superstrat wiring

[simes]

Hello.

I had actually meant to consult the collective wisdom of this forum some time ago, but have only had my account approved today. This was apparently due to a technical hitch - something I am well familiar with on my own non-guitar-related website - so all is forgiven.

My original intention was to ask for suggestions on rewiring an old strat copy, but I now have the matter more or less resolved, so I will limit myself to asking for comments on what I'm already doing.

The guitar in question is a Fenix Strat, bought in 1992, which (for numerous and tedious reasons), spent 10 years lying under a bed until a couple of months ago. Its innards were therefore in a lamentable state when I got it back, and I decided to do some renovation and rewiring.

This is actually a really good strat, with loud, relatively noise-free pickups, of the "hermetically sealed" type. However, I wished to resurrect it as a stage guitar, and so needed more pickup combinations than it previously offered. I was given a Gotoh humbucker with PAF-style metal cover, so I decided to do the following (I aim to start tomorrow):

First, the "middle" tone control had to go, since I never play with the middle pickup alone, and it would be far happier serving the bridge pickup. This would allow me to get my favourite Ed King lead tones by setting a trebly amp and rolling off the top end at the guitar. This amp setting would also make (to my ears, at least) the neck/middle and neck sounds more palatable.
Second, a "neck on" switch must be installed to allow those "Keith" rhythm sounds or similar.
I got these two diagrams from the revered Guitarnuts site, so this shouldn't be too much of a problem. I will say, though, that I'll be using mini-switches instead of push-pull pots. I just like them better, and it's not as if I'm ruining a vintage Fender scratchplate or anything ...

Now, then. I want the humbucker in at the bridge, and have cut the scratchplate accordingly. I aim to route the guitar body a little tomorrow. I'm going to run this HB through the second mini-switch in order to set the two coils as series or parallel.

All three new pots are 500K.

The problems I anticipate are:
- ruining the HB when trying to wire it for series/parallel
- the HB giving a slightly uneven sound due to the string spread at the bridge
- the 500K pots being more suitable for the HB than for the two remaining SC's
- repenting once it's too late, after having scarred my faithful Fenix for life

Any comments are more than welcome. On second thoughts, only relatively benign comments are welcome, this being both my first post and my first serious guitar mod.

Thanks.

Simes

[UnklMickey]

i don't see a big problem with the 500k pot and SCs. your tone controls will be a bit more abrupt near full cut.

i agree fully on the tone control for the bridge PU. never could understand why F didn't do it that way.

are you really sure you want a HB at the bridge? How about a slightly underwound SC rwrp right next to the existing SC? you can keep the diagonal orientation and everything. just wire it with the existing PU as the second coil of your new STAGGERED COIL DIAGONAL HUMBUCKER. you can even tell your friends and colleagues it came from an original design (i think it's original?) by Unklmickey!

i'm considering this as one of many possible configurations for my Junior. if you do yours this way, you'll have the first (to my knowledge) 'cause junior is scheduled for a winter project.

Happy routing!

U.M

[simes]

Hello.

Well, I've routed the space for the humbucker (I've got it so I prefer to use it rather than installing a 4th SC), wired up the bridge tone control and the neck on switch, extracted four wires from the HB and wired it in via a home-made shielded 4-conductor cable to a mini-switch.

The neck on switch works. I assume the bridge tone works too, but I can't be sure because the HB doesn't.

The problem, presumably is either (a) the HB is a dud (b) the HB is incorrectly wired (c) the shielded cable is faulty (d) the mini-switch is wrongly wired. I suspect (b) or (d).

Please bear in mind that my ignorance of electronics is almost total, and that I may have misunderstood or misnamed any number of things.

OK, the HB originally had two black wires and two red wires inside it, one black and one red for each coil. The two blacks were connected together. The red from the coil with the screw polepieces (let’s call it Coil A) was connected to the inner wire of a single-conductor shielded output wire. The red wire from the non-screw polepieces coil (call it Coil B) was soldered to the pickup base, as was the bare shielding wire of the output cable.
As far as I know, this was how it was wired by the manufacturer. It's a Gotoh, by the way.
This led me to assume that the red wire from Coil A was “hot” and the black one “ground”, while Coil B would be black “hot” and red “ground”. This seemed a little strange to me, since it would be more logical for both “hots” to have the same colour, and both “grounds” to have a different one.

