Pickup signal leak. Please, help...

[Mikus]

Hi! I have a problem with my wiring. I've modified my Polish-made Les Paul style guitar. I shielded it with a copper tape. I replaced stock pickups with vintage type Entwistle HV58 humbuckers and wired it the Jimmy Page's way. I used four Bourns push-pull pots, Switchcraft jack and Japanese Boston 3-way toggle switch. I used wiring diagram from Seymour Duncan: https://docs.google.com/gview?embedded=true&url=http%3A%2F%2Fwww.seymourduncan.com%2Fwp-content%2Fuploads%2F2016%2F05%2FJP_wiring.pdf, except I have connected all the grouds to a single point. The issue I have is some signal leak from both pickups. When I select bridge only on my 3-way switch and turn the bridge volume to 0 I can still hear neck pickup unless I turn neck volume to 0. The reverse is also true although signal leaking from bridge pickup is much fainter. I checked my wiring countless times, isolated my signal cables. I thought that problem might be with the toggle switch or four conductor cable running to it, so I have tried connecting both volume pots (one at the time, of course) straight to the jack hot output. It didn't change a thing. Have someone else experienced this strange issue? I would very much appreciate any help or hint that could bring me closer to solving this annoying problem. I also enclose some photos of my cavity. Greetings from Central Europe!

 

[beaubrummels]

Re: Pickup signal leak. Please, help...

That Duncan drawing is pretty messed up. The bridge volume isn't even connected to a pickup. The neck volume is wired backwards. And the bridge green is connected to the neck green and nothing else.

I hate to say it, but I think you need a different drawing and start over.

 

[Mikus]

Re: Pickup signal leak. Please, help...

Are you sure? I think the bridge green is connected to the ground when the bridge tone push-pull is in down position. Same thing with neck green and neck tone push-pull. What do you mean that the neck volume is wired backwards?

 

[Artie]

Re: Pickup signal leak. Please, help...

The bridge volume isn't even connected to a pickup. The neck volume is wired backwards. And the bridge green is connected to the neck green and nothing else.

Hey beau; Not sure how you're reading that diagram, but none of those three things is true. I've highlighted the bridge path in blue, and both pickup ground paths in red. (Sloppy highlighting because I'm using my laptop with lousy mouse control.)



That diagram is fine.

 

[Mikus]

Re: Pickup signal leak. Please, help...

Thank you for your kind replies. I also thought that the diagram was ok. This brings me to the conclusion that I must have messed up something. But everything works as it should, except for that signal leak from both pickups. I've checked things with multimeter a few times and it also shows the guitar is wired correctly. I have been scratching my head for over a week right now, and have some strange ideas. ;-) Is it possible that the signal from pickups exists as a current in the ground? Or some cable works as antenna and picks up the electromagnetic field of humbuckers? Or maybe series/paralell switch bleeds some signal through internal contacts (but that should only cause the bridge pickup signal leak, if I think correctly)? I'm (dazed and) confused...

 

[Artie]

Re: Pickup signal leak. Please, help...

This is a tough one to diagnose from afar. One of the primary causes of a symptom like this is the pots not going to completely "zero" when turned down all the way. I've seen it happen before. The only way to check it is with a decent meter.

 

[Mikus]

Re: Pickup signal leak. Please, help...

This is a tough one to diagnose from afar. One of the primary causes of a symptom like this is the pots not going to completely "zero" when turned down all the way. I've seen it happen before. The only way to check it is with a decent meter.

Well, when I turn down both volume pots, the guitar is completly silent. These are brand new Bourns pots, and should be of a decent quality. When checking it with a multimeter, what should I look for?

 

[beaubrummels]

Re: Pickup signal leak. Please, help...

Hey beau; Not sure how you're reading that diagram, but none of those three things is true. I've highlighted the bridge path in blue, and both pickup ground paths in red. (Sloppy highlighting because I'm using my laptop with lousy mouse control.)

View attachment 78714

That diagram is fine.

