I still think it is genuinely possible for amps to make a difference in sound quality. I think it has more to do with the ability to play without distortion or tonal shift as spl increases. As for frequency response, both these amplifiers measure the same so far as the graphs show at a pink noise output of 75db.
There would have to be a technical difference for amps to sound difference such as SPL out of the range of the amp specs (e.g. distortion) or a specific reason why some limitation was applied to an amp that may change the sound (e.g. some kind of filter or super thin internal wiring, etc.).
Otherwise within specs, all amps should be designed to produce the most accurate sound which is to say in a frequency sweep the amp produces nothing but a ruler flat line.
This is most common in virtually any measurement i've seen from competent SS amp builders.
I have a friend who for the longest time was a stereophile. Collects vintage gear for decades now and knows his electronics specs! Was always a stalwart believer in amps sounding different until his guru electronics friend built an instantaneous switcher and they did some playing around with different amps in A/B testing.
Now admittedly
if there are differences between amps, they are so small that they are virtually unnoticeable. SPL still needs to be applied which their switcher does not do, and as such, by eliminating that last piece of the variables, the nonconvertible may have been converted simply by doing a more controlled test.
Is the magic gone?
Maybe a little.
But they still like the bling and being able to crank up a 500W /ch amp to its max!
There's always still fun to be had.
