I do not think this is possible. Listeners vary in preference, so if you compare two different amps, one group of listeners may prefer A, and the other group may prefer B. That is why some people swear by SE tube amps, others by non-complement class A, others by class AB, others by class D and others by super-high feedback balanced/complementary amplifiers.
Thus, you cannot find some kind of magic formula that says A is better than B.
jan didden
Sometimes audible effects are measurable by standard equipment, sometimes not.
With high-level system, effect of audiophile connectors and resistors are quite listenable, in high-freq and imagine domain, but hardly measurable, only with very special equipment.
THD distortions are easily measurable, but many find out, that they play almost no role in listening impressions (mainly system livliness), that are carefully estimated by audiophiles.
I do not agree. Many of these audible differences disappear once you limit your perception to your ears only. Those that do not disappear, can be measured.
jan didden
If everybody would agree with this statement, then would be better not to spend time at forums, with a hope to learn some findings, and to live with very good measuring mid-fi system. People pay for satisfying their personal sound requirements, and this can hardly be changed, by claiming that one can not listen that or this, since it is not catched by spectrum analyser. Is it pure subjectivism? Not pure, since effects of every not only active, but also passive part can be measured. If one decide not to care of these effects, then why should one convince others to stop their searches?
Jan,
If we define "audible" as caused by changes in sound, yes.
However we may percieve changes that do not effect anything audible, but alter our perception (and I am not talking about LSD either)...
Ciao T
If we define "audible" as caused by changes in sound, yes.
However we may percieve changes that do not effect anything audible, but alter our perception (and I am not talking about LSD either)...
Ciao T
Hi,
And if they do not disappear, we always can use statistical "magic" to make them disappear anyway...
An interesting exercise no longer possible (the data appears ton have been taken down to prevent a re-run of this test) was to actually take all the individual "null result" tests published by the ABX Mafia and to analyse the whole dataset to see if the full set of all the tests together would still produce a null result*...
Ciao T
* Hint, the data of all the tests analysed together suggested that in fact audible differences were present in at least a significant number of the test, however they where essentially made to disappear using statistical magic...
And if they do not disappear, we always can use statistical "magic" to make them disappear anyway...
An interesting exercise no longer possible (the data appears ton have been taken down to prevent a re-run of this test) was to actually take all the individual "null result" tests published by the ABX Mafia and to analyse the whole dataset to see if the full set of all the tests together would still produce a null result*...
Ciao T
* Hint, the data of all the tests analysed together suggested that in fact audible differences were present in at least a significant number of the test, however they where essentially made to disappear using statistical magic...
Yes, fully agree. In fact, I believe this happens almost 100% of the time. It is very, very difficult to shut off part of your perception apparatus and just let one go through, like the ears.
I bought a couple of MusicMasks. These look like ski goggles but are compeltely dark. The idea is that you can shut off the visual input without having to shut your eyes. To me, putting on the MusicMask or shutting my eyes both create a dark environment but still 'feels' different. For some reason, I can listen 'easier' with eyes open than with eyes shut. Maybe the concious decision to shut your eyes makes a difference, but I'm just speculating now.
jan didden
My 2 cents, and nothing really to add but, I spent sometime differentially comparing amp outputs in the time domain (in part because I don't have any form of frequency analyzer at home) mostly in the search of why my wife prefers a certain tube amp.
I've tried with amps driving "similar speakers" but of course they aren't identical. I've tried driving a single speaker with parallel amps through 2 ohms resistors but then of course you have 2 new ohms. I'm now looking at driving each coil of dual coil speaker (but of course this is loaded with problems, mostly there are a few additional questions I'm trying to understand for myself with this test). For these tests I monitor the current difference through a single current probe. I find that I spend most of the time trying to null out the common using a sinewave, then I'll sweep the sine, then I'll switch to music tracks and simply force my digital scope to trigger (over and over again at different time bases etc). So far any temporary discover doesn't pan out.
