Ok, so I replaced the one rca input on the one of my new paramours that has been giving me some hum problems, and was also able to strip the jacket back a bit further and solder a new end into the jack, and I still get the hum in this amp. Realize that I don't have a manual handy, what else should I check at this point?
The symptoms are as follows: I make all the connections to the amp, insert the tubes, plug in the power and then turn the amp on. It has a very mild hum -- hardly audible -- for about 3-5 seconds, then there is a small pop, followed by a much louder 60 hz hum. When the source is playing, there is no residual music behind the hum, and the hum balance pot has no effect whatsoever. Now, these amps were supposedly working perfectly (and I have no reason to doubt the seller on this), so any ideas what may have happened? This same set of symptoms is consistent with every power up cycle. Also note that this is the amp that did not have a loose output transformer, so I don't believe any physical damage occured on this input side of the amp, and everything, as far as I can tell, looks ok on the other side by where the plate choke was loose.
Thanks,
Jim
Jim Rebman -- recovering audiophile
Equitech balanced power; uRendu, USB processor -> Musette DAC -> 5670 tube buffer -> Finale Audio F138 FFX -> Cain and Cain Abbys near-field).
s.e.x. 2.1 under construction. Want list: Stereomour II
All ICs homemade (speaker and power next)