Emu XL-7 & MP-7 User's Group

Hi all,

I've posted this question a while ago, and got no replies.
But the problem hasn't gone, and I really want to do something about it.
Any hints/tips will be greatly appreciated!

So:
- the first time I mentioned phone outputs only, but actually the buzz 
is present in main outs as well;
- its' loudness is constant, not affected by master volume at all;
- this looks like a stupid grounding problem - maybe someone familiar 
with the innards of a command station has an idea *where* it can be?

Cheers!
Boris.