ANyone out there know vintage effects? I have a Fender Reverb, blackface era. When I first go tit, the caps were stock (40+ years old), so they got changed out. I changed out the tubes, and I replaced the 2-pronged power cord with a grounded cord. This was fine for several months, until recently. The unit sounds fine in bypass, but when I switch it on (which, honestly now, is all the time), I get a nasty buzz. If i adjust the Spring Dwell, no change. If I adjust the Tone control, it changes the tone of the buzz. When I adjust the Mix control, it increases in volume as I add more wet signal. So yeah... I know it's in the reverb circuit itself. I'm hoping it's not the Power Tube, as it's a 6K6GT, and difficult to find. It might be the 12AT7, or the 12AX7/7025... or it might be something completely different. Anyone have any thoughts or experiences they can help me with?