Anyway, I made a 4-conductor shielded cable and connected it to a mini-switch as follows (imagine a six-pole on/on mini-switch standing on its end, with three horizontal rows of two poles):
Coil A red wire to top left pole, wire from this pole to pickup selector switch
Coil A black wire to middle right pole
Coil B red wire to middle left pole
Coil B black wire to bare shield wire to back of volume pot
Top right pole also connected to back of volume pot
Bottom two poles wired together

I am a little lost, and would appreciate some help.

Thanks,

Simes

[simes]

It might be easier to actually see the way I wired the mini-switch, rather than visualising my description. I followed the series/parallel diagram at:

www.guitarelectronics.com/category/wiringresources.1wiringdiagrams.humbuckerwiringmods/

[UnklMickey]

simes said:

...Any comments are more than welcome. On second thoughts, only relatively benign comments are welcome, this being both my first post and my first serious guitar mod. ...

okay, since this is your first time, i'll be gentle. .:rofl:.

seriously though, this is GN2, these folks are glad to help, but we also take ANY opportunity for humor. it's all in fun, NEVER mean-spirited.

as far as the color codes go, they apparently have chosen to indicate the winding direction with the colors. since each coil of a HB is in an opposite magnetic environment (one is north one is south), the electric signal created in the coils by the strings interaction is opposite. that's why the two blacks are connected together. external e.m. fields (hum) cutting through those same coils are (although having a very slight shift in phase) in the same polarity. thats how a HB can cancel hum.

for your wiring problem, get an ohmmeter. i assume when the bridge switch is off, the HB is disconnected and not shorted. switch the bridge off and measure from the top left lug of the s/p switch to the top right lug. in the series position you should read the total resistance of both coils. the coils usually have a slightly different resistance. your A coil might have a resistance of say 5500 ohms and the B coil maybe 4500 ohms. but for this analysis we'll assume they're identical. lets say they're 5k (5000) ohms. so the series measurement should be 10k. the measurement with the s/p switch in the parallel position should be 2.5k. so if you got measurements that were on this order (say 22k series and 5k parallel OR 8k series and 1.9k parallel) then the coils and s/p switch are OK. so at the output of the switch you should be able to produce a signal from the strings (assuming you didn't leave the magnet out .:lol:. ;D).

don't get too hung-up on exact numbers here. if you're reading resistances like 20 ohms (a short) or 100,000 ohms (an open) that obviously indicates a problem.

btw: since the movable (center) contact of a switch is referred to as the pole, and the outer contact as the throw, i prefer to reserve the term "pole" just for the movable contact, and use the general term "lug" or "pin" to refer to external connection points (although in some cases they are tall and cylindrical like a pole) to minimize ambiguity.

good luck

U.M.

[simes]

Thanks for the reply, unklmickey.

OK, a few observations.

So far I’ve tried wiring the HB/switch in two different ways, neither of which worked. I suspect this was due to not identifying the HB wires correctly. I was rather surprised not to get any sound at all, however.

I’m assuming that the “screw coil” is always south and the “flat coil” is always north. From your comments on the colours indicating wiring direction, I’m also assuming that the red HB wires are both “start” and the two blacks are both “finish”. If I connect this up to the switch as shown in the series/parallel diagram as indicated in my last post, this will give a different configuration to what I had before. I will try this tonight.

One thing which may or may not be relevant, but which surprised me, was that if you place the HB so the screw coil is nearer the bridge, all the wires come out of the side opposite the controls, meaning that I have to run the shielded 4-conductor underneath it in order to reach the controls. Could this be because it is really a “neck” PU? Or is the configuration of a “neck” HB the same as that of a “bridge” HB in terms of polarity and wiring?
The reason I mention it is that it was given to me by a friend (who is not at hand to help me with any of this) who had built a Tele. This guitar had a HB at the neck, and the PU he gave me was left over from a second Tele project which never came to fruition.