The leads that I am typically following for these amps anyway are not so much in the differences during complex waveforms (to within my measurements they match) but rather the occasional lower frequency difference following significant highs (but well below any clipping effects).
Basically in doing these I'm convinced I need a much more stable reference input (but my wife wont comment on which amp she prefers the chirp from)
In my particular case I don't believe I am searching for effects anywhere below the "equivelent" of 5% THD, but it has been fun and instructive.
edit: In case in didn't come across I've done more testing to show how flawed my test sets are than actual testing, i.e. I can see current difference in the same speaker types but no discernible voltage difference, etc
Thanks
-Antonio
I've tried with amps driving "similar speakers" but of course they aren't identical. I've tried driving a single speaker with parallel amps through 2 ohms resistors but then of course you have 2 new ohms. I'm now looking at driving each coil of dual coil speaker (but of course this is loaded with problems, mostly there are a few additional questions I'm trying to understand for myself with this test). For these tests I monitor the current difference through a single current probe. I find that I spend most of the time trying to null out the common using a sinewave, then I'll sweep the sine, then I'll switch to music tracks and simply force my digital scope to trigger (over and over again at different time bases etc). So far any temporary discover doesn't pan out.
The leads that I am typically following for these amps anyway are not so much in the differences during complex waveforms (to within my measurements they match) but rather the occasional lower frequency difference following significant highs (but well below any clipping effects).
Basically in doing these I'm convinced I need a much more stable reference input (but my wife wont comment on which amp she prefers the chirp from)
In my particular case I don't believe I am searching for effects anywhere below the "equivelent" of 5% THD, but it has been fun and instructive.
edit: In case in didn't come across I've done more testing to show how flawed my test sets are than actual testing, i.e. I can see current difference in the same speaker types but no discernible voltage difference, etc
Thanks
-Antonio
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2 magoman
Try simple Hafler test, put the same signal in two amps You want to compare (supposing both are not inverting or both are inverting). Conect "differential" speaker between live output terminals of both amps (both normaly loaded by resistive load) and balance gain of one amp to cancel difference in amplitude . Resulting sound is real time difference between amps, catching all aspect (in time and amplitude) in sound differencies, separated from signal.
And now connect other speaker normaly (live to GND) at one output instead resistive load and try disconnect/connect back "differential" speaker . Can You 100% sure hear difference in presence of normal music signal ??
Try simple Hafler test, put the same signal in two amps You want to compare (supposing both are not inverting or both are inverting). Conect "differential" speaker between live output terminals of both amps (both normaly loaded by resistive load) and balance gain of one amp to cancel difference in amplitude . Resulting sound is real time difference between amps, catching all aspect (in time and amplitude) in sound differencies, separated from signal.
And now connect other speaker normaly (live to GND) at one output instead resistive load and try disconnect/connect back "differential" speaker . Can You 100% sure hear difference in presence of normal music signal ??
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I think this a good test, but be aware that the remainder after cancellation is not necessarily some kind of shortcoming or distortion. Even small differences in phase shift versus frequency give audible outputs, but does not mean one amp is 'better' than the other.
The second part of the test can also be quite revealing, but not as most would like it.
jan didden
The second part of the test can also be quite revealing, but not as most would like it.
jan didden
I did that test on the original Hiraga 20W Class A maybe 25 years ago. The outcome was miserable. The Hiraga has high distortion and poor damping factor. Somehow it managed to sound very good under listening conditions so i was stuck. That is when Luigis second theorem comes into place. IT IS THE WHOLE CHAIN. Somehow the Hiraga was able to "repair" other flaws in the chain. I call that UNMASKING but i know this idea will not catch up. As long as we do not accept that parts of the chain are flawed the input = output philosophy will not be challenged.
Ed,
Don't tell them all the good secrets.
BTW, more fun, drive one channel, the other no input, connect your speaker between the positives. Check the output of the undriven channel. Connect a closed back headphone there...
