06-11-2016, 08:24 PM
(05-26-2016, 11:33 PM)Hangman Wrote: Hmm, is the hum balance pot the original one? I have seen those pots fail and when they do, they behave exactly like you were saying:
"it's quietest at one end of the rotation and picks up some treble noise as I rotate it the other direction."
If you don't have another 100 ohm pot around, try using two resistors as fender did.
Thanks Hangman. I installed a Fender replacement hum pot and it seemed to help a little but the hum is still pretty bad and the behavior is still the same. I've pulled each preamp tube one at a time to try to isolate the problem. The only way to quiet this thing is to plug something in at the power amp input jack -or- pull the PI tube. (related?)question: some of the caps according to the schematic (besides the PS filtering) appear to be polarized. C12, C14, C15 and C202 are good examples of what I'm seeing. Are these supposed to be polarized electrolytics or what? I'm grasping here, any help really appreciated.