Converting a humbucker to RWRP?

[sumitagarwal]

I'm trying to adapt this P-Rails wiring diagram for use with normal humbuckers: https://www.seymourduncan.com/wp-content/uploads/2016/05/2PRail_3G_1VppSPL_1TppSPL.pdf

I know a set of normal humbuckers won't give the same authenticity as P-Rails, but I think with a hot pair it'll give a huge number of good tones:


Here's the problem: to allow hum-cancelling use of the two P90 or two rails together, SD builds the P-Rails Neck as RWRP.

So how would I change my neck humbucker to RWRP to suit this wiring diagram?

 

[Chistopher]

Re: Converting a humbucker to RWRP?

Switch the black and green wires and reverse the direction of both magnets in the P-Rails.

 

[gregory]

Re: Converting a humbucker to RWRP?

Almost but no cigar.

For the wiring you have to combine black and green, connect red to bare/ground and use white as the hot wire.

 

[sumitagarwal]

Re: Converting a humbucker to RWRP?

Almost but no cigar.

For the wiring you have to combine black and green, connect red to bare/ground and use white as the hot wire.

Thanks! That's it? I don't need to flip a magnet or rotate a pickup or anything?

 

[gregory]

Re: Converting a humbucker to RWRP?

You have to flip a magnet still. Either will do, but I'd do I with the one with the wires you reversed. That way one still remains stock in case you want to use it again. Maybe put a sticker or mark the other one to let you know that it's been modified.

But now I've just remembered you're doing this with DiMarzios, correct?

If so then the wire colors will be different. With DiMarzios that have the same poles and wind for each coil (or very similar wind; measure the DCR of each coil), you can just as easily rotate them without having to flip a magnet. But you'll still need to change the wiring so you split to the correct coil per the scheme you want. You won't have to reverse the phase, but you will have to reverse the wiring order of the coils.

Hopefully that isn't too much to digest. It will be easier for me to tell you the colors rather than use generalities.

As far as tone with your DiMarzios compared to P-Rails are concerned, no, you won't get anywhere near as good of a P-90 sound, but you absolutely will get a better tone splitting to a single coil with an EvoN or TZ than you will to the paltry, narrowly-focused rail, IMO and YMMV.

 

[sumitagarwal]

Re: Converting a humbucker to RWRP?

You have to flip a magnet still. Either will do, but I'd do I with the one with the wires you reversed. That way one still remains stock in case you want to use it again. Maybe put a sticker or mark the other one to let you know that it's been modified.

But now I've just remembered you're doing this with DiMarzios, correct?

If so then the wire colors will be different. With DiMarzios that have the same poles and wind for each coil (or very similar wind; measure the DCR of each coil), you can just as easily rotate them without having to flip a magnet. But you'll still need to change the wiring so you split to the correct coil per the scheme you want. You won't have to reverse the phase, but you will have to reverse the wiring order of the coils.

Hopefully that isn't too much to digest. It will be easier for me to tell you the colors rather than use generalities.

As far as tone with your DiMarzios compared to P-Rails are concerned, no, you won't get anywhere near as good of a P-90 sound, but you absolutely will get a better tone splitting to a single coil with an EvoN or TZ than you will to the paltry, narrowly-focused rail, IMO and YMMV.

You're correct! Thanks for remembering I'm using DiMarzio's. With regard to spinning the pickup around, that has nothing to do with DiMarzio vs SD, right? Rather that's because its a "regular" humbucker instead of a P-Rail?

I thought I'd ask + receive advice in SD colors, and that I could later translate the colors myself. But, I'm still worried I could end up making a mistake.

I'd definitely prefer rotating pickup versus flipping a magnet, given the option. Its an Evo Neck that I'd be doing that to, FWIW.

 

[gregory]

Re: Converting a humbucker to RWRP?

If the EvoN has the same or almost the same DCR for each coil the yes you can rotate it and reverse the coil order instead of flipping the magnet. If the DCRs are drastically different then one coil may not sound as good split as the other, though the inductance of each coil is more important than the DCR. I don't have the measurements for either so I can't help with that.

I have more I'd like to say but I have to cut it short for now.

 

[sumitagarwal]

Re: Converting a humbucker to RWRP?

If the EvoN has the same or almost the same DCR for each coil the yes you can rotate it and reverse the coil order instead of flipping the magnet. If the DCRs are drastically different then one coil may not sound as good split as the other, though the inductance of each coil is more important than the DCR. I don't have the measurements for either so I can't help with that.

I have more I'd like to say but I have to cut it short for now.

I appreciate the help.

The EvoN is one of the pickups that uses the same pole pieces for both coils, so at least there's that. It is a "dual resonance" model, so there will be some variation. But part of the beauty of this control scheme is it gives individual access to each coil when you're not in the middle position.

I tried to find measurements of each coil but no dice. Seems the DiMarzio crowd is less interested in those kinds of details than what you see around here?

 

[gregory]

Re: Converting a humbucker to RWRP?

A DMM is a good thing to have for various reasons. In this case you'd be able to find out. One that does inductance can be had for not a lot of money either.

But you're right, this wiring scheme can do a lot of things. And it will answer the question about whether one split coil is better than the other. What's missing that might be worthwhile is the ability to combine one pickup wired in series with one wired in parallel.

I had a scheme that did series/parallel on either pickup and instead of both pickups in parallel combined in parallel (4 parallel coils, not a fan) it would instead split to the inside coils. All the available options were hum-canceling. It didn't do the outer coil thing which I also don't particularly like. What I may have liked better would have been the ability to split the neck to the outer coil instead of running it in parallel (perhaps just when the neck was by itself, otherwise keep the same behavior when both pickups were selelected as described earlier). While it only used two push pulls it also needed a multi-pole 3-way. Anyway, I just wanted to share, FWIW.

