I had to take the reverb unit out of my Peavey Valveking because it was buzzing so bad. No real loss for me. I am just not a fan of reverb. Good luck. I hope you can find a solution.

I’m using a reissue ’63 Fender reverb unit as well and seeing the same thing. The unit works fine if the Dwell is set below 3, but at 3 or higher, the speakers on the amp seem like the coils are blown, adding a buzz in the sound. I’ve replaced tubes, popped the back off and measured voltages at various “test points” as shown on the schematic that came with it. Mine was not used and I have had the unit for 20 years, since ’93 when it was reissued. I also plug that into a Bassman, but a custom 2 x 12″ built from a ’59 reissue head and a 4 ohm output transformer for 2x speakers. I will test with other amps. Wondering if you ever found a solution, a few years ago.

Thanks for the reply. I did resolve the issue with the Reverb unit that I was experiencing, which was a buzzing of various intensities depending on the setting I used on the Reverb unit. I may have been using some substitute tube types in the unit and also in the amp, and when I returned the tubes in the unit to stock then things improved considerably. I also switched out the tubes in the amp for lower gain, 12ay7 in v1 and 12at7 for the phase inverter and it totally cleaned up the buzzing and funky sounds. I realize the problem could actually be more with the amp and how the current amp components react with the higher gain tubes, but the sound is very good to “primo” that I get now with the stated tubes. I find that the low gain preamp tubes actually allows me to use higher settings on volume, mids and highs than before and this seems to get the amp to a sweet spot under a very playable volume. I’m a harmonica player and prefer a cleaner sound with a bit of crispness, and then some crunch when I overload the mic.