Ground noise

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brianhj

New member
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?embedded=true&url=http%3A%2F%2Fwww.seymourduncan.com%2Fwp-content%2Fuploads%2F2016%2F05%2F1SCH_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?
 
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.
 
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.
 
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.
 
Re: Ground noise

Clint 55 said:
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.
Click to expand...

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
 
Re: Ground noise

brianhj said:
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
Click to expand...

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.
 
Re: Ground noise

Johnny the Kid said:
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.
Click to expand...

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?
 
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.
 
Re: Ground noise

Clint 55 said:
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.
Click to expand...

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?
 
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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.
 
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
 
Re: Ground noise

The LP was quieter because the toggle was grounded and the bridge was probably connected to the ground. You don't have that here.

Your shet isn't broken. I'm aware of the tiny piece of foil that you think is sufficient by virtue of its loose mechanical connection.

Again, you have to be as thorough as possible if you want to minimize noise. Shield the rest of your pickguard to prevent interference. Ground all your electrical components with a wire, in this case only your switch is missing. Build a chassis ground for the noise from the electronics to dissipate by soldering a wire to the bridge and a screw mounted in the body.
 
Re: Ground noise

Put foil tape on the rest of the pickguard? Do you solder the tape together? Because I wouldn't rely on foil tape joined by adhesive - doesn't sound like a good electrical connection. Just making sure

Also, my mechanical connections aren't "loose" - they're as tight as the battery connection in your car
 
Re: Ground noise

Again the gibson had zero shielding i don't get why it's so important here. If i run a ground wire from the pot to the bridge and to the switch should the noise go and i can forget shielding?

I never claimed my "shet" is broken btw, I just don't get how double grounding the 5way is going to stop a buzz when i touch a humbucker but i'll try it
 
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Re: Ground noise

Humbuckers can be good without shielding because the pickup itself is hum cancelling and also the wires are shielded. Also, toggles get grounded with a wire but for some stupid reason, people are racist against the switch and think it doesn't need it.

In your case, getting your chassis ground going will probably have the most effect. That means the noise from the electronics dissipates through them. Not that the body and bridge are producing noise that needs to be grounded out.

Next significant is improving the ground connection to the switch by running a wire to the base.

Last important would be shielding the rest of the pickguard, but it never hurts to be thorough.

Also yas, having hella continuity between the tape and even a wire to it can possibly be more effective, but I usually just slam the tape in and that seems to work.
 
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