You are not my amp tech, but maybe you can help me diagnose the source of a strange noise on a brand new guitar amp.
Yesterday, I got a tiny tube amp
in the mail. After letting it come up to room temperature, I plugged it into a cab (yes, with the right impedance) and played away. No problems at all; made some really nice sounds, by the way.
The next time I turned it on (an hour or two later), there was an awful static noise--sort of like rushing water, or waves crashing--even with the volume all the way down and no guitar attached. Playing through it produced pops and crackles and unpredictable volume changes, and the static continued.
It's got 2 12AX7 tubes (and a funky setup--V1 and one triode of V2 are the preamp, and the other triode on V2 is the power tube). Best I can tell (which is not saying much), they both look normal, glow a healthy orange, aren't microphonic.
Now, the head is brand new, so there's a really good chance it's going back to the vendor as defective, but out of curiosity (and future diagnostic needs), what could the problem be?