Ground noise

[brianhj]

I get ground buzzing and when i touch the pole pieces on the pickups it gets louder. Same old story. Here's the diagram i'm using, very simple setup:
https://docs.google.com/gview?embedd...H_2S_5W_1V.pdf

Cavity is shielded using shielding tape. Right now i it's just guitar body, no neck, no strings. I checked continuity between the output jack tip and the pole pieces and it's connected, so the jack is wired correctly.I triple checked connections with the diagram. Any ideas?

[Clint 55]

Re: Ground noise

Things that I've tried that seem to help lower noise are getting a ground wire soldered to the bridge. Also solder a ground wire to a screw mounted in the body. Having a ground wire connected to the shield tape also helps, but the down side to that is it will kill your signal if your pickguard isn't super tidy and a hot wire makes contact with the shielding. It helps to have each electronic part grounded by a wire as well which people don't do for some reason. Run ground wires to the blade and mini toggles.

[Johnny the Kid]

Re: Ground noise

Well pics would definitely help in finding what's wrong.

[brianhj]

Re: Ground noise

Well pics would definitely help in finding what's wrong.

Ain't much to see but here ya go

[Clint 55]

Re: Ground noise

So on the back of the pot I see the left blob is your single coils grounded, middle blob looks like the lug and the humbucker, and if your guitar works the right blob must be to the jack. That ain't enough. You have to solder additional ground wires to the switch, the bridge, and the body, as well as fully shield your pickguard and cavity.

[Coma]

Re: Ground noise

That's a bummer, man. I had that happen to a guitar with high output pups once. Swapped the pups, swapped all the electronics, still wouldn't go away. Poor axe has been living in her case since then.

[brianhj]

Re: Ground noise

So on the back of the pot I see the left blob is your single coils grounded, middle blob looks like the lug and the humbucker, and if your guitar works the right blob must be to the jack. That ain't enough. You have to solder additional ground wires to the switch, the bridge, and the body, as well as fully shield your pickguard and cavity.

What does the switch and the bridge and the body have to do with this? Shouldn't I be able to connect a humbucker directly to an output jack and it should be silent? I'm touching the pole pieces and it buzzes so i don't see how grounding the switch and bridge would accomplish anything... the bridge isn't even connected to the circuit right now. The switch is already grounded by that shielding foil on the pickguard anyway. I tested continuity

Seymour Duncan support once had me connect a humbucker directly to an output jack and plug it in, humbucker buzzed. I sent the humbucker in they inspected and said it's fine. I never got a resolution. I fear it's the same case here

[Johnny the Kid]

Re: Ground noise

What does the switch and the bridge and the body have to do with this? Shouldn't I be able to connect a humbucker directly to an output jack and it should be silent? I'm touching the pole pieces and it buzzes so i don't see how grounding the switch and bridge would accomplish anything... the bridge isn't even connected to the circuit right now. The switch is already grounded by that shielding foil on the pickguard anyway. I tested continuity

Seymour Duncan support once had me connect a humbucker directly to an output jack and plug it in, humbucker buzzed. I sent the humbucker in they inspected and said it's fine. I never got a resolution. I fear it's the same case here

Humbuckers get rid of 60 cycle hum, not all hum. The noise you're hearing is ground noise. In order to get rid of that you have to ground your pickups to the bridge and strings.

[brianhj]

Re: Ground noise

Humbuckers get rid of 60 cycle hum, not all hum. The noise you're hearing is ground noise. In order to get rid of that you have to ground your pickups to the bridge and strings.

Once again the strings aren't even on the guitar, it's just the body. The bridge isn't even connected to anything it's out of the circuit - it's just extra metal near the circuit but not connected to it. I don't see how something unpowered and external to the circuit could create ground noise

In fact how about I remove the bridge and claw and tremolo springs from the guitar body completely?

[Clint 55]

Re: Ground noise

https://en.m.wikipedia.org/wiki/Chassis_ground

[brianhj]

Re: Ground noise

https://en.m.wikipedia.org/wiki/Chassis_ground

Yes that's great but how does that apply here?

What if I remove the humbucker from the setup and connect it directly to an output jack to an amp? Would you still say it needed a chassis ground if there was no chassis?? Should I expect ground noise in that case?

[Clint 55]

Re: Ground noise

The system naturally picks up noise. Humbuckers cancel some but not all of the noise. To minimize it you have to shield the cavity and pickguard to prevent some interference from getting picked up. Then allow the remaining noise to dissipate by having all the electrical components connected to the earth ground from the jack and the chassis ground of the bridge and body.

[brianhj]

Re: Ground noise

The system naturally picks up noise. Humbuckers cancel some but not all of the noise. To minimize it you have to shield the cavity and pickguard to prevent some interference from getting picked up. Then allow the remaining noise to dissipate by having all the electrical components connected to the earth ground from the jack and the chassis ground of the bridge and body.

Like i said i shielded the cavity and the bridge isn't even in the equation since there are no strings. I doubt having a hunk of metal near the pickups would cause the pickups to buzz when i touch them. Sounds more like the pickups aren't grounded properly? I don't know

Also, should i expect to have ground noise if i directly connected a humbucker to output jack? If i have the same symptoms then everything is out of the equation except pickup, jack and wires


Anyone know what the symptoms are of having the signal and gnd reversed at the jack?

[Clint 55]

Re: Ground noise

A humbucker directly to the jack will be more quiet than a huge circuit yes.

I'm looking at the picture of your unshielded pickguard.

The purpose of a ground wire soldered to a screw mounted in the body and to the bridge is to allow more places for the noise to dissipate. You also need to run a ground wire to the switch instead of relying on it making contact with the foil.

[brianhj]

Re: Ground noise

The pickguard is shielded lol, that's what the foil is

The switch a nd pots mechanically secured to the foil is more reliable in my opinion