Dealing with Starfire III DeArmond hum

[swiveltung]

Flourescent lights, light dimmers, heaters and fans on the same circuit will cause hum.
Of course many old buildings have issues. Wall outlets wired wrong. 3 prong outlets that really only have 2 wires inside!

I tried a Hum Debugger in a gig that had big issues. It did nothing. Zip, Zilch.

One thing that helps is to put a metal /copper plate/shield under the body where the pots are. Ground that plate to the bridge or tailpiece. I did this on a semihollow recently and it helped a ton, even though the bridge was already grounded, the plate seemed to work as a shield.

The other option is to get an isolated power supply, like a Furman. Beware that these only really do the job once you get to about $350 or so. (last I investigated) That's a lot for a fancy "extension cord"
I've wondered is using a Variac would do it? They sell Chinese ones for <$50

 

[Nuuska]

Isolation transformer might be good - but then you would have to provide the ground connection - and make sure to avoid contacts to non-isolated units.

Variac is just a potentiometer - cuts the voltage to your choise - but no isolation - it is so-called "half-transformer"

 

[Default]

Flourescent lights, light dimmers, heaters and fans on the same circuit will cause hum.
Of course many old buildings have issues. Wall outlets wired wrong. 3 prong outlets that really only have 2 wires inside!

I tried a Hum Debugger in a gig that had big issues. It did nothing. Zip, Zilch.

One thing that helps is to put a metal /copper plate/shield under the body where the pots are. Ground that plate to the bridge or tailpiece. I did this on a semihollow recently and it helped a ton, even though the bridge was already grounded, the plate seemed to work as a shield.

The other option is to get an isolated power supply, like a Furman. Beware that these only really do the job once you get to about $350 or so. (last I investigated) That's a lot for a fancy "extension cord"
I've wondered is using a Variac would do it? They sell Chinese ones for <$50

'tung, check out the Bisonic hack thread in Tech shop.

 

[swiveltung]

'tung, check out the Bisonic hack thread in Tech shop.

Cool, i had thought of trying the pickup shield on a hollowbody before, but never really need to do it. Good info though.

 

[rbrcbr]

Thanks for the input everyone. I will definitely look into the outlet tester. This apartment has some dimmers in a couple rooms but they don't work very well, I can imagine they still add to the hum though. I've got a furman power conditioner but it's not the $300 one or whatever, it didn't make much of a difference when I bought it. I'll start with an outlet tester and go from there I suppose. I'm hoping to move to a new place in the spring or summer, so hopefully it's a newer building with less of these issues.