[Ax]

I'm gonna redo the wiring on my guitar for two reasons:

I want to clean up my original work, which I believe is causing hum.

Also, I have a ground loop.

So my question to you is this:

If i have a ground wire coming from each pickup (one humbucker with 5 wires and one single coil with 3 wires), should the ground wire from each pickup go to the same spot?

Currently my controls are this:

Single coil has a DP3T switch in On/Off/Phase
Humbucker with DP3T switch in On/Off/Split (which I may switch to On/Off/Phase if I can find a schem for humbucker this way)

Both go to a DPDT Switch that switches from Series/Parallel

Then that goes directly to the output jack.

Currently the ground wires go to the inner lug on the output jack.

Why do I have a ground loop?

Btw, Hipshot Baby Grand bridge... there's nowhere to ground to on it.

[gtrdave]

All of the ground wires should attach together in one way or another, typically on the back of a metal potentiometer case, and then one common ground wire goes to the "sleeve" connection of the output jack (the outer ring, not the protruding point, aka the "tip").

Why do you think that you have a ground loop?

[Ax]

Originally Posted by gtrdave

All of the ground wires should attach together in one way or another, typically on the back of a metal potentiometer case, and then one common ground wire goes to the "sleeve" connection of the output jack (the outer ring, not the protruding point, aka the "tip").

Why do you think that you have a ground loop?

Oscillation whenever the guitar is connected to an amp, goes away when I touch the switches.


No potentiometers on the guitar. At all.

[Major Tom]

Btw, Hipshot Baby Grand bridge... there's nowhere to ground to on it.

Your strings need to be grounded, unless you have EMG or other active pickups; otherwise you're going to have hum / noise issues. With that type of bridge, you don't attach the ground wire to to the bridge itself. A small hole from the control cavity is drilled thru to one of the holes for the bridge's threaded stud inserts. You stick 1" or so of bare wire into the stud insert hole before you install the insert, pull it up and then push the threaded stud insert and the wire in to the hole together. After its put in, the bare wire is jammed in there, between the wall of the hole and the outside of the threaded insert.

Sometimes, after several years, the wire will oxidize, and/or the wood will dry out to where the wire is not making a good enough electrical connection to the insert, and hum will return. At that point, you just pull the insert out and re-do the ground wire.

You may have additional wiring problems, but the first thing I would do is ground the bridge, and then go from there.

[BillSPrestonEsq]

Originally Posted by Major Tom

Your strings need to be grounded, unless you have EMG or other active pickups; otherwise you're going to have hum / noise issues. With that type of bridge, you don't attach the ground wire to to the bridge itself. A small hole from the control cavity is drilled thru to one of the holes for the bridge's threaded stud inserts. You stick 1" or so of bare wire into the stud insert hole before you install the insert, pull it up and then push the threaded stud insert and the wire in to the hole together. After its put in, the bare wire is jammed in there, between the wall of the hole and the outside of the threaded insert.

Sometimes, after several years, the wire will oxidize, and/or the wood will dry out to where the wire is not making a good enough electrical connection to the insert, and hum will return. At that point, you just pull the insert out and re-do the ground wire.

You may have additional wiring problems, but the first thing I would do is ground the bridge, and then go from there.

Agreed, and I actually have found a fairly easy way to ground inside a bushing like that. You can, with a hot enough soldering iron, melt in a small plug that fills the bottom of the bushing and connects to the wire. It does not make a perfect solder joint, but if you do it thouroughly, it is like screwing something in, and the contact occurrs from the sides.
Or you can drill a small hole into the bushing and run the wire into that and solder it directly to the bushing. (That is tricky, but I have succesfully done it.)

[ethan_hanus]

Typically all your grounds go to the volume pot, and from the volume pot go to the bridge so it can be grounded through your body. If you can find a way to ground to the bridge, then all your problems will go away.