01-04-2017, 10:30 PM
It sounds like either a filter cap is failing, or the insulation between the 5 v filament winding of the power transformer and ground is breaking down. With the 5Z3 removed, there will be no B+ on the filament winding, so the leakage to ground will not show up.
You can disconnect each filter cap one at a time, but it would be better if you temporarily replaced it with another cap. Otherwise you will subject the speaker and other components to a lot of AC ripple voltage.
Since the problem still shows up without the rest of the tubes installed it would be better to test with just the 5Z3 plugged in.
You can disconnect each filter cap one at a time, but it would be better if you temporarily replaced it with another cap. Otherwise you will subject the speaker and other components to a lot of AC ripple voltage.
Since the problem still shows up without the rest of the tubes installed it would be better to test with just the 5Z3 plugged in.