Hello to all.
An K200 B-1 I've been rebuilding has begun producing a loud LF pulse with an instrument plugged in when I get beyond 50% of throttle. This occurs only on Ch 2. Shorting the 500pf cap (I replaced it when the problem began) between the input jacks is a help. but not a solution. Any thoughts or suggestions would be welcome. BTW all transistors are modern parts.
Thanks,
HR