Troubleshooting: a dual-humbucker guitar that hums

[Crowder]

I've just finished wiring up a Thinline, '72-style with two SD humbuckers (4 conductor), volume, tone and Gibson-style switch. It is dead quiet when I'm touching any metal parts, but hums when I'm not touching any metal. So a grounding issue is my first guess.

Even knowing this, I haven't been able to eliminate the hum and thought I'd ask for advice.

Here are more details:

-- The pickups are 4-conductor, and I've got the red/whites connected (soldered, folded back against the wire, and taped with electrical tape). I have the green and bare wires grounded at the switch, and the blacks connected to the switch terminals.

-- All the other grounds are soldered to the back of the volume pot. These include the lead to the input jack, the lead to the switch, and the lead to the underside of the bridge. The third lug of the volume pot is also connected to this ground point.

-- The hum disappears upon touching any part of the circuitry (pickup covers, bridge/strings, vol knob shaft, tone knob shaft, switch, jack plate).

Any ideas would be greatly appreciated!

Thanks.

[whiteop]

Shielded pickguard might help

[Dev...in]

I know this isn't the answer you want but almost all guitars buzz to some degree (in my experience) when not touching them, depending on static, amp, and gain levels of you're particular setup. If you want to leave it plugged in and un-touched turn the vol knob down.

check to see if you're pickguard is shielded too.

[Tone_Terrific]

Jumper from the input (output?) jack ground to the strings/bridge and see if the hum diminishes.

[David Collins]

There's nothing wrong with your guitar at all, nothing wrong with the wiring, and nothing that will be solved by shielding. The problems are all at the other end of the cable, most often at the wall outlet itself.

When you touch the strings or controls, the only change you are making is that you are connecting the entire circuit (guitar, pedals, and amp) to a true ground (your body). If it were already connected to a true ground, as it should be by the 3rd prong on your outlet, then there would be no change when you touched the strings. Any effect touching the strings does have on noise can be traced back to this singular problem.

Check the ground on your wall outlets and circuit box, and if that's good then check the ground from the power cord to the chassis of your amp. You can be pretty sure that the source of the problem is somewhere in that area though, and not your guitar.

[Crowder]

Great advice guys, thanks