I am still getting a bit of a 60 cycle hum that can be heard between tracks even when the volume is all the way down, when it's turned up more than 10 oclock or so it starts to get louder and is annoying. I guess I must have a ground loop or something but not sure where and so far I can't get rid of it. I still have to finish up the wiring for the TAPE INPUT slider and the SPARE input.
Do you think the old balance pot could be responsible for the hum?
I did replace the 12X4 rectifier tube with one from another PAS3 that seemed to reduce the hum, but as you can see on the pictures it's still there. As expected hum coming through the PHONO is louder than when using the other inputs. When the selector is turned to an unused input it's dead quiet.
Could someone point me to a good suitable replacement for the balance pot?
Any help or ideas would be appreciated.
Here are some pictures of the wiring and a couple showing the hum as seen on my scope. The trace showing the more complex wave is from the line stage board while the trace with the more saw tooth wave is from the PHONO. It measures at 60 Hz.