Another newbie question, albeit a slightly nuanced one :)

[Chrispy]

Such wonderful descriptions of users emotion in using three different amps. Fascinating.

 

[Cbdb2]

Sorry I’m not sure I even know what that means so I’m probably not doing that

If there's more than a few seconds between swapping amps your memory will deceive you. Audio blind test switching (especially if theres little difference ) should be instant.

 

[DVDdoug]

There's evidence that two identical amplifiers will sound different if one is even 0.1% louder than the other (we all prefer the louder amplifier).

Possibly - I'm not sure I can hear a 1dB difference (about a 20% power/wattage difference) with regular music/program material which is changing moment-to-moment. But the idea is to eliminate loudness as a variable. Even if it doesn't sound "better" there should be no "clues" in a proper blind listening test so you can't fool yourself (or anybody else).

If there's more than a few seconds between swapping amps your memory will deceive you. Audio blind test switching (especially if theres little difference ) should be instant.

Maybe, but in the real world you're not going to switch amps instantly. It is a better way to "prove" that you're hearing a difference* but in in the real world if you can't hear a difference between Monday and Tuesday it's not worth switching equipment.


* An ABX Test doesn't prove anything. It gives you a statistical result, so you can say something like, "there is only a 0.1% chance that the participant was guessing."

 

[MaxwellsEq]

I'm not sure I can hear a 1dB difference (about a 20% power/wattage difference) with regular music/program material which is changing moment-to-moment

That's exactly the point! You can NOT hear a difference this small, but your brain prefers the louder one.

This links to a Bob Carver article from 1973 where there is a throwaway observation:

When we were finally able to get the output levels of the two power amplifiers exactly matched, there was absolutely no audible difference when switching between them while listening to either white noise or music. During the adjustments of the amplifiers, it was demonstrated dramatically that minute differences in volume level (sound quantity) that are too subtle to be heard as such are interpreted by the ear as "obvious" differences in sound quality. Everyone was startled by the effect — everyone, that is, except Larry Klein, who had touched upon the phenomenon some time ago in his Audio Questions and Answers column