Wiring Insanity Strikes Again?........

[soulman969]

I'm beginning to wonder if electricity works differently around my place than it does everywhere else in the world. Here's another puzzler, but first some history.

Some of you may remember the challenges I had a few months back upgrading my CVC with Keystones and a 4-way. All of my many attempts to get it working using the conventional wiring scheme with the B/N Series in position #4 failed even though I wired it the same way the 4-way in my 95 MIM was wired which worked perfectly.

I ended up taking it to a luthier friend of mine nearby who also failed to get it working with that scheme even using a brand new switch thereby eliminating the possibility that the first was either damaged or defective. He was eventually able to solve this riddle with a totally different wiring scheme that placed the Series in position #1 with the typical 3-way sequence in positions #2-#4. I have no complaints because I actually like it a little better this way.

The puzzling thing was that it shouldn't really have worked this way at all based on how it was wired and neither he nor a couple of members here who offered valuable advice throughout this ordeal could explain it either. I even posted a diagram of that wiring scheme to see if anyone else had used it successfully and didn't get a single response in the affirmative.

Well my current project has me converting that same 95 MIM into a Nashville configuration using a RW/RP Middle Pickup from a 96 Strat. Since the 4-way was already wired and working perfectly I decided not to mess with it and simply install a P/P Tone Pot to actuate the Middle Pickup instead. This way I keep all four other combinations including the B/N Parallel that's lost on a traditional stock Nashville and just add the Middle Pickup whenever I want it in the mix. Simple enough even for me....I thought.

The Middle pickup is wired with the hot lead to the E terminal on the P/P Pot, ground to the Volume Pot, and a jumper from the D terminal on the P/P Pot to the outer Volume Pot lug. Pulling up on the switch turns the Middle on and leaving it down keeps it off. That checks with the wiring diagram and operation of the switch I have to go by. This works, but in a way I didn't expect at all and I can't figure out why. Maybe the wiring techs and builders can share a though or two. I'd love some advice since I'm stymied.

With the switch off there is still a very weak out of phase type output from the Middle pickup when it's in or near the pickup cavity or attached to the pickguard and set into the cavity. If I remove it from that area and any proximity to the other pickups and just lay it aside on the body it's dead silent as it should be. Put it back and tap on it and there is weak output. It's on a different switch isolated from the wiring of the other pickups so there's no possibility of contact or a short between the hot leads. So what would cause this?

With the switch on the Middle pickup combines with any of the four positions of the 4-way as it should but the B/N Series in position #4 remains B/N Parallel just as it does in position #2. I didn't expect the Middle to be in Series with the B/N Series combo because it's not wired into the Series circuit but I did expect the B/N to be in Series combined with the Middle in it's normal state. As it stands with the Middle on position #4 simply duplicates position #2, B/N/M Parallel.

If I switch the Middle off I get B/N Series in position #4 put with that weak out of phase output from the Middle pickup in there as well. So no matter what pickup selection I use with the Middle off it's still contributing that weak output to the other single pickup selections or combinations. Typically when I throw a switch to off what ever it operates turns off not half way off. Apparently someone forgot to let this switch in on those regulations.

Any best guesses out there. I'm a little out of them at the moment.

[JCollins]

You might try adding a jumper between the F lug, on the P/P, to ground. That way, when the middle pickup is not engaged, it will be shorted, so you shouldn't get any sound from that pickup, at all.

See if this works. It could be a bad push/pull. You could also try lugs A,B, and C, on the P/P, instead of D, E, and F. The two poles in that push/pull are supposed to be independent.

I can think of no reason why the B/M series should suddenly become B/M parallel. Is that new pickup in phase with the other two? An RW/RP pickup is only RW/RP with respect to some other pickup.

[soulman969]

Originally Posted by JCollins

You might try adding a jumper between the F lug, on the P/P, to ground. That way, when the middle pickup is not engaged, it will be shorted, so you shouldn't get any sound from that pickup, at all.

