04-12-2014, 11:57 AM
Thanks. I will experiment with various C58/C59 values to find the lowest combination that kills the hum. Also will recheck the caps and resistors you mention. All caps have been replaced except micas, and all resistors more than 10% out of spec were replaced. I've checked C50,51,62 and R48,49 numerous times, but I may try replacing them one at a time in case something is failing under load.