Hello all, picked up a 65 reissue twin reverb couple weeks ago. When I got it. It had a ungodly loud hum from the power section. Took it to tech. 1 filter cap was bad, and 2 preamp tubes aswell. When I got it back hum totally gone. Now with humgone, i have more power. But a new issue. With amp on 3 and picking certain notes, particularly higher register ones. And the high notes in full chords I get this ratty buzz on top of those notes. Louder amp gets worse it appears. On 6 full chords roar with the ratty buzz and turn to mush. Light picking sorta fixes that. I'm confused as to where to start. It has the original groove power tubes from 15 years ago, but tech said they tested fine. Tho he didnt recall where bias was, but it was "checked" crossover distortion? Bad power tube,? Speakers? Bias? It's a nasty roar of a ratty buzz. And always remember twins staying clean till about 7ish with singe coils.. dont know where to start.. but think bias should be first in line. All 4 power Tubes are all super purpleish. But I'm color blindish aswell.. I allerciate any direction and apologize for such basic questions. Gotta learn more..