Help me track down a noise issue

[misterwhizzy]

I picked up my Strat for the first time in a while this weekend and noticed that it's nearly dead quiet through my rig, whereas my Les Paul has a pretty high noise level. The Strat has a JB in the bridge, and even with its volume all the way up, there's very little noise. The Les Paul has a WLH set, and with the volume pot all the way down, it's still got a fairly high noise floor. The amp sounds almost the same with the LP as it does without any cable plugged in.

Does this indicate a shielding issue in the Les Paul? The control cavity is bare wood, and the cover doesn't have any shielding on it either. If not, I need to return the aluminum tape I bought at Home Depot this afternoon.

 

[Mincer]

I'd say it is worth shielding the LP to see if that helps. I've only ever used copper or graphite paint.

 

[ThreeChordWonder]

Could just be a bad bridge or pot ground, but...

Use copper tape from Amazon, a fraction of the price it is at those luthier online stores. The adhesive is electrically conducting, so all you need to do is overlap the edges and make sure it is all grounded somehow.

Worth considering sheathing the wires to the selector switch and the switch cavity and cover as well, also the control cavity and its cover too. If that don't work, break out the cooking foil and wrap the whole guitar. And yourself

 

[Demanic]

I say some sort of grounding issue or cold solder joint. I'd look into those first.

 

[misterwhizzy]

I say some sort of grounding issue or cold solder joint. I'd look into those first.

I plugged a patch cable into the jacks of each and measured the resistance between the sleeve and the bridge. Strat gave me 0.6 ohms, and the LP gave me 0.7 ohms. I think I can rule out a bad ground. I guess I have to do the shielding I really didn’t want to do.

Another clue is that I can make it much less noticeable by turning 90 degrees when I play. I would think that almost certainly points to EMI.

 

[Securb]

I guess I have to do the shielding I really didn’t want to do.

Sounds strange. I have not had to do any shielding in any of my five Gibsons. I have a very long signal chain and I gain stage. Do you run a ground across the tops of all 4 pots?

 

[misterwhizzy]

I do run a ground across all four pots, connecting with three wires to avoid a ground loop.

I went ahead and covered the entire control cavity in aluminum foil tape and notice very little difference. I suppose I’ll just use my noise gate when I play this guitar.

 

[Mincer]

Do you get the same noise with a different cable? Different outlet? Different location altogether?

 

[misterwhizzy]

Do you get the same noise with a different cable? Different outlet? Different location altogether?

I changed out the guitar, leaving everything else exactly the same, and it was nearly inaudible.

 

[Mincer]

Any chance the hot and ground on the jack are swapped?

 

[The Dali]

Been down this road a million times. It is the shielding. Check out my video on the subject.

https://youtu.be/QEG4MS3oJt0


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[solspirit]

Been firm this road a million times. It is the shielding. Check out my video on the subject.

https://youtu.be/QEG4MS3oJt0


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I just can't understand why this isn't done on every guitar.

 

[The Dali]

I just can't understand why this isn't done on every guitar.

The Gibson guitars are along the worst, especially the studios. Just bare wood in the cavity. Every import guitar I’ve seen in the last 10 years have had shielding paint.


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[Securb]

I have two Les Pauls with WHLs and no shielding, and they are dead silent. There is something else going on here.

 

[Mincer]

You can always post some clear pics and we can see if there is anything obvious.

 

[The Dali]

Does the sound/noise go away when you touch the strings?


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[misterwhizzy]

Does the sound/noise go away when you touch the strings?

No, the noise does not go away when I touch the strings. But I can't think of a downside to the shielding. I did shield the control cavity, but that didn't help at all. I still need to check the hot/ground swap like Dave suggested, but if that's not the problem, I guess my next step is to shield the pickup cavities. My question there is how do I connect the sections of foil tape in the cavities to each other and to the control cavity?

 

[Clint 55]

All you can do is make sure your shielding is solid and make sure all the grounding is solid including every component having a ground wire and a ground wire soldered to the bridge. Usually this is the issue except in the rare case that something is really fubar. Soldering a ground wire to the bridge is an important aspect. A lot of time, a ground wire will just be resting under there lightly contacting the bridge and not soldered to it. That plus no shielding can let a lot of noise in.

 

[GuitarDoc]

Is the wire from your switch shielded? If not, I would replace that wire with a good shielded wire. But still, do the copper tape shielding of the pup cavities and control cavity and its cover.

 

[misterwhizzy]

Is the wire from your switch shielded? If not, I would replace that wire with a good shielded wire. But still, do the copper tape shielding of the pup cavities and control cavity and its cover.

Does the tape from each of the pickup cavities need to connect to a common ground and to each other? I guess a necessary first step is taping the cavities, but I'd rather not have to restring multiple times.