All,
I just wrapped up one of my MK3's and I am having an issue. It HUMS like mad as soon as the B+ comes on. So Im looking through everything I've done, and I realize that the SDS board isn't grounded to anything....Is this correct ? Seems odd..
The connections I have are (from top to bottom):
Pin 8 from the 5AR4
Choke
Choke
Line to K
Line to J
That's all...Nothing to ground.
Thanks !
PS - maybe something else that may help - Im able to get -76vdc at the wiper of the bias pot...Sound OK ?