One of my buddies is having hum problems in his home studio. He asked some advice on getting rid of hums in the studio. He is Q, I am A:
Q: First of all the outlet I have isn’t grounded, and there is only one in the room. So I know I need to get the electricity grounded.
A: You should have all the gear on the same circuit, and only ONE piece of gear grounded to the wall. Use those little orange lifters on everything else. If you ground to multiple locations that’s where the hum comes from.
Q: It’s still humming a bit if I run an extension from a grounded outlet, so I think that my next course of action would be to replace all the dimmer switches. But would this need to be by the circuit they are on? By vicinity if they are not in the same area?
A: The dimmers may cause a problem if they’re on the same circuit, or if you have guitars and other items which pick up the RF. Turn the lights off and see if the hum goes away.
Q: Route power cables separate from audio cables, and if they have to cross, do it at right angles?
A: If you have shitty cable I guess. I never needed to worry about that. I just had to worry about power supplies getting too close to each other so their magnetic fields interfered with each other. Get rid of the Radio Shack cable and get some Mogami or Canare cable.
Q: Any other suggestions? Have any of you had luck with power conditioners and such? Replace the Alesis RA-100 with a better amp? Run only balanced cable? Add isolation transformers? Buy new cable? Buy cases for the computers that are isolated? Buy LCD displays instead of CRT’s?
A: Maybe the CRTs might cause some problems. Turn them off and see if the hum goes away. That’s a similar situation to the dimmers. I’ve never had to go the power conditioner route. The RA-100 wouldn’t be the problem. Balanced cable can’t hurt, but I’ve had hundreds of unbalanced connections at my place with no hum problems. GET RID OF ALL BAD CABLE, GROUND CORRECTLY AND START FROM THERE.