50w pp 60hz preamp hum...

[joshdfrazier]

yes, i have moved wires around while the amp was on, and i think i have the placement as good as it can get given the circumstances. i should probably invest in some shielded wire for such leads...

anyway, the hum has been fixed, or at least reduced to acceptable levels.
pops, you were right about the tubes. i suppose this amp is just hyper sensitive to faulty tubes?? i popped in an old hammond 12ax7 and it has vanished.

now to tackle this presence control feedback...

[sepulchre]

If the NFB is howling try swapping the primary leads to the OT.