See if this works. It could be a bad push/pull. You could also try lugs A,B, and C, on the P/P, instead of D, E, and F. The two poles in that push/pull are supposed to be independent.

I can think of no reason why the B/M series should suddenly become B/M parallel. Is that new pickup in phase with the other two? An RW/RP pickup is only RW/RP with respect to some other pickup.

Good thought on that extra jumper from the F terminal. I'll give that a shot in a bit and if that doesn't do it I'll shift the connections to the opposite terminals next. That might determine whether or not the P/P Pot is at fault.

The Middle pickup is RW/RP to both the Neck and the Bridge pickups which are stock Alnico V's. I confirmed that when it arrived since I was sent one previous to that which wasn't RW/RP. It is what it's supposed to be.

In position #1-B/M or #3-N/M with the Middle on the pickups are in Parallel just as they are when all three are on in combination in position #2. It's when the Middle is on and I shift to position #4 which is B/N in Series that they become B/N Parallel. My expectation was that those two would remain in Series with the Middle just added to that separately since it's independent of the 4-way switch and not wired in Series with the Bridge and Neck.

[Wally]

Apologies......

[soulman969]

Originally Posted by Wally

NO matter what the B/N wiring is in position #4, that middle pickup is still RWRP to them and throws that combination out of phase, doesn't it? MErely switching that middle pickup in for the B/N Series position cannot possibly change the B/N relationship. The B/N are still in series in that position. IT is the relationship of the middle pickp to that series combi that is giving you that thinner out of phase result.

I don't know Wally. That's what I'm trying to grasp. In Pos #4 B/N are in Series on my 4-way. With the Middle off they do combine in Series except that in this case the p/p is not shutting the Middle off completely. There is still very weak output in all positions even when it should be shut down completely.

In Pos #4 with B/N in Series when I actuate the Middle pickup the B/N in Series reverts to B/N Parallel. Despite the nature of the Middle pickup the B/N are still wired in Series to each other so why does the introduction of the Middle affect that? The Middle wouldn't also be in Series because it's not wired in Series with the other two so I would expect it only to add to the others not override the wiring. Isn't that what controls the relationship of the Bridge and Neck or is that what I'm not getting?

I took JCollins advice and wired the jumper from F to ground but the results were the same. Still weak output from the Middle with the switch off. I also wired it all to the opposite terminals (A,B,C) first without a jumper from C to ground then with but no change either way. There is still a very weak but audible output from the Middle with the switch off.

So does this lead us to the conclusion that the switch is bad? Unwired the meter readings from the terminals are; Switch On D-E = .01 and E-F = no reading. Switch Off D-E = no reading E-F = .01. Is this where the problem is coming from? Should there never be a reading between E-F no matter what position the switch is in?

Pardon my elementary level understanding of these micro electronic issues. I haven't had much experience with this stuff and though some of it is sinking in it's still sinking in slowly. That's why I appreciate the input and advice from the experts here. Little by little I'm getting better at it but since I learn by doing rather than from the telling unfortunately my lessons generally come from doing something wrong before I get it right.

Needless to say this attempt is going much better than the last (about a 100% improvement on my soldering skills) but I'm stumped as to why there is any output at all coming from the Middle with the switch in the off position. As I said in the OP, if I remove it from it's installed location in or around the pickup cavity between the two pickups it's silent. Put is back and there is weak output with the switch off.

Needless to say that has me stumped. As does the reason why although B/N are wired in Series in Pos #4 the introduction of the Middle pickup changes that relationship from Series to Parallel. B/M and B/N would combine in Parallel as would all three in Parallel but how does the B/N Series get overridden when the Middle is on?

If that's just the way it works then why doesn't the Middle interfere with B/N Series in the off position when there is still some output from it in the circuit?

So these are the two issues I'm trying to straighten out. How to get that Middle shut down completely in the off mode and how, if at all possible, to keep it from kicking B/N Series into B/N Parallel when it's on.

