High Efficiency System- Noise Floor Reality Check?

Well, no joy yet. Got one of those Granite Ground Zero thingies, it does work, but it is not solving my problem (yet). In fairness to the manufacturer, I don't want to suggest that I have reached the end of all possibilities in using it- for example, where does one find a ground on the Shunyata Hydras? Those are the only 'components' in the system that have not yet been routed through the Ground Zero.

I also tried: removing everything plugged into the step down transformer other than the hi-fi system Shunyatas- no difference; running the Shunyatas into conventional outlets in the room that have nothing to do with the step-down transformer (and pulling the plug on the step down transformer as well). No dice.

My electrician came by yesterday- at first, he looked at me like I was insane for complaining about noise that you hear by putting your ear close to these big speakers- but, after a few minutes he acknowledged that he could hear it in the room, sitting nearby the speaker, not right on top of it.

He is of course willing to install a separate subpanel for 240, giving me the option of either leg to experiment with and setting up yet another group of dedicated lines with an isolated ground. This will involve some cost and some breaking of walls~ so i've been trying to find solutions short of that. The killer, though, would be for him to do all this work, and for me to still have the hum.

I suppose he could rig up something temporary to see if it does the job, but the distances are more than 50 ft. from the main panel to the room- and three floors up- I wonder if he has a really long extension cord?

Any further thoughts on this, gang?

BTW, got a Monaco amp stand with the carbon shelf and footers from a fellow 'Goner yesterday- wow! Sort of like
taking your car out of the mud and driving it on smooth, fresh pavement. The fact that it is gorgeous doesn't hurt,either.

This noise problem is driving me a tad crazy, though.

(OH, yeah, I'm supposed to get my new TT today too, so
at some point, this system is going to reach its potential).

The 60Hz hum in the subs may be from poorly shielded or oriented power supply transformers in the sub cabinet. I belive the Avantgardes use internal amps for the subs, yes? If they do, have you tried running them straight off the wall socket with no filtering? If you get a similar 60 cycle hum, you've got an inernal noise source--that is, the mains transformer. Opening the speaker (yikes!) and carefully shielding the transformer with ERS cloth (*don't short anything*) or similar could help. A more simple method of banishing such hum from a component builder's perspective is to change the orientation of the transformer. In other words, unmount it from whatever it's attached to and simply turn in from it's origial mounting position and listen for changes.

If the mains transformer is in a separate chassis from the subs, you can try similar things and it's easier since you don't have to open the speaker.

Not sure about the sound from the horn, but it doesn't sound like a tube issue as the volume doesn't increase with settings.

Hope this helps--we all can get a bit neurotic about this. As I recently said to my audio bud, this sometimes seems more like a support group than a hobby group.

Enjoy.

Thnx Doug. Interesting angle. I'll call my buddy Jim Smith about that- he was the importer 'til recently.