28-06-2020, 02:32 PM
When you pulled V3 and you lost the hum, did you try replacing V3 with one of the other ECC83s?
You could disconnect the transformer heater centre tap, to see what effect that has on the hum, ie does it get better or worse?
You could disconnect the transformer heater centre tap, to see what effect that has on the hum, ie does it get better or worse?







