P-Rail Les Paul wiring question

[Galva]

Hello everyone, this is my first post in this forum and I have a question regarding P-rails.
I am planning to install a set of them in a Les Paul with 2 volume and 2 tone knobs and a 3-way toggle switch.

I have found the wiring diagram below on the Seymour Duncan website and there are two push/pull potentiometers in the tone position, which can change the pickups from humbuckers to p90’s and single coils.

I am fairly new to guitar wiring, I have only wired a set of Black Winters into an Epi LP without any coil splitting and switched all the electronics but that's it.
The thing is that I don’t know whether the additional six contacts on a push/pull potentiometer are somehow connected to the rest of the pot.
Would it be possible to put the push/pull pots in the Volume position of the Les Paul guitar and just connect all the respective wires there or would it be necessary to adapt the whole diagram in order to make the volume pots the ones with the push/pull functionality?

Thank you very much for your help
Galva

 

[Artie]

Re: P-Rail Les Paul wiring question

The switch on a push-pull pot is completely electrically independent of the pot. It's attached mechanically simply as a convenience. You can have that switch anywhere, even as a separate DPDT toggle.

And welcome to the forum.

Artie

 

[Galva]

Re: P-Rail Les Paul wiring question

Alright I understand, thank you for your explanation

But I have another question, please excuse my ignorance.

In the diagram, why is one leg bent onto the housing for the volume pots but not for the tone pots? (The blue arrows)
And does the connection from the tone pot to the volume pot and to the push/pull switch part create a common ground? I do not see a connection to the rest of the ground loop.

Thank you very much
Galva

 

[Chistopher]

Re: P-Rail Les Paul wiring question

Alright I understand, thank you for your explanation

But I have another question, please excuse my ignorance.

In the diagram, why is one leg bent onto the housing for the volume pots but not for the tone pots? (The blue arrows)
And does the connection from the tone pot to the volume pot and to the push/pull switch part create a common ground? I do not see a connection to the rest of the ground loop.

Thank you very much
Galva

View attachment 86219

Soldering the third lug on the volume pots is essentially the same as soldering it to the back. This is because the volume essentially splits the path of the signal. At 50% (on a linear taper pot) volume half the signal is going to the middle lug to the output and half is going to the third lug, to the ground. On the tone pot at 50% half of the signal is going through the middle lug through the cap to ground. That means that half the treble frequencies are being shunted to the ground. At the same time the other half of the signal is trying to go through the third lug, but it can't because that lug doesn't go any where.

In essence, the volume divides the signal between the output and ground. The tone control fades the capacitor in and out of the circuit. I can bust out the electrical engineering terms if you want me to.

As for the "ground loop" you are referring to, that is a common misuse of a term that doesn't actually apply to guitar circuits. So long as all pots and metal parts of the guitar have a ground wire connected to them, you will be fine. It doesn't matter if you do it in a star pattern or just an ugly line. The main things to remember are that all metal parts of the guitar must be in some way electrically connected to the sleeve of the output jack.

 

[GuitarDoc]

Re: P-Rail Les Paul wiring question

You could keep it much simpler (to wire and to play) if you mount the two P-Rails in Triple Shot mounting rings.

 

[Galva]

Re: P-Rail Les Paul wiring question

Thank you Chistopher for your explanation, it helped quite a bit

Regarding the Triple Shot rings,I have found the wiring diagram below, would the phase and parallel switch function still work when P-Rails are used instead of "regular" humbuckers?

Thank you all very much
Galva

 

[GuitarDoc]

Re: P-Rail Les Paul wiring question

Thank you Chistopher for your explanation, it helped quite a bit

Regarding the Triple Shot rings,I have found the wiring diagram below, would the phase and parallel switch function still work when P-Rails are used instead of "regular" humbuckers?

Thank you all very much
Galva


View attachment 86226

Yes. P-Rails function just like any other double coil humbucker pup.

 

[Galva]

Re: P-Rail Les Paul wiring question

I have finally finished the wiring according to the diagram below, including the triple shots and the P-Rails.

The problem is that I do not really know how the triple shots affect the P-Rails, I mean I know the four possibilites per pickup but I do not know the necessary switch positions, could anyone please tell me which switches result in which configuration?

Thank you very much
Galva

 

[Mincer]

Re: P-Rail Les Paul wiring question

The beginning of this video sort of explains how it works.

 

[Imtxn]

Hello,
How is the shield in the triple shot ring connected in a 2-pickup guitar with 2/ volumn & 2/ tone controls using a 4/way switch to select phasing

 

[Chistopher]

The shield of your guitar should be connected to the back of the volume pot. It should make no contact with the triple shot

 

[Imtxn]

Hi Christopher, thanks for responding! I have a confession, my post was misleading because of a typo. I have wired my HH Ibanez with p-rails and triple-shots & a 4-way, not a 3-way.
sorry!
AND, not finding a compatible ckt. On the net, I modded the one I found. By exchanging the positions of the controls & 4-way so that the controls feed the switch & its output connects directly to the jack’s tip.
My issue is each pickup & its controls is isolated from each other before the 4-way, but each volume needs to be on if I want an output from the switch when a single pickup is selected. I used Rh-178 to shield from the volumes to the jack.
may I have your thoughts?
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