Marshall TSL 122 hum and V8 cap ID help

[Jazz P Bass]

"I’m not getting signal with two inner tubes."
What exactly do you mean by 'inner' tubes>
From left to right:
The first 2 tubes are in parallel.
The next 2 are also in parallel.

[Enzo]

Well sorta. Each power tube has its own heater fuse. And each has its own screen resistor. Either open makes a silent tube.

[beedoola]

I got some new El34's for another project and tried them and the popping sound went away.

I realized one of the pins for the phase inverter was bent and wasn't making full contact with one of the pins.

Amp seems to be working fine now and hitting the chassis with new tubes doesn't replicate the crackling issue. I imagine the old tubes are original. Got a new set of EHX on the way. Also have a bias module board to fix the bias drift issue these are notorious for.