Thank you Phil! I'll check those connections and see if I can find the problem.

Hi all!
My Vox Super Beatle head has a good reverb tank, but it's developed a problem lately: no matter how low the volume is, if the reverb is turned up above 2 or so, it starts up a feedback howl. This seems to happen even if I'm plugged into a different channel where the reverb isn't in use. Does anyone know why this might be the case? Thank you.

Over a year ago, i bought a Vox Super Beatle head made in 1966. I've wanted one of these for thirty years. Being one of the first solid states, they have a reputation for unreliability, so I've taken it very easy on this amp head. I've only used it for recording sessions and kept it unplugged and covered otherwise. I haven't used it in a couple of months because I didn't have any tracks to record, until today. I plugged everything in, turned it on, no sound. I turned the volume up to levels that would be deafening normally, and could just barely hear the ghost of a guitar signal. The odd thing is, everything seemed to work. I could hear the tremolo  on the trem channel in that tiny signal, and when I changed the speed, I could hear it slow down and speed up. I heard the change when I turned on the fuzz. In the reverb channel, I could hear a tiny echo of reverb when I turned that on. It seems like it's probably a short of some kind, but there is NO REASON for it to be doing this. I tried changing the guitar cord, changing the speaker cord, using a different guitar, and plugging that speaker into a different amp (worked fine). Does anyone have any advice? Thank you.