Actually my original point was: even experienced listeners couldn't differentiate what I have assumed as obvious. In a blind test, it is way harder, while in actual listening, it is hard to believe that 3-stage high distortion tube amp can sound similar to for example complex low distortion solid state amplifier.
So the point is: conscious skill is way worse than sub conscious skill. If people cannot hear the difference between amplifiers in a blind test, it doesn't mean that it is better to use chip amps because it is cheap and easy. Because in the long run you can "feel" it.
I have given an analogy about using certain brand of mineral water for daily consumption. I believe that only a few people can differentiate it blindfold (I could). But we can do the following experiment:
Use brand A, and watch the average consumption after a few months. Repeat for brand B. Then let Statistics work. The idea is, when the water doesn't taste well, we cannot drink more and then that bad experience will make us reluctant to consume more for the next time.
If you are not sensitive to difference, try it. Because I believe that this applies to everyone, sensitive or not.
I am referring to thd, only]
Thx-Dick Marsh
-140 dB THD at 7V into 50 ohm is no problem at all.
-140 dB THD+N is a slight problem, but it can be done.
BTW: You have to make a complete spec. if you want someone to design such a thing.
Cheers
S
That's why I ask you to try the water experiment. It is to prove that it applies to YOU. Not to ME because I can prove my sensitivity. With my current mineral water, I cannot drink more than a half glass. Blind testing several brands, yes I have. So again, it is not about me.
Same with the audio. My concern is that even if John Doe cannot differentiate between $50 amp A and $5000 amp B in a blind test, it doesn't mean that he will equally enjoy both amps (not psychologically).
This is also the reason why I often mention about enjoyment, about how often/long we listen to our system in a day or week or month. It is a function of enjoyment, not just spare time.
As for me, I believe I can differentiate the X and Y samples posted by Mooly easily in Foobar. But what for??? I don't need to prove anything to myself.
Appreciate the correction.
Certainly, if you're determined not to do it. And especially if you have a financial and personal stake in the outcome.
A poorly designed experiment to answer an unspecified question that I don't really care about. Right, I'll get on it immediately.
There is some truth in that (within limits): properly made tests on properly large samples of individuals tend to show that people always tend to prefer "better reproduction systems", ie having a flat frequency response, good linearity, good SNR, absence of non-harmonic artifacts, etc.
Such fine tendencies only appear for very large sample sizes, and are generally obscured in smaller tests, but they are a reality, and they are the foundation of the psycho-acoustics corpus of knowledge on which all "modern" designers rely, even the one that reject blind tests, objectivism, etc, on the basis that human earing (theirs in particular) is much superior; which might be true, after all, but in the end what counts are not exceptions but mainstream tendencies.
In an another field of perception, trichromic reproduction has ended achieving a good level of accuracy and sophistication for most of us, but there again, it is essentially due to painstaking efforts of people processing large amounts of statistical information and doing their homework. That said, this relatively evolved color reproduction technique is a bit weak for some (gals, not guys) having a quadrichromic gene.
Not everybody is born equal, but if recording, reproduction and compression systems are tailored for the masses, there is little point trying to improve a minuscule and insignificant step in that system... Too bad for golden ears...
Nevertheless, Scott's point is well taken: using an op amp specified for 600 Ohms with a 100 Ohm resistor boils down to testing the endurance of just that one op amp and nothing else. People, this is not 5 or 10% less than the minimum load, this is 1/6 of the minimum load.
John, how would you react if somebody started tresting your amps by loading them with 1/6 of their nominal load? If you specified 8 Ohms, with 1.33 Ohms? No amp that I know of, even the exalted ones, would smile at that, at best it would switch itself off upon overheating, or its overcurrent limiters would fire.
But most of all, I believe this is a totally pointless exercise altogether. 99% of all op amps will fail this test, or would work but at significantly reduced output level, which may or may not be a problem depending on what you expect from it.
What I find silly in all of this is the underlying logic - I want lots of current, so I'll sit down and test 'em all to find one which just may do the trick AND sound decent to boot.
If I was into this, I'd never go for an op amp which might satisfy my requirements but with silly trade-offs, I'd go for an op amp which sounds good all on its own and then I'd add a dicrete current booster. This would not only not introduce more distortion, it would in fact improve the distortion figures beyond anything an op amp on its own could do. In other words, I wouldn't go searching for an op amp which might do what I want it to do without too much distortion, which puts me in the role of serving the op amp, instead I'd make the op amp serve me.
You want amps from an op amp? No problem, just add a pair of drivers and get them to drive 2SC5200/2SA1943 trannies (cheap, available everywhere) and you're talking about impulse currents of over 10A. That would, of course, fry both the phones and your head, but hey, you got there with a bang.
Did you all forget that there is about a ton of schematics on the web of amps which use op amps for their input stage. In fact, some companies thrived on it, for example BGW, even way then when the choice was WAY smaller than today.
John, how would you react if somebody started tresting your amps by loading them with 1/6 of their nominal load? If you specified 8 Ohms, with 1.33 Ohms? No amp that I know of, even the exalted ones, would smile at that, at best it would switch itself off upon overheating, or its overcurrent limiters would fire.
But most of all, I believe this is a totally pointless exercise altogether. 99% of all op amps will fail this test, or would work but at significantly reduced output level, which may or may not be a problem depending on what you expect from it.
What I find silly in all of this is the underlying logic - I want lots of current, so I'll sit down and test 'em all to find one which just may do the trick AND sound decent to boot.
If I was into this, I'd never go for an op amp which might satisfy my requirements but with silly trade-offs, I'd go for an op amp which sounds good all on its own and then I'd add a dicrete current booster. This would not only not introduce more distortion, it would in fact improve the distortion figures beyond anything an op amp on its own could do. In other words, I wouldn't go searching for an op amp which might do what I want it to do without too much distortion, which puts me in the role of serving the op amp, instead I'd make the op amp serve me.
You want amps from an op amp? No problem, just add a pair of drivers and get them to drive 2SC5200/2SA1943 trannies (cheap, available everywhere) and you're talking about impulse currents of over 10A. That would, of course, fry both the phones and your head, but hey, you got there with a bang.
Did you all forget that there is about a ton of schematics on the web of amps which use op amps for their input stage. In fact, some companies thrived on it, for example BGW, even way then when the choice was WAY smaller than today.
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Cool, I'm not surprised if it is true.
Jan Didden has mentioned somewhere a few days ago, regarding what gives the "subjectivists" a bad name. The point is, it is often true that there is audible differences, it is the claim that someone hear a difference that might not be true.
But some people have unique characters. Instead of finding the truth about the topic, they find the truth about people character, and become prejudice
Why, I tend to think that everyone is the same, or have the same "requirements" when it comes to music (only different thresholds).
What is a golden ear, anyway? My ears are so sensitive. Not to goodness, but to badness. So I know very well when I'm in pain!
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