Buzzing noises from power supplies

[Magic Matt]

Sometimes when we go to venues, my guitar picks up noise from the power supplies we use for things like the cordless mic, and the lighting. My solution most of the time is simply to try and stand further away from it, but in smaller venues this isn't always possible.

I wondered if I could screen the power supplies to eliminate, or at least reduce, the problem? Can anyone recommend anything? I have some electronics knowledge so the idea of opening up[ power supplies and putting them in different cases etc. doesn't bother me.

[iiipopes]

Welcome to the world of single coil pickups. This is the very reason humbucking pickups were invented. I am going to guess you have a Jazz bass, with its single coil pickups, they are antennae for hum and electrostatic noise. This is also why I have changed out all my single coil pickups in almost all my instruments for humbucking versions.

[Magic Matt]

I have a standard P-Bass, and a Fretless Jazz Bass. I don't really want to modify the guitars if screening the power supplies would work.

[HowieBass]

You might be able to screen your own power supplies (put them inside Faraday cages???) but there's always the possibility that other devices inside a venue will have exactly the same problem with unsuppressed noise. IMHO the first place to start sorting this out is probably get your basses well screened (assuming they haven't been done already) with conductive paint or better, copper foil lining all the cavities and the scratchplates to see how much this reduces the problem. After that if you still have a noise issue I think you're looking at getting noiseless pickups for the Jazz.

[Magic Matt]

Generally it's not a problem, it's only when we're in a small venue and I have to be in close proximity to a couple of power supplies. I hadn't considered conductive paint - if I made a very simple plywood box, and painted it with that, then put the power supplies inside it, do you think that would make much difference? Obviously that's a lot cheaper than buying decent noise cancelling pickups etc. and I could possibly paint inside the bass as well.

[Magic Matt]

Do I need to ground the paint, or is it enough just to be a "cage" ?

[zero9]

A lot of cables etc grouped together and running across each other, can induce hum. If that's not the situation when you gig, ignore this, otherwise, separate the cables as much as possible and see if that reduces the noise.

[icastle]

[quote name='Magic Matt' timestamp='1414518587' post='2590183']
Do I need to ground the paint, or is it enough just to be a "cage" ?
[/quote]

Yes you do.

[Magic Matt]

Well I gave it a go - seems pretty successful! I simply painted the inside and outside of a plywood box with it, and tied it to Earth, then put a 4-way inside the box for the power supplies to plug into. I'd say the buzz is still there a little, but it's reduced by probably around 80%, so only really noticable if I bend down right near them, and to be honest I get the same hum then as I do if I stand right near my amp.

Thanks!

[HowieBass]

Good stuff!