Human psychology is a curious little maze of twists and turns, corkscrews and loops. Hand someone a warm beverage in a warm cup, and they'll have a completely different take on the next person they meet, without having any idea that the beverage in their hand is having a huge influence on their impression. Wine decanted from a clear bottle will, across the board, get poorer grades than the same wine decanted from a dark green bottle, and so on. Eyewitness testimony given by good, honest people on matters that would seem to be relatively clear--5'7" or 6', blue car or brown?--on matters of life and death is notoriously unreliable.
I love my tube amps. Am I positive that my perception of their "warmth" and their sounding "open" and "alive" isn't as much as anything else a matter of my seeing their warm orange--and sometimes blue--glow inside a glass bottle (like a soul inside a body), and that my perception of the deadness of solid state isn't just a matter of my not seeing any glow, not seeing any space between filaments and glass, but on the contrary, seeing plain old "solid" transistors, with no space, no air--you know, like a corpse?
Like the original poster, I think copper sounds richer too. But of course copper is a richer color than silver, which is bright, and in some lights, even harsh.
