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
Imho....the majority of 'new' anything hasn't improved to any great degree of late.  Most boast of various 'n sundry, but it seems to come down to ones' preferences in the interactions of the other components before and after 'Item X' in the space listened within....

It seems that one can always find 'flaw' or shortcomings in Anything.

One persons' Yay is anothers' Meh....
It's commented upon daily in these forums...

The Daily Kvetch...The emperors' new robes are still transparent, and his 'short comings' are painfully obvious. ;)
@coffee-jerk: I have the first production BEL 1001. Serial number 0001. Bought from the original owner who got it directly from Richard Brown.
@ Sheridan 

Please expand on the mod you might do to your Pass x350 that would yield a big improvement. Maybe it also applies to my X5. 
B&K EX442/ST-140
PS Audio 200C/CX  
VSP Labs Trans Mos 150
Acoustat TNT120/200
Moscode 300
Berning EA230
Onix OA21/21s
Tandberg 3012/3012a