Wiring diagram verification

[whitekeys]

Hi, I'm changing just the neck pickup on my hollowbody Cort Yorktown for SD P-rails and I'm not sure with a diagram i made, it's for 2 HBs 3 way switch, 2 volume pots and 2 tone push pull pots. I want to have a possibility to change ''coil selection'' and parallel/series on neck pickup with these push pulls.

Guys, could you please confirm me the diagram? I'm not 100% sure with it, original diagram is from SD web. I changed this a bit for my purposes.

Here's the link : img851.imageshack.us/img851/5693/prailsschema.jpg

BIG thanks for help !

[ashcatlt]

Welcome aboard!

The diagram you've linked will do as advertised (assuming you've got wire colors correct), but leaves a coil hanging from hot in the "up-down" position. Luckily you've got plenty of unused lugs to fix that.

Check out ChrisK's Binary Tree, specifically the upper right "DPDT Cell". His schematics are sometimes a little fought to follow, but this one is pretty straight forward.

[whitekeys]

Thanks for reply!
I'm not sure if I understand you well, I am from the Czech republic, so my english is not the best.

I only want to control with push pulls the neck P-rails pickup.

What you mean with ''leaves a coil hanging from hot in the up down position?''
Red wire going out of left side of left push pull is not there. I just changed this diagram cdn.seymourduncan.com/images/support/schematics/2_prails_2v_2t_tspp.jpg and erased this red wire.

This scheme is for 2 p rails, but bridge Cort pickup stays.

Can you please tell me what should i do with my diagram? I'm a litte desperate right now, I wrote on seymour duncan forum before, but with no response..

Thanks a lot

[newey]

whitekeys-

Hello and Welcome to G-Nutz2!

As Ashcatlt said, your diagram will work. The issue of the coil "hanging from hot" doesn't affect the operation of the circuit. It may contribute to some added noise when you have the switches set so that the one on the left is up and the one on the right is down. (This is the setting for the rail coil alone).

There is no guarantee that leaving a coil hanging will actually make it noisier. Noise is an issue subject to many variables. We all try to avoid having a coil hanging from hot when possible; sometimes it's not possible to avoid. Avoiding hanging coils is just one of those good practices to follow.

To see what we mean by the coil "hanging from hot", imagine the switches set to the " left up-right down" position. Trace the wiring. You will see that, for the P90 coil (the one with the white and black wires), the black wire is connected by the left side switch to the output (via the volume pot, to the pickup selector switch, and from there to the jack).

The wire that would normally be grounded, the white wire, is disconnected with the right side switch in the "down" position, leaving the P90 coil connected to the positive side, but disconnected at the negative side. This is what we mean by "hanging from the hot"- the coil is switched "off" by disconnecting the grounded end only and leaving the "hot" side connected.

You have a choice to make. You can either wire your guitar just as you show it on your diagram, and hope that the "up-down" setting is not unduly noisy compared to the other settings. If it does generate noise in that setting, you might need to go back in there and fix the "hanging from hot issue" in the future.

Or, you can solve the potential issue now, by using the other half of one of the switches (since you're only using the one P-rails pickup, you have one pole free on each switch.) The link to ChrisK's "binary tree" diagram shows how to do this.

If you wish to avoid the "hanging" issue and you can't follow ChrisK's diagram, let us know and we'll walk you through it.

[newey]

And a note to all members:

ChrisK noted that the "binary tree" arrangement was not original to him, and in fact wolf had used the scheme before.

But, I note that ChrisK started his post in May 2007, and the SD diagram is copyrighted in 2008.

Hmmmm.

I, too, am a big fan of the "binary tree" switching. My P-bass project uses it, and my 4Caster has a "doubled" version of it. It seems a bit confusing to use at first, but one quickly gets used to it.

[whitekeys]

Oh, now I see, guys really thanks. I can finally get to it. I think I will figure out binary tree wiring with help of my brother, really thanks.

I will maybe look like a jerk now, but do anyone know how to get out this hudebniforum.cz/download/file.php?id=3842 rubber circle around pickup switch so I could do the rest? I don't want to harm my guitar, so i'd like to ask first, before i will try brute force. Thank you.

[reTrEaD]

May 12, 2012 9:35:56 GMT -5 whitekeys said:

I don't want to harm my guitar, so i'd like to ask first, before i will try brute force. Thank you.

Brute force won't help here. Look carefully at the metal ring. It has two slots in the top of it. Basically it's a "nut". You need a special tool to turn it counter-clockwise to unthread it.

