Back to that noisy reverb

[glasman]

Per chance is it motorboating due to positive feedback. The 10K tap resistor does not provide much insolation. If the input and output are in phase it is possible that you are getting an oscillation.

Try reversing the wires on one side of the transfomer.

Gary

[MarkB]

Could it be the shared cathode to ground, with other paths to ground in between? What if the V3b (the 2nd recovery stage) cathode had its own bias resistor (and optional bypass cap)?

I'm thinking the shared cathode is setting up a nice ground loop there, in parallel with the internal resistance of the tube, perhaps.

Well, I tried it, no change. Damn this is frustrating.

Time to pop for an o-scope?

[mlp-mx6]

Do you have another reverb tank to try it with? (perhaps the problem is the tank?)

[Bob-I]

Per chance is it motorboating due to positive feedback. The 10K tap resistor does not provide much insolation. If the input and output are in phase it is possible that you are getting an oscillation.

Try reversing the wires on one side of the transfomer.

Gary

Tried .... didn't help

No I don't think it's a feedback issue. Somehow I'm getting noise on the input of this stage.

[Normster]

Mostly OT, but I saw Paul Rosk on ampage offered to do a partical realignment on your caps for only $20 each! LMAO

[groovtubin]

Mostly OT, but I saw Paul Rosk on ampage offered to do a partical realignment on your caps for only $20 each! LMAO

Now THATS funny!! jim

[Bob-I]

Mostly OT, but I saw Paul Rosk on ampage offered to do a partical realignment on your caps for only $20 each! LMAO

What????? that's not worth the $20???

I thought it was a good deal.