Help with wiring circuit board pickups please!

[portablefrank]

Hello everyone

Please can someone more knowledgeable that myself help me with the wiring of a lawsuit Les Paul I've recently picked up.

I'm new here, the pickups aren't SD but I figured this forum would be one of the best places to ask for help - I hope that's okay!

The pickups are copies of Bill Lawrence The Original circuit board pickups from the 70s/80s but these pickups only have a 3 conductor cable and a bare ground (The Originals are 4 and a ground I believe). From what I've read online red/white = north start/finish and green/bare = south start/finish on these pickups but I need to pick up my multimeter from work to check.

A previous owner has wired them up with 3 on//on switches (not on//on//on), I've been advised the middle switch is a phase reversal and the other switches were likely to be intended to be used as coil splitters but because of the way they've been wired you can only switch between the coils and can't use them in true humbucker mode (so I've been told - this could be incorrect).

The back of the pickups looks like this:



This is how they're wired in, all pots are grounded but I haven't included these wires in the diagram:



I like the way the guitar looks with the switches so I'm going to keep them in but would like to confirm if this is indeed wired up incorrectly and if so, how to correct it.

Thanks in advance!

PF

[ThreeChordWonder]

First thing to do is confirm the wiring. Three plus a (bare) ground or three plus a ground plus a bare? It's possible the previous owner combined the ground or fourth wire and the baseplate ground, usually bare, into one at the pickup end. That's not clever because for coil splits and phase flipping you need to keep the two pairs of pickup coil wires and the baseplate ground separate. The baseplate ground should always go to ground separately, or at the very least be grounded onto a pot at the same "downstream" end of the cable.

Next thing to do, IMHO, is to replace the wire with 4 plus a bare pickup wire. The stuff below is 13 bucks for a ten foot length.

Figure out which tab on the pickup connects to which through the pickup coils, then make your best guess at which is the start and which is the finish in each pair.

Bill Lawrence color codes are:

Red = north start
White = north finish
Black = south start
Green = south finish.

SD color codes are:

Black = north start
White = north finish
Green = south start
Red = south finish

It's usually the "finishes" that get joined together at the humbucker (two cores plus a bare ground in the cable likecSeth Lovers), or at the ends of the individual wires, or get routed to a push-pull or switch for coil splitting.

Coil split wiring depends on which coil you want to leave active. The SD default is to select the north or slug coils, but its equally possible to select both south or screw coils or one north and one south so the coil split bridge plus coil split neck remains hum canceling.

As for what wiring is "correct", that entirely depends on what you want to achieve.

Let us know and we'll do our best to help out.



ROSENICE 4-Conductor Shielded Wire Guitar Circuit Wiring Hookup Wire Pickup Cable https://www.amazon.com/dp/B077QP9PZH...SXNVZ9JQFT8JA4

[portablefrank]

Thanks for the response.

It’s definitely 3 wires plus a ground, there’s a few pics of these pickups online and I’ve not seen any in a 4 plus ground configuration.

I suppose “correct” wasn’t the best way to put it, if phase reversal and two coil splits using mini toggles is possible then that’s what I’m aiming for but if my understanding is correct at this point the wiring just switches from one coil to the other so neither pickup works as a humbucker.

I’ll report back once I’ve got a better idea as to what each of the terminals on the back of the pickup are.

In the meantime if anyone knows of these pickups and has any suggestions for wiring please let me know.

Thanks

PF

[ThreeChordWonder]

I think its likely someone has pre-combined two of the wires one would normally expect to come out of the "downstrwam" ends of the pickup cable at the "upstream" end, on the humbucker itself. Most likely it is both "finish" wires. You usually coil split by grounding both of those. The inactive coil becomes grounded at both ends, whilst a new ground is created for the coil that remains active.

The only thing I can suggest is to try playing it and see how it sounds.

You can test which coils are active at any given time by tapping the pole pieces with something metallic. An active coil will give a loud noise. An inactive coil should give no noise but in reality mechanical coupling will cause some noise from the active coil, but it should be a lot less.