[JCollins]

Originally Posted by Wally

NO matter what the B/N wiring is in position #4, that middle pickup is still RWRP to them and throws that combination out of phase, doesn't it?

No, it does not throw that combination out of phase. Whether two (or three) coils are in phase is dependent upon how they are connected in the circuit, not whether one is RW/RP with respect to the other coil(s). In physics, there is a memory device known as the "right-hand rule". Make a fist of your right hand, with the thumb pointing out. Your thumb represents magnetic north, and your fingers represent the direction of current flow. This is also an excellent representation of a single coil. Notice that, no matter how you orient your hand, the fingers still point the same direction, relative to the thumb (magnetic north). Coils of different magnetic polarity can be wired into the same circuit, all in phase, as long as the normal direction of current flow, through each coil, is respected. A normal humbucker pickup, for example, can be thought of as two right hands, right next to each other, with the thumb of one pointing up, and the thumb of the other pointing down. This is exactly the representation of two coils RW/RP with respoct to each other. A third coil, in phase, is nothing but a third right hand, however you'd like to orient it.

It would help if you could draw a picture of the wiring. (Photos are never clear enough.)

Also, is this guitar shielded? It may be possible that the middle pickup is making accidental contact with the shielding, when the pickup is mounted.

[Wally]

Pardon...I hit the wrong button....

[soulman969]

Originally Posted by JCollins

No, it does not throw that combination out of phase. Whether two (or three) coils are in phase is dependent upon how they are connected in the circuit, not whether one is RW/RP with respect to the other coil(s). In physics, there is a memory device known as the "right-hand rule". Make a fist of your right hand, with the thumb pointing out. Your thumb represents magnetic north, and your fingers represent the direction of current flow. This is also an excellent representation of a single coil. Notice that, no matter how you orient your hand, the fingers still point the same direction, relative to the thumb (magnetic north). Coils of different magnetic polarity can be wired into the same circuit, all in phase, as long as the normal direction of current flow, through each coil, is respected. A normal humbucker pickup, for example, can be thought of as two right hands, right next to each other, with the thumb of one pointing up, and the thumb of the other pointing down. This is exactly the representation of two coils RW/RP with respoct to each other. A third coil, in phase, is nothing but a third right hand, however you'd like to orient it.

It would help if you could draw a picture of the wiring. (Photos are never clear enough.)

Also, is this guitar shielded? It may be possible that the middle pickup is making accidental contact with the shielding, when the pickup is mounted.

That was my understanding too. The Middle won't combine with the other two in Series because it's not wired in Series with them but it should add it's character alone without changing that of the other two. Pos #4 B/N are wired in Series and should remain in Series whether the Middle is in or out of the circuit. Unfortunately right now that's not how it's operating.

The guitar is not shielded. The stock pickup and control cavities have only the LPB body paint covering them. Since the new rout for the Middle pickup (a single pickup rout, not a bathtub rout) was just bare wood I shielded it initially but pulled the shielding out when I was going through my normal process of elimination. No change.

I've changed all of wiring back to the D and E terminals again, including running a ground from terminal F to the Volume Pot as you suggested, with an interesting discovery. The Middle (off) is silent when the 4-way is in the Neck Only #3 position but not the others. The key question I still have is why will the Middle pickup (in off mode) become totally silent when it's not in or near the pickup cavity yet have a weak output in #1,#2, and #4 when it is?

This is a pretty simple straightforward conversion of stock Standard MIM Tele with a 4-way and treble bleed to a Nashville with a RW/RP Strat Middle dropped in between the other two and wired separately of the 4-way directly to a P/P Pot. Surely the other pickups shouldn't be affecting it or every Nashville would have the same problem.

I will draw a diagram of the new wiring to post but I probably won't get to it until tomorrow. Other priorities call this evening. But in the meantime the 4-way and treble bleed are wired as per the SD and/or Acme standard diagram for a 4-way with B/N Series in Pos. #4. Nothing out of the ordinary and it works exactly as it should independent of the Middle pickup.

