6g15 troubleshooting

[joelw]

hi everyone,
I just finished my first tube project, and i'm having trouble finding the source of some unwanted distortion. I built a 6g15 reverb clone which works well except that it distorts when the reverb mix and dwell are turned up. It works fine when they are set to low amounts(at least i can't hear the distortion.) It is a sizzly buzzy distortion that sounds like it is on the reverb signal, not the dry signal, but i'm not sure about it being exclusively the wet half. Changing tubes did nothing, except a 6v6 in the place of the 6k6 made it worse, and a 12ax7 in place of the 12at7 made it worse. All the voltages are within 10% of the fender schematic, and the ot and reverb pan match well enough(8ohm output on the ot and 10 ohm input on the pan.) Can a pan be overdriven or damaged? could it be a bad output transformer? Could i be overdriving the 12ax7 even though the listed voltages are right? None of these seem that probable to me, but i can't think of what else it might be. Any help would be greatly appreciated.
thanks in advance,
joel

[acorkos]

try pulling the reverb tank out of the cabinet and see if it still distorts

[joelw]

Im not sure which you mean, but relocating the pan outside the cab does not help. Unplugging the pan leaves an undistorted dry signal.