The first error is "I cannot hear the difference therefore you cannot hear it." Error of generalization and wrong.
Second is PMA points out no two different amplifiers every measure the same therefore the conclusion that the amplifiers are different must be true.
Third is where amplifiers really show their differences is in dynamic situations with constantly changing signals driving bad speaker loads as always found in music listening. Testing with a sine wave will never show these differences.
One of the main reasons amplifier design is not more settled is different designers decide different test have a higher priority of importance. As example I don't concern myself with THD if that number is less than 0.1% or in the noise floor at smaller signals. Some other designer may aim for 0.005% and chase that goal. Some designers want very high slew rates. I do not care so long as full power bandwidth is more than 25kHz. I mean where are these signals coming from that test the slew rate of the amp? Not from CDs or vinyl disc, both with sharp cutoff above 20kHz which could never induce slew limiting. And yet another designer decides small signal bandwidth is the goal and aims for designs which are -3dB at 1MHz. Well, that is the designers goal.
The result is many amps that sound very different.
As for hearing the difference some just do not. I was challenged one time to show I could hear the difference between several amps. The speakers were in one room and the amps in another where I could not see them at all. I successfully named 5 different amplifiers in 25 consecutive test where I could not see the amps or the person changing the amps. I just heard the sound when the signal was played. Level was adjusted in the separate room carefully with a DVM and test tone without the speaker connected. I never missed one. To me the amps were as different as blue and red. To a color blind person it is difficult to discuss subtle colors. To a tonality deaf person it is difficult to discuss timbre and character of sound.
For those of you who do not hear any differences feel blessed because the $100 amp will be just as good for you as the $100,000 dollar amp therefore it allows you to spend your hard earned on more content and less on hardware!!😀
Second is PMA points out no two different amplifiers every measure the same therefore the conclusion that the amplifiers are different must be true.
Third is where amplifiers really show their differences is in dynamic situations with constantly changing signals driving bad speaker loads as always found in music listening. Testing with a sine wave will never show these differences.
One of the main reasons amplifier design is not more settled is different designers decide different test have a higher priority of importance. As example I don't concern myself with THD if that number is less than 0.1% or in the noise floor at smaller signals. Some other designer may aim for 0.005% and chase that goal. Some designers want very high slew rates. I do not care so long as full power bandwidth is more than 25kHz. I mean where are these signals coming from that test the slew rate of the amp? Not from CDs or vinyl disc, both with sharp cutoff above 20kHz which could never induce slew limiting. And yet another designer decides small signal bandwidth is the goal and aims for designs which are -3dB at 1MHz. Well, that is the designers goal.
The result is many amps that sound very different.
As for hearing the difference some just do not. I was challenged one time to show I could hear the difference between several amps. The speakers were in one room and the amps in another where I could not see them at all. I successfully named 5 different amplifiers in 25 consecutive test where I could not see the amps or the person changing the amps. I just heard the sound when the signal was played. Level was adjusted in the separate room carefully with a DVM and test tone without the speaker connected. I never missed one. To me the amps were as different as blue and red. To a color blind person it is difficult to discuss subtle colors. To a tonality deaf person it is difficult to discuss timbre and character of sound.
For those of you who do not hear any differences feel blessed because the $100 amp will be just as good for you as the $100,000 dollar amp therefore it allows you to spend your hard earned on more content and less on hardware!!😀
For what? Aczel was not referring to a specific experiment, he was stating a fact about ALL reported controlled listening experiments to demonstrate amplifier audibility. The factors which have been consistently spotted in controlled listening tests are level, frequency response, high distortion, clipping, recovery, noise, and instability. Aczel qualified most of these in his statement. Are there any that he missed that have been verified in controlled subjective testing?
My question - and it has been stated before - is what measurements? Are we talking a simple swept sine 20-20K and the resulting FR? 1Khz @ 1W for THD? Into a purely resistive load? It would seem that's what Aczel is talking about, but I don't know.
There is much more to measuring amps than that. Please have a look at the work of Matti Otala from the 1970's regarding harmonic structure in amplifier distortion. There is good work before and after this, too in several countries. Then there is thermal distortion, transitory distortion, IMD, etc.
So what are Aczel's parameters?
There is much more to measuring amps than that. Please have a look at the work of Matti Otala from the 1970's regarding harmonic structure in amplifier distortion. There is good work before and after this, too in several countries. Then there is thermal distortion, transitory distortion, IMD, etc.
So what are Aczel's parameters?
"For those of you who do not hear any differences feel blessed because the $100 amp will be just as good for you as the $100,000 dollar amp therefore it allows you to spend your hard earned on more content and less on hardware!!"
+1
And the eternal battle between the Golden Ear Audiophile and the Tin Ear MeterReader goes on.....and on............and on..................
Golden Ear Audiophile hit with a brick "Oww, that
hurts! I'm bleeding!"
Tin Ear Meter Reader hit with a brick "You can't prove
I was hit with a brick! We need to do a double blind
ABX test!"
+1
And the eternal battle between the Golden Ear Audiophile and the Tin Ear MeterReader goes on.....and on............and on..................
Golden Ear Audiophile hit with a brick "Oww, that
hurts! I'm bleeding!"