Ok, my mistake my bad. Thanks for that. For a start, don't know why (late PM/early AM dyslexia?), but I was reading the switch positions opposite, and I wasn't expecting to see an 'independent volumes' mod, coupled with hitting the tone pots first before the volume pot (I've never seen wiring like that in a drawing). I've drawn about 14 different variations on a Jimmy Page wiring diagram, about half I physically tested and all tested good with actual test wires, but none of them looked like this drawing. So there you go - learn something new.

 

[Mikus]

Re: Pickup signal leak. Please, help...

Hello again! Maybe some of you remember that after consideration I have decided to rewire the guitar according to the new diagram that added blower switch instead of series switch.



After rewiring the guitar with new cables the problem was still there, although this time my soldering/cable work was much cleaner (I took my time). The neck pickup was still audible on treble channel and bridge pickup signal was leaking to rhythm channel. I came to the conclusion that with 99% certainty the leakage wasn't effect of my wiring mistake, but was due to some malfunctioning part(s) (probably potentiometers). I wasn't very happy with perspective of rewiring my guitar over and over again substituting every part imaginable, so I came up with this idea:



This is modified 3-way toggle switch. Standard switch has four plates. Middle plates are connected to the jack output and outer ones are connected to pickups (vol pots). As you can see I have installed two additional plates (middle ones from my old 3-way toggle). I have connected their lugs to the ground. Now, when pickup is not selected on the switch, it's signal is not only disconnected from middle plates but also connected to the ground. With this mod my bridge and neck channels are 100% free of other pickup's interference (whatever was it's cause) I share my experience here with anyone who encounters that problem. You can use my solution, free of charge. Just drink some vodka to my health! ;-)

 

[AlexR]

Re: Pickup signal leak. Please, help...

That sounds like there was something up with the switch wiring......or issues with the way the thing was sitting once in the guitar.

 

[Mikus]

Re: Pickup signal leak. Please, help...

That sounds like there was something up with the switch wiring......or issues with the way the thing was sitting once in the guitar.

The switch itself was not the source of the problem. As discussed above, to check it, I've made modifications to the circuit that completely omitted the switch and 4-conductor cable running to it, and the problem was still there. Interestingly, activating a blower switch was fixing the leak. There was something going wrong between the place where wires from pickups connected to the pots and the place where they where leaving them. I've shown it to the guy who is not a guitar tech, but is an electrical engineer and manufacturer of transformers for audio applications, that used to play guitar in his younger years. He looked at it for about an hour and said that he could see no problem with my wiring and suggested trying some new pots. Well, as curious as I am of what was the source of the problem, I couldn't bring myself to buy new pots and rewire my guitar for a fourth time in two months. So I came up with that switch above... I'm happy with it, at least for a time being.

 

[Zanymus]

Re: Pickup signal leak. Please, help...

Hi Markus!

After you fixed the issue by hacking the switch, did you ever revisit the problem?

Here's the thing: using the same diagram, I wired up two different guitars, with two different sets of pick-ups and two different sets of four push-pull potties, and I systematically and consistently experienced the exact same signal leakage problem from each pick-up into the other, on both guitars. It's definitely a bug (or feature?) of the diagram itself.

Note that:

(1) the diagram obviously misses the direct connection between the earth soldering blobs on the back of each pottie, but that's a no-brainer (and if the cavity is covered in shielding paint or foil, it may be superfluous anyway);

(2) when in series mode, the selector on trebble produces almost no signal, but that seems to be by design so no worries there (by contrast, in middle and rhythm positions, the multimeter shows an output equivalent to the sum of the two humbuckers in series, which is nominal and correct);

(3) also when in series mode, the bridge tone pot (supposed to have no effect) actually behaves like the bridge pick-up's volume pot, while the actual bridge volume pot has no effect indeed.

My guess is that for some reason it is the wiring of the neck tone pot's push-pull switch which somehow mixes a fraction of the signal from both pick-ups into the overall output. I'm still experimenting to figure out how this could be resolved.

