Jeffreybehr - Don't fire your electrician yet. Even with great house wiring you can still get induced ground current inside your equipment and have ground loop problems. E.G., I think Jim Hagerman might have some info about a star ground configuration he used on his trumpet phono pre-amp to try and minimize the problem (WWW.Hagtec.com, or something like that). I think your comment about getting the house wiring right is on the money, but good equipment internal design (and/or a little luck)is also part of the issue.
