I don't know whether Bryston 4B-ST can be considered as vintage. I remember reading some comments about these amps being used in some night clubs and discos by DJs, and that cigarette butts are discarded on top of them and drinks spilt on them, and after continuous play at near clipping levels the amps never failed.
Also, I read somewhere here about the Krell KAV-400XI being dropped from a waist-level table onto a concrete floor and come out fine, although the concrete floor was chipped. Certainly built like a brick.