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AC regenerator through audio rack causing speaker buzz

This appears to be a highly esoteric problem, yet it is true nonetheless.

I have a Monarchy AC power regenerator. It powers up fine on the carpet no buzz problems.

However, if I power it up while on the Adona audio rack, there is an audible electricity-like buzz through the speakers.
It is audible with your ear right up to the driver. Below are some graphics, photos, and an mp3 file for you to study.

Ambient system hiss, turn-on thump, and subsequent buzz riding on the wave

Turn-on buzz mp3 file


The facts are:

-Not an EMI issue. I can hold the AC Regenerator right on top of the amplifiers, buzz doesn't appear. ERS sheets do nothing for this buzz.

-Not a mechanical transformer noise. I cannot hear the transformers in the AC Regenerator with my ear next to them.
Also I tried Vibrapods under the AC Regenerator feet, but on top of the rack the buzz is still there.

-Not a power cable noise. I have nothing attached to the AC Regenerator at the moment, and moving its power cable around does nothing for buzz loudness.

-Racks are granite with mdf damping, and steel supports, and brass spikes. The subflooring is concrete. Speakers, subwoofer, all racks are on brass spikes.

-The AC Regenerator has toroidal transformer AC input, DC filtering, sine-wave frequency generator, and toroidal transformer AC output.

-Top shelf has tube preamp, middle shelf sacd/dacs/reclock/ground, bottom shelf ac regen

I originally suspected the AC Regenerator was dumping trash or DC into the electric wiring, but if that was the case it would be audible whether on the Adona rack or on the carpet.

Next, I suspected some type of ground loop contamination, but why doesn't it disappear if I use a cheater plug? And why does it disappear immediately if placed on carpet? I've already acquired the $600 Granite Audio Ground Zero and it won't solve this specific buzz.
Although it did silence some existing system noises and helped me narrow it down to the AC Regenerator.

Totally confused, because this appears to be totally esoteric.



Edits: 07/18/09 07/18/09 07/18/09 07/18/09 07/18/09

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Topic - AC regenerator through audio rack causing speaker buzz - Adriel 09:22:14 07/18/09 (17)

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