Folks speak of amps as if they are like speakers. It's only a hobby. Nothing critical or serious. So that's cool. No need for heated debate. We can peacefully disagree. That's cool. But........
We all can see how every single speaker measures differently. So yes, we can see why they would sound differently. Their on-axis and especially off-axis responses vary so greatly.
But all these amps measure almost exactly the same. Their frequency responses are identical. 20Hz-20kHz +/- 0.0dB or +/-0.1dB. Their distortions are like 0.01% or better. Their SNR are -110dB or better. Absolutely inaudible. There are also actual double-blinded studies where they perfectly level match the amps and people can't tell the difference.
Ah, yes, perfect level matching is paramount because amps will have different gain levels. Some are 34dB, 32dB, 30dB, 28dB, 26dB, 24dB, etc. Even a 0.5dB gain difference will tip the scale in favor of the higher gain amp.
People say, "But I did level match". How? By ear? Please! By their $50 SPL meter? Better than by ear, but still, please. These meters have a +/-2dB error margin/ tolerance or worse.
I suppose as a healthcare professional who sees clinical double-blinded drug studies all the time at my hospital, I tend to trust scientific and engineering methodology more than by ear or gut instincts. I realize that double-blinded amp studies will never carry the same weight as clinical drug studies on patients.
But these double-blinded amp studies with true precision level matching (instead of by ear or inaccurate SPL) with multiple test subjects do have merits.Edited by AcuDefTechGuy - 7/22/12 at 1:03pm