Phantom Power Hum/Buzz

[fuzzyween]

I use Grace 101 preamps for all my condenser microphones with a Korg D1200mkII multi-track. When I turn on the Grace 101 preamp phantom power I'm getting a buzz/hum in my system on 2 of the tracks even when there are no mic inputs into the Grace 101's on those tracks. I've never had problems with these preamps in the past and the only thing that has changed recently is that I've plugged a few more wall warts into my power strip. I've tried redoing my mic cables to stay as far as possible away from the wall wart transformers, but that didn't help. All of my hardware is powered through a power strip that plugs into a single wall outlet.

Any suggestions? I'm thinking about buying an external phantom power supply or maybe will try out an ebtech Hum Eliminator. Using the mult-track phantom power instead of the Grace 101's phantom power does solve the problem, but the Korg D1200mkII only has 2 of it's 4 inputs outfitted with phantom power and I'm using all 4 inputs.

 

[PhilGood]

Have you thought about getting a filtered power strip and plugging the gear into that, then moving all the wall warts to a seperate strip?

 

[northsiderap]

Power supply filtering

I agree - - - For every new thing you plug into a circuit, the loads on that circuit induce a distortion on your 60Hz sine wave coming from your outlet.

Make sure neutral is only tied to ground at the panel if possible. You'll get more THD in your power if not.

Run a new circuit if you can. If not, a couple of high quality power conditioners might do it.

 

[thane1200]

Have you thought about getting a filtered power strip and plugging the gear into that, then moving all the wall warts to a seperate strip?

Ditto! OR Separate circuit.

 

[Treeline]

You mentioned that you changed your mic cables. Have you done that with the patch cords from the Grace to the Korg as well?

Another thing to check is to see if any other source plugged directly into the Korg will give you a hum - rule out a loose ground at that end.

A third thing is to swap out the power feed cords to the units. Sometimes those fail and they are easily overlooked.