What contributes most to a change in how an amplifier sounds?

@atmasphere ,

Thanks for making me feel stupid...

@atmasphere 

It all sounds amazing.  It's so complicated.  Very elegant prose.  SAT verbal score was kinda low so forgive me I don't understand this too well. Some scary things related to a D amplifier.  Wish I would've pursued an advanced degree maybe this would've helped.

"What contributes most to a change in how an amplifier sounds?"

amp designer, manufacturer, components incl. tubes, speakers, listening room acoustics, preamp incl. tone control feature etc., listener, music program and source, cables, RFI environment. 

amidst all of these really good comments there were no comments from people who actually build amplifiers that I could see. It would seem to me an amplifier designer is putting together an amplifier he would need to choose between lots of parts to create something that was good. I would love to hear what these parts are contained within an amplifier that impact sound which is really what it’s all about.

What is it about the transformer?? What is it about the wiring? What is it about the chassis? What is it about the chips? What is it about the capacitors? What is it about the power of the amplifier? etc