I am a bit worried about damaging the pickup and other components with so much clumsy soldering.

By the way, the bridge does not have an on/off switch. The five-way strat selector controls the PU’s as usual, except for an added “neck on” switch. At the moment I only get sounds out of N, N+M and M. The other two positions only give a sound when the “neck on” is on.

Your resistance measuring instructions sound a little intimidating (I really have only the vaguest idea about these things), but from what I understand, this is simply a way to check that neither the PU nor the switch is faulty in itself.

The magnet? Yes, I left that in place. I can tell by all the screws and springs that suddenly attach themselves to the PU at convenient moments when I’m holding components in place with all four limbs, gripping the scratchplate between my teeth and manoeuvring the soldering iron with subtle eyelid movements. Maybe I didn’t put enough coal in before firing up; I didn’t notice much steam coming out of the jack ...

As always, any comments would be much appreciated.

Simes

[sjon]

Good morning.

I have finally got round to wiring this project up correctly, and now everything works.

The 500K pots are fine. The sound is generally clearer, possibly due to the fact that the guitar now has quality pots.

The HB series/parallel switch works as intended. The parallel position has a touch of "quack", sounding more like an "in-between" position than I expected, with the coild being so close together. It is also as loud as the series position (or just a little less), which is surprising. It's a good sound, though.

The only problem I see is that the HB has "G" spacing of the polepieces rather than "F" spacing, leaving the E-strings a little outside the polepieces. Actually, the low E is almost above the polepiece and sounds fine, but the high E is outside of the polepiece and sounds quieter. I suppose I could get a new scratchplate and cut it so that the pickup is a couple of mm further across, but I'd rather not.

I realise that I should have considered this before doing the modification, but didn't through ignorance. Is there any way to expand the magnetic field of a polepiece so that it will catch more of that top E?

Another question. Is there any way of wiring a 3-way mini-switch so that it goes "nothing - neck-on - neck-on-phase reverse"?

[sjon]

"simes" and "sjon" are one and the same. These are two different usernames I set up when unsuccessfully trying to sign up a while ago. I will delete one of them.

[simes]

Hmmm ....

I'll continue talking to myself, then.

Setting aside the other questions I had (top E outside the magnetic field; 3-way mini-switch), which are now of little concern to me, I have detected a rather strange phenomenon.

This is the first time it's happened, which leads me to suspect it may be a loose connection, but I'm not sure.

My modified Strat, with its series/parallel switchable HB at the bridge, its "neck on" switch and its bridge tone pot, has started giving a very weak, muffled sound under certain circumstances. With the 5-way in the bridge position, I can switch between series/parallel wiring of the HB coils, and I can add in the neck SC. Sometimes I add the neck to the parallel HB. Sometimes I add it to the series HB, sometimes I switch the HB from series to parallel with the neck SC already engaged.
In the course of this, the HB suddenly goes all muffled. I then switch about a bit more and it comes back. I didn't have time to make a comprehensive study of this, but there doesn't seem to be any pattern beyond the one I've described.

Any ideas?

[UnklMickey]

okay, last things first.

sounds like maybe you overheated your switch(s) during soldering.

if you did, and oxidized the contacts, there is some hope of repair. the contact cleaners that are available today are not nearly as effective as the ones available before the freon ban. if you had an open switch, you could clean the contacts with a metal polish, then clean off the polish. but i think you have the plastic switch. you may be able to carefully (don't drip any on the finish) drip some ammonium hydroxide solution (household ammonia) into the switch and operate the switch repeatedly. then rinse with water, and finally with isopropanol.

this will remove any oxide you have on the surface. it won't repair any damage you may have caused by distorting the plastic during soldering.

you can check your progress as you go.

make resistance measurement of the closed contacts between the appropriate terminals. if you initially see resistances of several hundred (or a few thousand) ohms, then after the cleaning, just a few ohms, success.

i doubt you'll be able to clean the mini-toggles, but you should check them and replace if the resistance is high.

if you successfully clean the switch, there is no guarantee on how long before it become problematic again. replacement may be necessary.

another possibility is that some of your wiring is intermittently shorting. moving the switch around may be vibrating it so it goes between almost touching, and just touching.