If everything's working, the only mods I would suggest would be to make the volume pots independent by (1) swapping the "in" and "out" wires over (leave the third lug grounded) and (2) making sure there is no direct ground between the volume pots. I would also fit treble bleeds if you go for independent volumes.

[ThreeChordWonder]

PS check the ohms - red to white red to green and green to red, then all of them to bare.

I hope you don't get a circuit between any if them and bare, because that could cause problems.

With the others, one combination should give you around twice the ohms of two others. That will be the pairing from the full humbucker, both coils end to end. The other two will the coil splits, as you're tapping the single wire that has been used to join the humbucker's coil to coil wires on the humbucker itself. You use that wire for the coil splits.

[ArtieToo]

It would also be helpful if you'd take the camera back a bit, and reshoot that first pic so that we could see the left side of the bottom. I'm pretty sure I know how it goes, but a pics worth a 1000 words.

[ThreeChordWonder]

I'm looking at the photo.

It looks like there's a fourth coated wire (blue-ish) soldered to contact #4 (bottom left) on the pickup.

It also looks like the baseplate ground (looks black in the picture) goes through a little hole to the left of contact #4.

[portablefrank]

Thanks ThreeChordWonder, just in case it's of any relevance I've just tested the pickups with a multimeter.


The red lines indicate continuity.

Measuring between 1 (red) and 3 (white) - 8.09 (neck) / 8.25 (bridge)

Measuring between 2 (green) and 3 (white) - 4.13 (neck) / 4.13 (bridge)

Measuring between 1 (red) and 2 (green) - 3.95 (neck) / 4.10 (bridge)

I'm in the process of refinishing the guitar these were ripped from so I won't be able to wire it up to test for a while.

Thanks

PF

[portablefrank]

I'm looking at the photo.

It looks like there's a fourth coated wire (blue-ish) soldered to contact #4 (bottom left) on the pickup.

It also looks like the baseplate ground (looks black in the picture) goes through a little hole to the left of contact #4.

I think you're looking at a the grey wire running to the pickup selector switch?

[portablefrank]

It would also be helpful if you'd take the camera back a bit, and reshoot that first pic so that we could see the left side of the bottom. I'm pretty sure I know how it goes, but a pics worth a 1000 words.

Hi ArtieToo

Yeah in hindsight that wasn't the best pic, this one is a better:


It's not clear from but the bare is soldered to E2 underneath the brown wire, I assume E stands for earth.

Thanks

PF

[portablefrank]

PS check the ohms - red to white red to green and green to red, then all of them to bare.

I hope you don't get a circuit between any if them and bare, because that could cause problems.

With the others, one combination should give you around twice the ohms of two others. That will be the pairing from the full humbucker, both coils end to end. The other two will the coil splits, as you're tapping the single wire that has been used to join the humbucker's coil to coil wires on the humbucker itself. You use that wire for the coil splits.

I typed the response above before I saw this comment, there's no continuity between any of the contacts to E1/E2 except for themselves.

So does that mean the existing wiring is correct?

Thanks

PF

[ArtieToo]

Here's the translation to Duncan color. (But with a slight polarity "maybe".)

[ArtieToo]

The black and green are reversible. The only way to translate them directly to Duncan black/green would be to put your meter on "volts", and connect your red lead to "red", and your black lead to "white." Bring a screwdriver up against a coil, and then yank it away. If it goes positive, then your red lead is Duncan's green wire. If the meter goes negative, then the red lead is Duncan's black wire.

Either way, your current red and white is hot and ground, and your green is the "split" wire. (To go single coil mode.)

When I say "hot & ground", I mean the pickups + and -. Absolute ground is the wire connected to E1.

Also, when I editted that pick, the black and green lines should go to the inside solder pads.

[portablefrank]

Thanks ArtieToo, I've just tested and red to red makes it jump negative so red = black.

Does that mean I was previously given bad advice and two of the on//on switches split the humbuckers and the third on//on reverses the phases on the bridge pickup (please see the diagram in my original post)?

The wiring is a complete rats nest and I'm new to these mods so I didn't know where to begin!

The help from both of you is greatly appreciated!

PF