[floresjc]

For clarifcation, when you say 'nothing upstream' did you disconnect the rca interconnects from the amp or just not turn the preamp on?

Yes, I disconnected the RCA cables. Only thing attached was teh speaker cables and power cord.

[floresjc]

Frank -

Thanks for your insight and your timely email help. 

[AVnerdguy]

Just following up - been offline a few days. Sorry the tube swap didn't do it. After reading the rest of the posts I didn't realize you had noise in the other channel as well. I'm sure Frank will get it up and running as good as new. Let us know how it turns out.