Fender Super Six squealing

[georgeg587]

I have a 1972 Fender Super Six Reverb that I put away in storage about 10 years ago. At the time the amp was working perfectly. I just took it out and found that when I turn the reverb knob up to around 5 the amp starts to oscillate with a loud squealing. I changed out the reverb tube without any success. Any ideas?

Thanks

[Baconator]

I think the screaming is from the vertebrae in your spinal column - it translates to "put it back, put it back!!!":eek:

Sorry, I couldn't help myself.

[Blue Strat]

Is the reverb tank padded? If not, you'll need to do this. If it is, try stuffing some more padding on top of the tank and see if that helps. This is a common problem with tanks that are padded insufficiently.

[georgeg587]

Thanks Blue Strat but the problem is there even with the tank disconnected. I have swapped out the tube for the reverb section but no good. I have disconnectede the reverb tank and footswitch and it is still there when I tunr the reverb knob up to about 4. The pitch is very high. As I increase the reverb knob the pitch lowers but the volume stays the same. The Master vol controls the loudness of the squeal. The regular vol for that channel has no effect. I have resoldered the grounds but still no help. If I engage the vibrato it will fluctuate the squeal. Most unusual.

[JJman]

Did you check V3 or V4? They are both related to the reverb and only v4 is involved after the reverb control and/or if you pull the pan's cables.

[BassHog]

I have a Plush P1000S that is doing the exact same thing, it's a clone of your amp as well. This thing is frustrating me as it's not the tubes, the resistors all check out fine, everything is connected correctly but massive squeal above 5 on the reverb control. It doesn't matter if the tank is connected or not.

anyone figure this sort of problem out before?