Amps from the 1980's -- What gear holds up sonically? Reliably?

Phase Linear are still great amps and some still sound great in relation to modern amps. If they still work your all set but if not there are a few places on E-Bay that will get them back to Snuff I use Circle Stereo in Texas. You had the 400's 700 and 500 and the newer ones had a B designation and had  different meters  and they still sound as good as most new amps and maybe better after being rebuilt. I still have all of these and I can't get myself to part with them. And by the way Pink Floyd used too use the 700's stacked so that goes to show how good they were. Look up the most influential amps of all time and you'll see the 400 as right up  near the top. Bob Carver was the guy who got the ball rolling as far as high powered good sounding amps. I am 72 and have heard them all. Most important is the Pre amp as that will make the big difference and a lot of new ones have made great strides as far as better sound.

Reading one post they were known as flame throwers that is because of people pushing them too overload like a junky the more you turned them up the better they sounded until blow up time if kept under the o dB point no problem. I've got two 400's that have never been touched but the ones heavily used will need the electrolytes on the circuit boards as they  definitely need to be replaced to last another 30 years  Even with the rebuild they still would be a lot cheaper than some new ones