Bitmap Frogs said:
Blind test with matched outputs to the milivolt or bust, brother.
The brain plays tricks on us.
it could work both ways though, make distorted signals sound good as well, make cheaper equipment sound good in your mind. class A, A/B, D all work in different fashion, not to mention a less powerful amp will get saturated a lot earlier than a more powerful one. my 50 watt amp lost dynamics and used to shut off at high volumes, my 250 watt amp does music effortlessly. definitely not at all the same.
theoretically, an amp amplifies signals, true, but there are many designs. it would be presumptuous to think they would all sound the same. even in my electronics courses, perfect sinewave input signals were distorted to hell at the output of the feedback amps we used to build on bread boards. if you listened to it, it'd probably sound a lot closer to the input signal than it looked. yet, a better circuit yielding a closer approximation of the input signal would possibly sound even closer. basic circuit elements have +- tolerances to deal with, hence the closer to tolerance a device is made, ie, the more precise it is in regards to its ratings, the more expensive it is. because its harder to make it. that doesn't mean these materials have to be hand made, and cost 1000s...a good quality amp could probably very well be manufactured under $100 using off the shelf, but measured and carefully selected elements.
now better is a different issue, a lot of the times better signal isnt necessarily an accurate amplification. what sounds pleasing is subjective, and at the end of the day you guys have no talking points, even if you keep forcing the idea about psychoacoustics. what is the point if at the end of the day, the listener is more pleased with the new setup? what does it matter?
now, better power chords, usb cables and so forth, yes i would call BS on that. the power is being drawn from the outlet, through a passive conductor, and there should be no reason at all for a more expensive cable to make the power AC signal nicer for your equipment, by default its passive. if its doing anything to the signal, then its not a good cable to begin with.