 

[sumitagarwal]

Re: Converting a humbucker to RWRP?

A DMM is a good thing to have for various reasons. In this case you'd be able to find out. One that does inductance can be had for not a lot of money either.

But you're right, this wiring scheme can do a lot of things. And it will answer the question about whether one split coil is better than the other. What's missing that might be worthwhile is the ability to combine one pickup wired in series with one wired in parallel.

I had a scheme that did series/parallel on either pickup and instead of both pickups in parallel combined in parallel (4 parallel coils, not a fan) it would instead split to the inside coils. All the available options were hum-canceling. It didn't do the outer coil thing which I also don't particularly like. What I may have liked better would have been the ability to split the neck to the outer coil instead of running it in parallel (perhaps just when the neck was by itself, otherwise keep the same behavior when both pickups were selelected as described earlier). While it only used two push pulls it also needed a multi-pole 3-way. Anyway, I just wanted to share, FWIW.

Yup, I've generally found I'm not a fan of too many coils going at once (I doubt I'll make use of the all-4 parallel mode). I also have found I don't usually like: discrete pickups in series with each other, pickups out-of-phase with each other, or combining pickups that each have different wiring (i.e. a series pickup with parallel pickup, though this may have more to do with having so many coils on). So I feel like this wiring could be pretty perfect for me. Personally, the single-coil outer coils middle mode is a selling point, for that wide Tele-style jangle.

Anyways, to summarize your directions I should:

1) Modify existing P-Rail diagram: For the wiring you have to combine black and green, connect red to bare/ground and use white as the hot wire. **on the neck pickup only, right?**
2) Convert modified diagram to DiMarzio colors
3) Rotate neck pickup 180 degrees
4) Wire it up

 

[gregory]

Re: Converting a humbucker to RWRP?

1) Modify existing P-Rail diagram: For the wiring you have to combine black and green, connect red to bare/ground and use white as the hot wire. **on the neck pickup only, right?**
2) Convert modified diagram to DiMarzio colors
3) Rotate neck pickup 180 degrees
4) Wire it up

Those wiring colors are if you flip a magnet.

If you rotate the neck you want the wire colors for the neck to be like this:

• combine black and green
• connect *white* to bare/ground
• use *red* as the hot wire

They will need to be translated to DiMarzio colors, of course.

 

[sumitagarwal]

Re: Converting a humbucker to RWRP?

Those wiring colors are if you flip a magnet.

If you rotate the neck you want the wire colors for the neck to be like this:

• combine black and green
• connect *white* to bare/ground
• use *red* as the hot wire

They will need to be translated to DiMarzio colors, of course.

Hey Gregory, I'm currently working up the diagram for this and I'm a little confused about your instruction to "combine black and green" (instead of the usual red and white) because, well, they're not combined in the original diagram.

I get that now red should sub for black, and white should sub for green. But for the remaining two of black and green, which should sub for red and which should sub for white?

 

[gregory]

Re: Converting a humbucker to RWRP?

I realized that as I went to bed: some are in parallel. Silly of me.

Duncan colors: black becomes red, red becomes black; white becomes green, green becomes white.

 

[sumitagarwal]

Re: Converting a humbucker to RWRP?

I realized that as I went to bed: some are in parallel. Silly of me.

Duncan colors: black becomes red, red becomes black; white becomes green, green becomes white.

Awesome! Documenting this first in Duncan colors. I'm hoping it may end up useful to somebody else too

 

[gregory]

Re: Converting a humbucker to RWRP?

DiMarzio would be swapping red and white, and swapping green and black. I should remember this since my current project is with DiMarzios also.

 

[sumitagarwal]

Re: Converting a humbucker to RWRP?

Alright, here's my quick-n-dirty version, in SD colors. If this is right I don't think I'll need to also do a DiMarzio version, should be simple enough to keep the translation chart up while I wire it.

Also, is there any way for me to make my image attachments not look awful and recompressed?

 

[sumitagarwal]

Re: Converting a humbucker to RWRP?

Does anyone who understands this stuff better than me think this looks right or wrong?

 

[PFDarkside]

Re: Converting a humbucker to RWRP?

Can you explain the reason why you’d rotate a pickup rather than flip the magnet? Is it because in this case you’d have a pickup made of two identical coils with the same pole pieces? Since you are doing it to achieve hum cancelling all you really need to do is split to the other coil (which is what the color swaps do) right? Rotating is just to change what segment of the string is being sensed so it’s really up to preference, right?

(I understand the original idea is to flip the magnet, swapping the magnetic polarity, then swap wires to flip the phase from the Coils)

 

[sumitagarwal]

Re: Converting a humbucker to RWRP?

Can you explain the reason why you’d rotate a pickup rather than flip the magnet? Is it because in this case you’d have a pickup made of two identical coils with the same pole pieces? Since you are doing it to achieve hum cancelling all you really need to do is split to the other coil (which is what the color swaps do) right? Rotating is just to change what segment of the string is being sensed so it’s really up to preference, right?

(I understand the original idea is to flip the magnet, swapping the magnetic polarity, then swap wires to flip the phase from the Coils)

Sorry for any confusion on that. This wiring has two different middle hum-cancelling single-coil positions. My goal was to get a bigger difference between the two positions by having one position be outer coils ("Tele-style mid position") and having the other position be inner coils ("Strat-style north position").

My understanding is that unless I rotate a pickup or flip a magnet, I'd end up with a position with both pickups' neck coils, and a position with both pickups' bridge coils, with much less tone difference between both modes.

 

[PFDarkside]

Re: Converting a humbucker to RWRP?

That makes sense.