My 1974x amp is quiet when nothing is plugged into it, but as soon as I plug my intrument cable into the non-tremolo channel, I get this awful cyclic noise. Does anyone know what to do? I replaced the ECC83 tubes one by one (testing it between each tube replacement), but it didn't fix the problem.
Here's a video of my problem.
I was just playing my Epi on the Acoustic setting and all sound went out and the screen and buttons started flashing. Tried pluggin/unplugging. Pluggin into a different outlet. What the hell just happened?