buzzzzz, where did i go wrong?

did you tie the two audio ground rods to the house ground rod ? If so, that should negate the differences in ground potential so long as you have a good connection on all of them.

As to Dan2112's comments, treatment of the soil to increase conductivity is a temporary band aid at best. The soil has to be treated on a regular basis. Besides that, the chemicals are typically somewhat corrosive to metals and may cause premature rotting of the ground rods themselves.

As to floating the grounds of the amps, i don't see a problem with this. In Laura Dearborn's book "Good Sound", she comments on this. One "expert" said that he typically experiences better performance by floating the amp grounds than by floating anything else. Others state that you should select one component ( commonly the preamp since all components inersect there ) and ground it, letting all of the others float. This puts them all at the same ground potential. Others say that digital gear should all be grounded due to the amount of trash that they generate. Personally, I think it all boils down to trial and error.

Have you checked to make sure that the circuitry that the amps are on are of the same polarity as the other outlets ? I know you just had them professionally installed, but mistakes do happen. Also, have you checked to make sure that all of your gear is electrically oriented the same way ? This might help you also. Sean
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http://forum.audiogon.com/cgi-bin/fr.pl?htech&1014011751&read&keyw&zzhum

Good stuff so far, especially Sean and Rap. One thing is certain - having two separate ground systems (power system and ground rods) will cause trouble, especially with a 15v difference. It's not a component problem.

So pick your ground system. Either float everything and tie everything to the ground rod, or give up on the ground rods and use the power system ground. If you use three prong cords and tie to the ground rods then that 15v difference results in current flow through the ground paths (chassis, cabinent, etc) through the ground prong to the power system ground.

I don't know how old your house is, but I wonder if the power system ground is good. Sometimes you get corrosion in old electrical systems.

With your audio gear referenced to ground rods, you might get a slight tingle if you come into contact with a component chassis and some other appliance referenced to power system ground (like a metal lamp with a 3 prong cord) at the same time.

Hi Sean,

Actually when I said, "salt" I did not mean it that way I should have said electrochemical. The company that I have found that does this stuff grounds substations, towers and the like. Their system has a lifetime of fifty years and only requires a little ground moisture to work effectively. Of course this come at a price, but this is the real thing. Check out http://www.sgscorp.com/index.html for more info.

- Dan

OK this is starting to drive me batty.
Today's events included changing the main system ground. We also tried all combos of grounding rods including none except for the main system ground, 2 supplemental rods tied together, all on one supplemental rod...you name it I think we have tried it. we also went through the whoel house flipping each circuit on sequentially but no single breaker added to the buzz effect. It seems to happen after the preamp and teh digital end are tirned on. It is there when only the preamp is on and is slightly greater wheen the digital end is turned on. I am actually starting to wonder if my cables are a problem . They are MIT and are singled ended. Still moving the cables around has no effect.
i notice that cheating the amps takes away teh buzz leaving a small hiss. Maybe this is noise coming in on the neutral?
When you tie the grounds together does that just mean passing a copper wire between them? Does anyone have anyo other ideas?
JD

Maybe you should take the preamp to a friends house and see if it does the same thing.... - Dan