Grounding

[FretlessOnly]

Not only was it the dimmer switch in the music room, but also the dimmer downstairs in the dining room. Oddly, the downstairs bathroom, which abuts the dining room, also has a dimmer which has no effect on the buzz. Must be something about how they are wired to the breaker box.

Just an FYI for those of you who encounter similar problems.

[jps]

The bathroom is most likely on a different circuit.

Unless you have an old house like ours where some of the circuits make no sense whatsoever!

[cjj]

I know that feeling. This house, originally built in the 1930's, added on to in the 1950's and again in the '70's makes no sense in all manner of things, including the complete roof that's in the attic under the present roof. And that makes more sense than the wiring...

[FretlessOnly]

Actually, our house was built in 1969 (replete with Zodiac cutting board built into the kitchen counter!) by our next-door neighbor who is a great home builder. Thing is, the one thing he's not good at is electrical stuff, so he had that farmed out. Now all I need to do is figure out how to dampen the vibrations from the electric baseboard heaters.