Hi, NAD, trouble and a question

All in one post. Joined a number of years ago to browse and IIRC to ask a seller in the classifieds about a Subway Blues amp. Many moons and phases of life later, it's my first post as a purple and wheat Subway Blues made its way home this afternoon. Actually bought one of these the first week they were out (fall of 94, I think?) and remember the wait from product announcement to delivery at Reliable Music in Charlotte. All that to say, excited to have come full circle.

Or I will be.

UPS appears to have been kind to the amp: the box, interior packing and the amplifier itself are all in pristine shape. But upon installing the tubes and powering up, I have a loud electrical hum. A preliminary sweep of the interwebs suggests three possible culprits: the power tubes themselves, a cap value near the power supply, and resistors tied to the power tubes.

Comfortable looking into those first two on my own and open to resources on the third. Anything else that may be a straightforward diagnostic? Looking forward to the little fella feeling himself again.

Michael

Could also be your electrical supply. Have you tried a different outlet, or another amp on the same circuit?

Reseated all the tubes and we're in much better shape. Down to what is, to the best of my understanding, the expected noise floor for the amp. Gotta find my caps and see about the .01 > .68 change that seems to be the next logical step.