Thanks for the help and advice guys.

[sjtalon]

Like soulman said, the 4 way WAS in the guitar, working fine. STANDARD Fender 4 way scheme.
Installed the middle pup, and a p/p pot, the p/p switch doing the "middle on"

This is how he has the p/p:

[Wally]

Okay, I need education on the correct terminology, I suppose. SJtalon, can you expalin to us why the OP thinks that the #4 position is going to parallel from series when he brings that middle pickup online??? OBviously, the wirirng of those outside pickups in position #4 has not changed...they are still in series with regard to each other. So, if the sonics go 'thin'....what the OP is callling parallell.....when the middle is joined with the #4 series arrangemnt, what is the correct terminology for whatever that middle pickup's introduction to that series arrangement? IT has to be related to the RWRP of the middle pickup and its realtionship to that series arrangement, doesn't it?

[JCollins]

The pickup might be out of phase with the other two, but that is independent of whether or not the pickup is RW/RP with respect to those other pickups.

The symptoms would normally make me think that something is out of phase, which is why I'd like to see a drawing of the wiring. Soulman969 mentioned that the wiring of the two pickups, with the 4-way switch, was done with a different wiring. That may be the wild card, here, because the description of the middle pickup wiring is simple, and would appear to be correct.

[tfsails]

Not having seen a wiring diagram with a schematic of the new switch, I'm sort of postulating blindly here, but here's what I think:

You say in position 4 with the middle pickup off the B and N are in series. You think the B/N reverts to parallel when the M is switched on. I think what you have here is a series/parallel circuit where the B/N are still in series but that combination is now in parallel with the M when the M is turned on. Assuming this is the case, you would normally sense some diminution of the B/N output at this time.

I suspect you're trying to get some Strat "quack" with the middle pickup. It just might be to your advantage to not use it when you have the switch in B/N series position and just use it when you have B only or N only selected, just like if you had a 5-way switch on the guitar.

As to the M pickup still having some output when supposedly "off", the pickup is still creating a signal when you move the strings even though it's deselected at the switch (actually it's electrically disconnected from the signal path). Sometimes if several unshielded wires are routed parallel (not to be confused with electrical "parallel") to one another a signal from one can induce a signal in other wires. This may be happening in your guitar. A solution may be to change the wire routing as much as you can to where the wires do not run parallel to one another. Hard to do in a limited space.

Another solution may be to use shielded wires from the middle pickup and ground the shields. That should absolutely eliminate any spurious signals.

Good luck and keep us posted!

[Wally]

Okay, JCollins...I understand that. So, if that #4 position in combination witht he middle pickup is 'thinner' sounding and humbucking, it is parallel and out of phase, right? IF that combination is non-humbucking, then it is parallel and in phase, right?

[Wally]

And....since the OP 'hears' that the arrangement is parallel.....thinner sounding....I am going to say that the arrangement is parallel out of phase(humbucking) with regard to the neck/bridge series out of phase(humbucking) relationship combined with that RWRP middle p-up. ???

[soulman969]

Originally Posted by Wally

Okay, I need education on the correct terminology, I suppose. SJtalon, can you expalin to us why the OP thinks that the #4 position is going to parallel from series when he brings that middle pickup online??? OBviously, the wirirng of those outside pickups in position #4 has not changed...they are still in series with regard to each other. So, if the sonics go 'thin'....what the OP is callling parallell.....when the middle is joined with the #4 series arrangemnt, what is the correct terminology for whatever that middle pickup's introduction to that series arrangement? IT has to be related to the RWRP of the middle pickup and its realtionship to that series arrangement, doesn't it?

Sorry, it's taken me a day to get back on. I can explain that Wally. There is a definite sonic difference in the sound the Neck and Bridge pickups when you tap on them. Obviously the Series Combo will sound deeper and boomier than the sound when they're in Parallel.

