Old Amps that can still Kick Butt


Not being a believer that time necessarily = progress, I would like to offer the following example of a sonic gem that has transcended time and can totally kick butt in a modern milieu:

The Robertson 4010. I got one of these about two years ago because it was in immaculate condition, the price was so low and I was inquisitive. I hooked it up and let it warm up for a couple of days. OMG this thing was in the super amp league: Transparency to die for, slam that you couldn‘t‘ believe for for a 50W amp.. Peter Moncrieffe wasn‘t wrong in his review of this amp: this thing is in the Sterreophile Class A component category hands down. Even after all these years.

What amps have you encountered that have defied time and can still kick butt today?


128x128pesky_wabbit
Pair of Krell KMA 160, 160 Class A that can handle any speaker load thrown at them. 
@douglas_schroeder  Your admiration of Class D amps is interesting. Have you heard some of the better amps mentioned in this thread? My example of the ARC D70Mk2 or the M100's for instance...each of these shows up all of the bleached and bright sounding Class D amps that I have ever heard. YMMV.