If I don't succeed, I will use your switch hack. Could you perhaps post a close-up picture of the actual modded selector switch as wired up? I don't quite understand how you ground each side only when that side is off, without ending up grounding both in all positions (and thereby muting the guitar altogether). Thanks!

 

[Dave Locher]

Re: Pickup signal leak. Please, help...

That switch modification is brilliant!
The problem exists because of the way the volume pots are wired. Pickup hot to center lug gives that signal bleed. I have no idea why.

I only know this because I built a guitar that way a couple years ago with otherwise very conventional wiring (no coil splits, no phase switching, just two pickups, two volume pots, one tone pot, and a three-way switch).
At first I loved being able to turn the neck pickup all the way up or down without killing the sound in the middle position. Then I noticed the sound bleed you mention. Swapped the volume pot wires (pickup hot to outer lug, volume out from center lug) and fixed the problem.

 

[Zanymus]

Re: Pickup signal leak. Please, help...

Thanks mate, that sure as hell solved the issue on both guitars. So simple!

 

[NegativeEase]

Re: Pickup signal leak. Please, help...

usually pickup cross talk is wipers or contacts in switching.

 

[Zanymus]

Re: Pickup signal leak. Please, help...

Ok, so here are the original AllParts and SD wiring diagrams, and their respective mods with the inverted connections on the volume pots. The modded versions below don't have any signal leakage, but for both of them in series mode, selecting the bridge pick-up only actually mutes the guitar (kill switch):

 

[rango]

Re: Pickup signal leak. Please, help...

Hi guys. I am wiring my guitar right now so correct and working wiring diagram is this picture correct?

That picture works without switch mod correct?

Also the green wire is coil splitting wire correct?

red is positive, black is ground and silver wire pictured is pickup shield ground ?

Is Jimmy Page wiring 50s style or modern style type?

 

[beaubrummels]

Re: Pickup signal leak. Please, help...

Hi guys. I am wiring my guitar right now so correct and working wiring diagram is this picture correct?

That picture works without switch mod correct?

Also the green wire is coil splitting wire correct?

red is positive, black is ground and silver wire pictured is pickup shield ground ?

Is Jimmy Page wiring 50s style or modern style type?

View attachment 101529

Don’t know what you mean by “switch mod.”

On Duncan pickups, the wire colors are documented here:
https://www.seymourduncan.com/blog/the-tone-garage/humbucker-wire-color-translation

That JP drawing is not a Duncan-produced drawing and it seems to be missing the white wires.

Jimmy Page wiring should be 50’s tone wiring. That drawing is Modern tone wiring.

 

[rango]

Re: Pickup signal leak. Please, help...

This thread says that original Seymour Duncan drawing DID NOT work as it leaks signal and the last drawing says: "No signal leakage across pickups" so did anyone @Zanymus @Mikus wire it and did it work according to last drawing?

My pickups have 4 wires also, not 5. Black (ground), Red (signal/positive), Bare(copper/pickup ground) and white which is coil splitter wire. I'm assuming green in the drawing above is also coil splitter wire? , hence those two green/white could be interchangeable for coil splitting purposes?

In different drawing (below) i see green and white being joined together like here so i'm assuming 1 or 2 wires don't matter since they're joined

I want to make sure before i rewire and do extensive soldering that the wiring works?

I also have signal leakage currently but i have it wired with 50s wiring without any push/pull pots. Just standard CTS pots. Since I don't wanna trace this i decided just to upgrade the pots to Bourns push pull and rewire for JP style. It's $20 mod for me. I'm aware that drawing below is for CTS not Bourns but i wanted to point out that green and white are joined together so 4 or 5 wires does it matter? I just want to make sure that this Green wire in last picture diagram posted is in fact coil splitting wire?

Any help is greatly appreciated guys. Thank you.

https://www.sixstringsupplies.co.uk/cts-push-pull-pot-wiring