Hello, can anyone help me diagnose this type of problem, this amplifier Was working perfectly then one day started to do this motorboat sound from the speakers, when i checked the tubes were alternating like the video attached, the sound persist if you don’t have anything connected, it does change or affect with the MV, the first time I checked and changed the tremolo roach, it did stop for some time but now is back again, have never seen this type of problem, thanks again for the help guys.
Check out Psionic Audio on YouTube. He has a lot of info about repairing old Fenders and other guitar amps too.
Doubt it, this were replaced on 2019 and the amp has been sitting only for recording, but i will check the caps, its important to say that this amp was completely serviced meaning all caps, cables, resistors, tubes, sockets, are new, also it is blackfaced, weird thing to me it is that it worked well, its just now that is doing this, as i said it did once before but i checked the tremolo circuit replaced the roach and it was good to go, how would you call this problem? I can’t find no one with similar symptoms, thanks for the reply.
SOLVED, I checked all the power supply filter caps and lines, this took me to the resistor at the bias adjust knob inside the amp, was cold solder and cracked, re solder and re heated all components in bias and i just recently tested and seems to be good by now, thanks everyone for pointing me the caps.