I refreshingly straightforward and common sense approach.
As for blind ABX testing, for a start it's not what audiophiles (or hi-fi enthusiasts) typically do to evaluate equipment. So what? many will say. However after that, the more blind ABX is constrained to ensure the repeatability and legitimate scientific rigors, less like the real listening experience it is -- i.e. the test results are valid only under the specific conditions of the test and cannot be generalized to all circumstances.
I think you are confused. The ABX test is
the easy environment in which to distinguish one amp from another. If this test is failed it
defies common sense that there will be actual perceptible differences that will be discovered in everyday use. The latter presents profound obstacles to making any kind of comparison between audio gear that has similar performance specs.
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There are well established reasons for why you perceive that amps sound different. In almost all real world playback environments two amps will never sound exactly the same.
What people don't acknowledge is that the perceptual biases that cause us to hear audio differences when none truly exist is that they actually do make things sound different. The perception of difference is not an 'illusion' or an 'imagined perception' it is a real, actual perceptual difference.
Even playing back the exact same passage on the exact same system will lead to different perceptions of sound. Our minds are constantly adjusting our perception and focus.
Couple this with the many objective reasons why comparing two amps in the real-world will lead to the conclusion that they sound different:
- Unless the amps have some kind of super calibrated gain structure, playbacks levels between amps will be actually different
- the problem of level matching is compounded by the different gain structures and resolution of the volume knobs.
- one amp might not be operating to spec
- tube amps or vintage amps can have a non-flat frequency response
- if tone controls are available on either amp, this can seriously compound efforts to understand how the amp sounds.
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This discussion is the 'vampire debate' of audio and it's about as settled as anything can be that competently designed amps are sonically in-distinguishable
under specified conditions. This has been proved over and over with ABX testing.
To decide whether the results of such ABX testing are meaningful to us, potential user of an amplifier, requires interpretation and an analysis of how
the conditions for these ABX tests relate to 'real-world' listening concerns.
Richard Clark ran a relatively famous $10k challenge for anyone who can distinguish two amps in a blind ABX test. Nobody ever claimed the prize after 100s of iterations. (If you've never read about this, it is truly a fascinating experiment worth learning about
https://www.stevemeadedesigns.com/board/topic/193850-richard-clark-10000-amplifier-challenge/)
He had some strict conditions (strict in the sense that they must be met, not that they imposed unrealistic expectations on the amps or listeners)
- amps must be commercially available from reputable companies
- amps must be working (functioning at spec)
- test is performed on dynamic speakers (as opposed to something like an electrostatic design)
- amps level must be kept under either clipping or 2% THD 20Hz to 10kHz
- must be level matched to .05 db (on both speakers)
- absolute polarity and L/R are consistent between amps
- if the amps have a different frequency response then one must have some EQ applied to make them the same
- amplifiers must be brand name, standard production, linear voltage amplifiers
- program material must be commercially released music
Within these constraints are a wide range of possibilities and parameters under which the test could be conducted!
Contenders could:
- pick any two amps to compare (including car amps, tube amps)
- use any speakers
- use any music
- control the level of the playback
- can take as long as they want and switch between amp A and B as many times as they want
- if EQ is applied to equalize frequency response they can pick which amp gets the EQ
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The question for a potential user of an amp is: do the conditions and results of a test like the Richard Clark $10k Amp Challenge provide meaningful guidance on the selection of an amp suitable for purpose?
I argue that this provides a ton of useful, practical information for a consumer. It eliminates the worry about aspects of amp performance that are very difficult to impossible to evaluate in normal listening environment.