I'd gladly invite anyone to my place for a listening session to disprove to me that there is no sonic changes even just between my Rotel RSX 1065 and my Bryston 4B. If they can not hear any diffrence I would gladly accept that my ears and brain is lying to me and that I am going crazy.
As with the findings 2X6spds has found (non scientific or non electrical) I would agree with him. I too have heard sonic differences with different amps.
Also I read it everywhere in articles, magazines and books for the last 2 decades. To me that good enough as fact.
If I never took advice from articles and forum posts and thought it was all crap then all that reviews from the "experts" are all bogus crap too.
I use my ears and it is a good enough tool to tell me if the sound is better TO ME or not. If your telling me that a Krell or Mark Levinson is as good as your Denon, Pioneer, Yammys I'd like to know what crack your on. If those same livingrooms had the chance to audition some of those high end audio pieces then I would take your word for it. If not all you are regurgitating is someone elses diction. I have had the liberty to demo some nice equipement in MY livingroom. And we are not talking between same monetary range amps, like budget separate amps vs new surround recievers with ample wattage. I'm talking about audio gear such as a Krell KAV 300 Integrated vs a Denon amp/receiver.
Put away your p*nis analysers, get off your god complex and open your ears.

Amps that made my livingroom:

Bryston 4B
Bryston 3B
Bryston 2B
Krell KAV 300 Integrated
Rotel RSX1065
Rotel RSX1055
Onkyo Integra DTR 5.1
NAD 752
NAD early model integrated
HK AVR225
HK AVR10
Denon early model AC3 ready receiver
Rotel early model integrated stereo

ps: Just to add more lighter fluid to the fire. I still love and stand by my KIBERS! All those pretty colors. Just as good as pork fat.