Ciao T
Don't tell them all the good secrets.
BTW, more fun, drive one channel, the other no input, connect your speaker between the positives. Check the output of the undriven channel. Connect a closed back headphone there...
Ciao T
That is to me the Picasso or Rembrandt question. As we build better components at every stage the final result gets better. Adding color or increasing expression to a flawed system is a valid approach to reproducing the emotion of the music.
My OPINION is that one of the current giant obstacles is that everyone KNOWS our hearing is limited to 20 Hz to 20 KHz. When I play 30 KHz. tones people tell me they don't hear them, but then they can tell when it is turned off and back on!
Joachim,
It has high distortion, compared to what?
The Human Ear? (>> 30% THD at 92dB/200Hz)
A dynamic speaker? (>> 0.3% THD at 92dB/200Hz)
A piece of wire?
Also, damping factor is overrated, massively.
As long as the voice coils are not wound with room temperature and/or high temperature supra conductive wire there is not a krell of a lot of difference between damping factor 8 and damping factor 80000 in the speaker output, including step/impulse response.
This is one possibility.
I am seriously considering that in effect, the "additions" commissioned by Tube Amplifiers with High THD and by Non-Oversampling Multibit DAC's is what gives them their distinct quality, one that is often sought after by music lovers.
For if this was the case it would not be too hard to introduce these additions to more conventional and much lower cost designs, which has great commercial interest.
So far my experience has remained that this does not work.
Just adding 0.5% 2nd HD at -10dB of full power and 5% at full power, with otherwise similar patterns of HD and even the bandwidth limitations and rise of HD at LF does not render a solid state amp that sounds like a SE Tube Amp.
Ciao T
It has high distortion, compared to what?
The Human Ear? (>> 30% THD at 92dB/200Hz)
A dynamic speaker? (>> 0.3% THD at 92dB/200Hz)
A piece of wire?
Also, damping factor is overrated, massively.
As long as the voice coils are not wound with room temperature and/or high temperature supra conductive wire there is not a krell of a lot of difference between damping factor 8 and damping factor 80000 in the speaker output, including step/impulse response.
This is one possibility.
I am seriously considering that in effect, the "additions" commissioned by Tube Amplifiers with High THD and by Non-Oversampling Multibit DAC's is what gives them their distinct quality, one that is often sought after by music lovers.
For if this was the case it would not be too hard to introduce these additions to more conventional and much lower cost designs, which has great commercial interest.
So far my experience has remained that this does not work.
Just adding 0.5% 2nd HD at -10dB of full power and 5% at full power, with otherwise similar patterns of HD and even the bandwidth limitations and rise of HD at LF does not render a solid state amp that sounds like a SE Tube Amp.
Ciao T
I measured the FRD of 9 year old boys. They could hear up to 24kHz on a good headphone.
I manage 16kHz with a bit of cheaten. Still i trust the research of a Japanese that measured brain activity when he added tones over 20khz. Interesting was that it did not matter much if that tones where part of the music or just randomly created. Anyway, i think a CHAIN that goes to 20kHz is just fine. That is not the problem. SE, you are a genius but until that post i did not recognize it. I apologize.
I manage 16kHz with a bit of cheaten. Still i trust the research of a Japanese that measured brain activity when he added tones over 20khz. Interesting was that it did not matter much if that tones where part of the music or just randomly created. Anyway, i think a CHAIN that goes to 20kHz is just fine. That is not the problem. SE, you are a genius but until that post i did not recognize it. I apologize.
I don't think that two wrongs can make a right, as a general rule. Some speakers with freaky impedance curves may benefit from special cables that would be wrong for most other speakers, but this is about the only situation I can think of.
The safest bet is to take all the individual components in a chain and optimize those for maximum compatibility (flat FR, acceptable input/output impedances and voltages, etc), what Simon describes as 'stable subassemblies'.
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