Originally Posted By BBIBH
Originally Posted By brendo
My building has lousy grounding.

Yes, industry learned a hard lesson when business systems installers grounded to the nearest fire sprinkler systems and that industry moved away from having the water supply heads loaded with water at all times...bad things happened man, bad things!

Originally Posted By brendo
I also added new receptacle{PS Audio} with an extra ground line to the receptacles box. For me these made a great difference, especially on my noise floor.

If you can - and certainly for new builds/construction - I generally recommend dedicated circuits with isolated grounds be receptacle. The cost at build is negligible and can be worth cost later

Originally Posted By brendo
Sadly there's no easy fix for such issues. Only process of elimination. Sometimes multiple fixes are necessary.

Agreed...but that is part of the fun isn't it? LOL

I do have dual dedicated 20amp circuits for my gear. How does one isolate the grounds?

My house has fibre lines coming in (one from Rogers, and one from Bell) in place of coax. Am I correct in thinking that fibre is immune to the kinds of noise that would be causing my issue?

If I listen to the Denon itself, it seems to make a similar buzz internally. Could it be that the unit has a noisy transformer that the pre-outs are sensitive enough to pick up?

Axiom M5HP VP160 M3 ADA1000
Anthem MRX 720
SVS SB-3000 (dual)