Tin Ear Meter Reader hit with a brick "You can't prove
I was hit with a brick! We need to do a double blind
ABX test!"
I've changed 20 caps (output amp section) in my Technics ST-G90 to Rubycon ZL (same values of course) - very detailed & bright sound. Then I changed from Rubycon to Panasonic FC and all went smooth then I changed to Nichicon Fine Gold and all went dark and muddy. Same specs, same tuner, the HF & RF section completely untouched. Still VERY different in terms of tonality, stage & speed. Oh, I forgot... it's all imagination of course🙄
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Well you do have to be careful. Imagination is powerful and plays a big part. Ditto expectations. That's what the tests are meant to eliminate.
My 160W Leach amplifier would make 8" two-way speakers (B&W DM3000 and similar) distort. Other much larger (400W) amplifiers did not do this.
After modifying (bypass caps) a 120W McIntosh amplifier, it also made the speakers distort.
Removing the speaker grill we were able to see the soft vinyl dust-cap on the woofer was actually caving in on hard transients on the amplifier with the bypass caps. Peak metering showed we were no where near clipping.
After modifying (bypass caps) a 120W McIntosh amplifier, it also made the speakers distort.
Removing the speaker grill we were able to see the soft vinyl dust-cap on the woofer was actually caving in on hard transients on the amplifier with the bypass caps. Peak metering showed we were no where near clipping.
Opinion is a conjecture, falsifiable or not depending on its content. "In my opinion the rope suspending SY over the edge of the building will hold" is very much falsifiable. Another might be conjecturing without evidence why this post, which breaks so many of the forums rules, is nonetheless allowed to stand.
As generally used in the English language 'fact' describes a statement already considered true. It doesn't typically describe a statement that could still be proven false, subduing the 'falsifiable' aspect if not rendering it moot; in other words falsifiable in principle but almost inconceivable in practice.
So in my opinion, your split between opinion and fact in this context is more an expression of belief in the specifics (and a rhetorical device) than anything universally applicable
We must not let ourselves get fooled by the hype too. A really ugly looking diy amp could be as good or better than a flashy expensive commersial one.
Someone mentioned mono, for obvous reasons I play in mono during testing, when it's done I make channel2, usually later its fun to experience stereo,gets better. And about distortion why aim for nothing else than perfection?,but of course in real life there will be compromises and how thoose are implemented is the interresting part, it might get reduced to a single transitor and a lamp,or get very very complicated.. ;-).I will not deny people dealing with electronic design for a long time gets a feeling of how a circuit works that's at least equally important as the theroretical answer. What was this about again, I was just letting my mind go here, hmm well I join the people that think amps sound different. But with that said I can enjoy listening to music in my cheap computer speakers, main focus is music, I love music.
Someone mentioned mono, for obvous reasons I play in mono during testing, when it's done I make channel2, usually later its fun to experience stereo,gets better. And about distortion why aim for nothing else than perfection?,but of course in real life there will be compromises and how thoose are implemented is the interresting part, it might get reduced to a single transitor and a lamp,or get very very complicated.. ;-).I will not deny people dealing with electronic design for a long time gets a feeling of how a circuit works that's at least equally important as the theroretical answer. What was this about again, I was just letting my mind go here, hmm well I join the people that think amps sound different. But with that said I can enjoy listening to music in my cheap computer speakers, main focus is music, I love music.
The brain adjusts the whole thing..so...to evaluate you should not let this happens
switching fast from one to other..if you let it playing, the ear plus brain corrects everything.
Have you talked at the cell phone with the woman you love..and you were in a noisy environment?...noise was cancelled and you heard your woman.... why?... brain adjusts.
Listening computer speakers 3 minutes..you will start to listen bass..when there's no bass....brain feel the gap using musical memory.
regards,
Carlos
switching fast from one to other..if you let it playing, the ear plus brain corrects everything.
Have you talked at the cell phone with the woman you love..and you were in a noisy environment?...noise was cancelled and you heard your woman.... why?... brain adjusts.
Listening computer speakers 3 minutes..you will start to listen bass..when there's no bass....brain feel the gap using musical memory.
regards,
Carlos
rdf:
Opinion = "John Tesh is the greatest musician of all time."
Prediction = "If I hang John Tesh over the side of a tall building with a rope and let him go, he'll fall to his death."
Fact = I would be the hero of every music critic, living or dead.
Opinion = "John Tesh is the greatest musician of all time."
Prediction = "If I hang John Tesh over the side of a tall building with a rope and let him go, he'll fall to his death."
Fact = I would be the hero of every music critic, living or dead.
Aczel is a big fan of the "Power Cube" test and so am I. Really separates the amps that can drive a bad load from the many that cannot. A good starting point to use before any listening test. Good on the bench...then listen. Bad on the bench...try again. Bad means showing poorly on the power cube test. Listening to amps that test very badly and liking them simply proves you like bad sounding amps and not that the amp is good. Both kinds of test are required.
I really do not hope so for you, ML is pure rip-off, WIMA caps (aaargh) and Mexican resistors...
Once we made a blind test: Krell seperates versus Creek integrated or 20.000 dollars vs. 1000 dollars and guess what: 7 people (3 of them professionals) could not hear the slightest difference! But... the 2 amps measured extremely different!!!
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