be
carefully executed if they had to take pharmaceuticals that could
blast their liver or heart.
 
#549
bear said:



Ummm... back in the day there was no need to "rig" anything, as the quality of the source material was generally reasonably poor, eh? It is only in the last decade (approximately) that most people have access to source material that is fairly close in quality to the original "masters" of the era of "tape masters." Or one step above that, the original sound off a live mic...
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The point here is not whether quality source was available in days of the 'experiment' (it definitely DID - some of very old recordings are still excellent sounding. Try Dorati's recodings with LSO in 50's). Walker himself owned a high quality studio tape recorder.
The point here is not that 405 or whatever was a 'perfect' amplifier.
The point is not even whether Walker made good amps or not (he did, BTW, IMHO).

The point is that audiphile elite of the day, back then, heard "vast differences" (just like in this thread) among the amps. And point is, those differences vanished when Walker level matched his amplifiers and made sure no clipping occured. I don't know how many samples were taken, or whether methodology was sufficiently strict to be accepted as scientific. All I know is that those "obvious" differences should have resulted in 100% hit rate. And they did not.

Not by a log shot.
 
#551
A nice setup is a delicate finetuned affair, music listening takes concentration...every time other persons are present I feel dissrupted and without the needed concentration...I can only enjoy music when I am on my own...and a DBT with lots of people present and lots of messing around...well, too much dissturbense to make any sense of anything and you may just as well use a "ghettoblaster" :dead: but ofcourse I can only speak fore myself

Just because you can easily trick and fool the brain doesnt mean that it can never be trusted...if you never trust your senses and intuition you have lost something very important in this life

If what I hear is due to placebo effect and imagination, so be it...at least it sounds nice to me :clown:

btw, could it just as well be placebo effect and imagination when you dont hear any differense, wanting it to be that way...who is "the kidder" 😉
 
#552
Robert F said:
It is interesting that the Quad 405 is used an example of progress or perhaps as an example of an essentially blameless component.

However those amongst us who have carefully and systematically
endeavoured to optimise he sound of our components will probably attest that it is a trivial matter to improve the sound of this amplifier as well as quite a few others, with a few well chosen substitute components or changes to wiring and lay out, the addition of snubber circuits and the like..
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Rob,

you're missing the point. Noone said 405 was perfect. Heck, show me one amplifier (or anything else for that matter) that can't be improved. 405 was built to a price by not even best available technology at the time. But that is not the point - point is, it could not be distinguished as 'lesser', 'poorer' or even 'better' sounding amp in blind listening tests.
You can definitely improve one or another aspect of the poor 405 (and all that will be easily measurable). The crux of the matter is - can you really improve its sound ?
 
#553
The only real valid test would be to take amp A and B and see how much good sound can be exstracted from both amps using any number of different speakers and sources...I am sure one would shine over the other

btw, what have been proved by testing 2 "similar" amps...even if proved "the same" you do very well know that there are other amps out there that are different...what would be the point ?

Another point...I dont suppose "the same" people will take part of the DBT
And I suppose that to give "the different" people a chance to hear any differense the 2 amps will be selected from "different sounding amps", or... :clown:

:scratch:
 
#556
Originally posted by Robert F
To choose but one example any amplifier using capacitor input power supplies will, not might, produce high frequency switching noise as the rectifier diodes go in and out of conduction.
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Not 'any'--there are amplifiers that damp that ringing with RC snubbers. There's a PDF at hagtech.com showing how to calculate the optimum values. Moreover, it's simply not an issue with tube rectifiers. So your generalization is plain wrong.

Originally posted by jacco vermeulen
steal some Black Pearls from Remy-M.
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Never tried that, RM's X.O at least is quite horrid compared to the similarly priced Hennessy and Delamain offerings, and so I wouldn't risk spending money on their more expensive stuff.

Originally posted by bear
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Speaking of recordings, perhaps the reason why some distortion may be considered euphonic is not intrinsic to the distortion but to what that distortion may be masking, such as other, harsher distortions in the recording chain, or jitter in the DAC, etc.

Originally posted by tinitus
If what I hear is due to placebo effect and imagination, so be it...at least it sounds nice to me :clown:
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But the insistence that one hears a difference when it's just a placebo is a disservice to others that are getting into audio, because they're more likely to buy into the religion and waste their money on things that really make no difference. The only safe personal opinion that doesn't affect society in the least is the one not expressed publicly.

btw, could it just as well be placebo effect and imagination when you dont hear any differense, wanting it to be that way...who is "the kidder" 😉
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The two opposing propositions are not of equal standing for the obvious reason that the combination of measurements, otoneurology, and psychology supports only one of them.
 
#559
That it nonsense, because it does not fit reality, any more than all autos of a certain size are essentially the same. Remember the Mercury vs Mercedes commercial? How well would you do, if you were blindfolded and put into the back seat of two similar size cars? Think you could tell much difference, if other factors were controlled as well? It is the same with amps.
I have spent a lifetime making amps from 5W to 2000W. None has sounded the same and the commercial and professional units that I used for sound reinforcement sounded different as well. Can I be fooled? Of course, give me an ABX double blind test with marginal speakers, marginal CD sources, lousy switchbox, etc. . Then I can't even tell a tubed Dyna preamp from a JC-2 of my own design. I know, because I did the test, myself in 1978, yes 30 years ago, and I reported it in the literature at the time. Unfortunately, the sonic differences immediately sprung back when I went back to long term listening, except that my girlfriend (future 'Absolute Sound' reviewer) said that she hated the sound of the switchbox itself, and that we should not continue to listen through it. THAT is another challenge! Why?
 
#560
john curl said:
How well would you do, if you were blindfolded and put into the back seat of two similar size cars? Think you could tell much difference, if other factors were controlled as well? It is the same with amps.
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I'm sorry Mr Curl, but it's not even close to being the same. You don't need eyes to hear but vision is a primary component in identifying cars, so your analogy is unacceptable.
Now, that poor quality components elsewhere in the system may mask fine differences could be possible, but that doesn't say anything about whether a test should be blind or not. There can be valid criticisms against specifics of how tests are conducted, but you cannot rationally attack the validity of the concept that a test should be blind. Time and again in countless psychological experiments covering all human senses it has been shown that bias and expectations have effect with power on our perception easily of the same order of magnitude as the actual stimulus, and so must be eliminated in testing--or else the often that what is being tested is but one's ability to fool oneself.
 
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