The other day it started to hum intermediately and I went to check the bias voltages (admittedly I have not been good about checking/adjusting these regularly). The front left tube was not not glowing at all. I shut off the amp, swapped the output tubes with a set of EL34s I had and turned it back on, it kept blowing fuses when I tried to turn it on.
I swapped my ss rectifier for a tube rectifier, it glowed bright, my front left output tube glowed bright and burned out and it looked like I "let the smoke out" of something on the right side of the amp and burned out the fuse. I swapped the burned out tube and turned it back on to see if I could figure out what was going on. All the tubes glowed and it did NOT blow the fuse but I had no bias voltage on the front tubes in both channels. I then replaced the quad cap thinking that's what had run out of smoke but it did the same thing. I checked voltages on the amp and everything other than the front tube bias voltages seems to be within range.