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?


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Adcom 535 ll. Nelson Pass design. Picked it up at the local flea for $40 and invested $100 to get it in top shape. Won't ever get rid of it, will always be my backup. Typical Nelson Pass detail and transparency. Specs state 40 watts/channel but like most Pass products a very moderate rating.
The Sim audio w5 was an unbelievably good sounding amp especially for the money it was $5,000 Canadian.
Any fans of Brown Electronic Labs (BEL) out there?    I had a 1001 MkII, was sad that I let it get away, so had to pick a MkV the first time I found a used one.    Wonderful amps!
I’ve the pleasure of owning as new vintage Yamaha amplifiers. A Pc2002m driving 4 infinity infinitesimal 0.2’s wall mounted.
A Pc4002m driving 2 base towers, and finally a Pc5002m driving the 2 mid/treble
panels. The Beta’s will drop to 1 ohm so certainly in efficient. The sound is clean with clipping out of the question if you intend on staying in the building. I’ve seen a few big name amps smoke trying to drive these speakers. Won’t be selling any of this stuff anytime soon. 
Cheers 
Hafler DH-220 bought new in 1984 for $329 - which is what a used version is worth today. Still drive my MG-1.5QRs very well.