If you have a hum problem, try this

[CeeBee]

I haven't had that problem yet, but I can imagine some of you guys using lots of equipment could, check this video

[rayc]

I saw that...they aren't cheap and there're a lot of isolation transformer do dads on the market for stereo gear etc. I'm still dealing with the RFI EMI stuff at my location but this or similar would be nice if needed once the BIG probs are solved.
Currently I run any DI'd equipment into my BDI21 as it has balanced out as well as a ground lift. That combo seems to solve most issues.