Maybe my terminology is incorrect and I should be describing it as an "out of phase" sound but despite the terminology the relationship between the Neck and Bridge hasn't changed. They are still wired in Series in Pos. #4 and it's the sound of those two that changes. I also have Pos. #2 which is B/N Parallel to compare it to. It's the same.

Originally Posted by JCollins

The pickup might be out of phase with the other two, but that is independent of whether or not the pickup is RW/RP with respect to those other pickups.

The symptoms would normally make me think that something is out of phase, which is why I'd like to see a drawing of the wiring. Soulman969 mentioned that the wiring of the two pickups, with the 4-way switch, was done with a different wiring. That may be the wild card, here, because the description of the middle pickup wiring is simple, and would appear to be correct.

My adding that story about my experience with the CVC may have confused you JC. That guitar was wired differently. This MIM I'm converting is wired with a standard 4-way wiring scheme using the SD or Acme wiring diagrams that place the Series Combo on Pos. #4.

So if you look at either of those two 4-way wiring diagrams (the Seymour Duncan or the Acme) that is precisely the way this MIM is wired as far as the Bridge and Neck pick up are concerned.

Now add to that the exact wiring of the P/P Pot that sjtalon posted along with a jump wire from the outer to lug of the P/P Pot to the outer lug of the Volume Pot and you have it. Sorry I've been tied up and haven't had the chance to post a complete diagram but what I've described above is it.

With the P/P Switch on the Middle Pickup is in phase and operates normally in combination with the others; Pos. #1 = N/M, Pos. #3, N/M/B = Parallel, and Pos. #3 = N/M. Pos. #4 is the only one affected incorrectly with the switch on.

With the P/P Switch off the Middle is still providing weak output in every combination but Neck Only. There it is silent and it is silent when removed from the proximity of the other pickups.

Hope this clarifies a bit.

[sjtalon]

Thanks for the thinkin' caps guys ! I really can't explain the tone he gets there.

All my part in it was suggesting how he could EASILY (famous last words) add the middle pup.

To make things SO EASY, I say, leave your nice 4 way, and just put in a p/p tone pot to engage the middle pup.

So, simple deal right, he has a MIM Tele with the standard Alnico V pups from that era. 4 way switch, regular 'ol Fender wiring scheme. That has been how the guitar was set up some time ago and that all worked HONKY DORY.

So getting interest in a Nashville set up after hearing me brag about mine, he decides to make his a Nashville.

Those Tele pups are both North top. So he gets a USA STRAT middle, VERIFIED south top. This will give noise cancel with either the N & B. He was lucky and said the phase was right with the others with the white to the switch, red to ground, which is correct for that era AM Strat pup as well. Not that that means anything, it is just a coil connection, and could go either way.

[soulman969]

Originally Posted by sjtalon

Like soulman said, the 4 way WAS in the guitar, working fine. STANDARD Fender 4 way scheme.
Installed the middle pup, and a p/p pot, the p/p switch doing the "middle on"

This is how he has the p/p:

Thanks for posting this pardner.

Yes, this is the exact wiring I'm using for the P/P Pot with one slight addition. There is a jumper going from the outer lug of this switch to the outer lug of the volume pot just as there is between a standard tone pot and the volume pot. Is that wire unnecessary in this scheme?

[sjtalon]

here she is :

[sjtalon]

Fender 4 way:

http://www.blueguitar.org/new/schem/_gtr/tele4way.jpg

[sjtalon]

Originally Posted by soulman969

There is a jumper going from the outer lug of this switch to the outer lug of the volume pot just as there is between a standard tone pot and the volume pot.[/COLOR][/U][/I] Is that wire unnecessary in this scheme?

I don't get what you are saying there ?? Saying there is an addition ??

You only have TWO wires on the p/p right ?? The SWITCH part.

Those pictured, BLACK AND BLUE ( or what ever you used)

You have to have a wire to the vol pot to send the signal (middle pup) there when you pull up on the knob. Is that what you are calling the "jumper"