_________________________________


for that high - e problem, lowering the pup will reduce the disparity of the strings. however this comes at a cost of lower output.

_____________________________


on that mini-toggle, the only way that i'm aware of is: neck on - nothing - phase reverse



oh yeah, BTW, stop talking to yourself. people will think (know?) you're nuts.


U.M.

[Mini-Strat_Maine]

unklmickey said:

oh yeah, BTW, stop talking to yourself. people will think (know?) you're nuts.

"It's okay, we're GuitarNuts. We're trained for this kind of situation." ;D

[UnklMickey]

Simes,

i just had a thought. i'm interested in seeing what the results would be if 47k (or maybe 100k) resistors were placed in series with the wipers of the volume pots, and the cables that go to the selector switch in a 2 volume configuration like yours.

my theory is that it will minimize the coupling without the pickup loading that would occur if the pots are wired bass-ackwards like many 2 volume Gibsons are.

are you game to try this?

[JohnH]

UM - the blender on my ToneMonster2 implies a similar resistance in series with pups. It makes a very slight loss compred to settings which bypass it. It is noticeable but acceptable to me, but Im planning a high impedance buffer after that which should fix it.

John

[UnklMickey]

so in your opinion, would the resistors be a reasonable way to deal with the problems involved with 2 volume coupling. or do you think backward pots is better since you don't have any loss at full on?

[simes]

unklmickey said:

oh yeah, BTW, stop talking to yourself. people will think (know?) you're nuts.

Who? Me or that other guy "sjon" who I hear in my head?

Thanks for the advice, unklmickey. Admittedly my soldering technique could do with some work. I'll look into it.

[simes]

unklmickey said:

i'm interested in seeing what the results would be if 47k (or maybe 100k) resistors were placed in series with the wipers of the volume pots, and the cables that go to the selector switch in a 2 volume configuration like yours.

It's not a 2 volume configuration. There's one volume, plus a neck tone and a bridge tone.

[simes]

unklmickey said:

on that mini-toggle, the only way that i'm aware of is: neck on - nothing - phase reverse

Since it looks like I'm going to have to replace the mini-switches anyway, I might as well add this option. As I have abundantly demonstrated, I am not yet equipped to work out the wiring myself. Any idea where I can get a simple (pictorial) diagram of an on-off-on mini-switch for this?

[JohnH]

so in your opinion, would the resistors be a reasonable way to deal with the problems involved with 2 volume coupling. or do you think backward pots is better since you don't have any loss at full on?

I think given just passive components, Id go with the backwards pots if I got iritated with the volume coupling. But if it didnt bother me (and theres a lot of LP players who know no different), then Id keep the normal pots because iI think it is a better way to wire a pot. My Strat clone came to me with a backwards wired pot (for no good reason since it only has one volume control) and it was particularly prone to treble bleed.

I think with the 100k resistors there would be too much loss, not that it would be much, but enough to annoy. It would be mainly due to cable capacitance. All that could be fixed with a single JFET built-in preamp. Thats my plan anyway.

[UnklMickey]

simes said:

unklmickey said:

i'm interested in seeing what the results would be if 47k (or maybe 100k) resistors were placed in series with the wipers of the volume pots, and the cables that go to the selector switch in a 2 volume configuration like yours.

It's not a 2 volume configuration. There's one volume, plus a neck tone and a bridge tone.

WELL OF COURSE IT ISN"T A 2 VOLUME CONFIGURATION!

your favorite unckle has responded to another thread, and inadvertantly placed that response in this thread.

OOOOPS!


so the stuff i was saying about a 2-volume configuration, from here:

unklmickey said:

Simes,

i just had a thought. i'm interested in seeing what the results would be if 47k (or maybe 100k) resistors were placed in series with the wipers of the volume pots, and the cables that go to the selector switch in a 2 volume configuration like yours.

my theory is that it will minimize the coupling without the pickup loading that would occur if the pots are wired bass-ackwards like many 2 volume Gibsons are.

are you game to try this?

up to this post, doesn't belong.


Sorry for the confusion.