[whitekeys]

I have a problem, i want to pull all electronics through the f hole, but black ground wire connected with bridge is too short to reach the f hole. I think I can cut it inside the guitar and pull this wire out of one of potenciometer holes closer to bridge, than somehow extend this wire and finally pull it through the f hole. Can you please tell me, how should I do it? I mean extending the ground, so it won't be crappy or how should I deal with this?

Thanks with the ''rubber circle thing'' i tried to unthread it with 2 tools yesterday but with no succes, today i used thin pliers and did it.

[reTrEaD]

Cutting the wire sounds like a bad idea to me. If it's too short to allow being desoldered outside of the guitar, how will you solder it when you need to reconnect it?

Take your bridge pickup off and see if you can pull the electronics out that way, rather than through the f-hole. Maybe you'll have more wire length to work with.

[newey]

I agree with pɐƎᴚ⊥ǝᴚ. Don't cut that wire just yet, if you do you'll never be able to resolder it. Trying the bridge pickup opening is a good idea. If you can't get the harness out that way, you may still be able to get enough access to the bridge ground wire in order to solder an extension wire onto it before disconnecting everything.

While it doesn't address your particular question, I thought this two-part video had some good tips on the general issues involved in rewiring a semi-hollow guitar. In particular, note how he uses a large Tie-wrap™ to stiffen his new wiring harness.

[whitekeys]

This is the final diagram with binary tree applied. I hope you'll get it, it's ugly i know.. Is it ok now? imageshack.us/f/215/prailsdiag.jpg/

About the ground wire.. I'll try to unsolder the ground from one potenciometer and then pull it out. It's a little bit twisted inside the guitar ''around'' one potenciometer

I can get this potenciometer near the f hole, but not outside of it, because the wire is tangled...

Guys, really really thanks for your time !

By the way, newey, i see you are from Akron, one of my most favourite bands, The Black Keys are from Akron !

[newey]

The Black Keys are from Akron !

Yes, they are, although now that "they made it big" they've moved to Nashville; Auerbach built a studio there.

I should be able to say "I saw them back when . . .", but I can't, I've never seen them live. Their album "El Camino" is usually crankin' on my car stereo, however.

Auerbach just finished producing the new Dr. John album, and what I've heard of it so far is really good. (I say that not ever really having been a big Dr. John fan.)

[whitekeys]

Me neither, but i wanted to go to Germany to see them, but it's too expensive for me because it's a big festival.. I hope they'll come to Czech republic next Europe tour..

Guys what about this, is it ok ? img215.imageshack.us/img215/5954/prailsdiag.jpg

My brother made this, he said you should get it, though i think it's a mess.

I guess this is the last thing that stops me, if it's ok, I can finish it..

[newey]

White-

Your diagram looks fine. Make sure you test everything before you reinstall the pots.

[whitekeys]

My brother asks, do all wires have to be shielded?
On stock wiring, they were(except ground), but on some photos he's seen some wires were not shielded..

[reTrEaD]

No, wires never have to be shielded. As long as all the connections are made a circuit will function. The hum-suppression shielding provides will vary in effectiveness, depending on the length of the wire and the presence or absence of cavity shielding.

[newey]

It's a good practice to use shielded cable for all wire runs of any length in a semi-hollow bodied guitar, provided the wire in question carries signal.

Certainly from the pickups to the controls should be shielded cable. The bridge ground doesn't need to be shielded, as it's not carrying signal. Short lengths of wire between the pots probably don't need to be shielded.

I would use a shielded cable for the run from the switch to the output jack.

EDIT: Ninja'd by pɐƎᴚ⊥ǝᴚ! He's right, no point to putting shielded wires inside a shielded cavity, but since this is a semi-hollow body I'm assuming no such shielding (or a cavity, for that matter) is present.

[reTrEaD]

May 14, 2012 15:41:22 GMT -5 newey said:

EDIT: Ninja'd by pɐƎᴚ⊥ǝᴚ! He's right, no point to putting shielded wires inside a shielded cavity, but since this is a semi-hollow body I'm assuming no such shielding (or a cavity, for that matter) is present.

I think you are reading more into that, than I meant to say. I still use shielded cable for longer runs, even in a shielded cavity. But since most of the work has already been done by the cavity shielding, the yield is rather small. Belt AND suspenders sort of thing.

[whitekeys]

I use this:
























(EDITed by sumgai to make the image show up.)