Several Minor Issues with My New Wiring

[OdgeUK]

Hi Guys,

A few weeks ago now I wired a home-built Strat from scratch. It all works, in that the switching activates the correct pickups. I've gigged with it and it seems OK. BUT....there are a number of issues with the sounds it is producing in certain positions, and the tone pot operation.

The pickups are a SD JB JR in the bridge and Texas Specials in the neck and mid. The mid Texas Special is reverse-wound for hum cancelling in positions #2 and #4.

To clarify what I mean by the positions, here it is.
#1 Texas Special Neck Pickup
#2 Both Mid and Neck Texas Specials
#3 Mid Texas Special
#4 Both Mid Texas Special and JB Jr
#5 JB Jr

Now, in addition to this, the JB JR has a spin-a-split (using one tone control) and a master tone (which utilises the remaining tone control). It is also wired for a master volume and the guitar is shielded and star-wired.

The wiring I have done (and double checked) is in the diagram below.

Now hear are my issues:

1) Position #1, #3 and #5 sound good with the character of those particular pickups being very obvious. This suggests that the wiring, for these positions at least, is correct. BUT, position #4 is not that familiar quack nor anything close. It is thin and weak with no sustain or prescence. It sounds like a telecaster in that it has that snappy twang but without any of the warmth. Position #2 is even worse, this position should sound great as it is both the Texas Specials working together (as per a Stevie Ray Vaughan Strat). Instead, position #2 has a very harsh, thin and mettalic sound. it is noticable lower in output to all the other positions and it basically unusable. It sounds like AM radio. Or the funky riff right at the very beginning of the Chilli Peppers "Power of Equality" (you know, when they've rolled off the bass and pushed it right out in the mix).

2) The Master tone pot does nothing until it is right to 0, where it abruptly cuts off ALL the treble and the guitar sounds like you are playing it through a wooly blanket!

3) I A/B'd my Strat with my lead guitarists Richie Sambora signature. Despite me having overwound, high-output Texas Specials his single coil sounds were warmer and fuller than mine, making my guitar seem very underpowered. His bridge humbucker also destroyed my JB Jr for warmth and bass. Surely the pickup selection I have chosen should easily be a higher output than the pickups on the Richie Sambora Strat?

You should know that the Strat has a vintage routed Ash body, maple neck and fingerboard, it is made from high quality parts. It has a vintage synchronised trem that is adjusted to be flat with the body.

Help mucho appreciated so I can finally be happy with my custom project!

Cheers

 

[bert123]

Re: Several Minor Issues with My New Wiring

Having just finished rewiring a strat it looks like the tone control is still wired as it would be for a 2 tone control strat with the 2 controls using the same cap.

Here is a SD 1 Vol 1 Tone Strat Diagram. Looks like you need to swap the tone control wiring (cap to middle, wire to volume on outside lug).

I'm not an expert, that is just what I would try first.

 

[OdgeUK]

Re: Several Minor Issues with My New Wiring

Slight amendment to the diagram required. The cap is actually a 0.047 orange drop cap. NOT a 0.22.

 

[OdgeUK]

Re: Several Minor Issues with My New Wiring

Having just finished rewiring a strat it looks like the tone control is still wired as it would be for a 2 tone control strat with the 2 controls using the same cap.

Here is a SD 1 Vol 1 Tone Strat Diagram. Looks like you need to swap the tone control wiring (cap to middle, wire to volume on outside lug).

I'm not an expert, that is just what I would try first.

Thanks Bert, something to look at. The wiring on the Tone control was suggested to me by the legendary ArtieTOO so I didn't check that!

 

[Artie]

Re: Several Minor Issues with My New Wiring

Note: Read my edit at the end, before you start unsoldering.

Hey Odge; I'm not sure what Bert is refering to. Your tone control wiring is exactly like whats in that diagram he linked to. The only difference is the two lugs are reversed, but that doesn't matter on a tone control. Resistance goes "up" with clockwise rotation, and "down" with anti-clockwise rotation. A normal Strat would have the tone controls wired to the 5-way. Anyway - on to your problems.

Problem #1 is simple, and sorry if I overlooked this when we first helped you with that diagram. A Duncan is opposite polarity to the Fenders. Just reverse the black and green wires from the JB. That might introduce a new problem, although minor. Before you do anything, plug the guitar in, select the JB only, dial in the spin-a-split and then gently tap on each coil with a small screwdriver or something. Note whether or not the coil that you want to be active is, or is not.

If the coil you want to be active is active, then when you reverse the black and green, you'll also have to move the black wire thats on the spin-a-split pot from ground over to where you attach the green wire to the 5-way.

If the coil you want to be active is not active - do nothing. It will automatically become active when you reverse the black and green.

Problem #2 is probably either of two conditions:

a. You're using a no-load pot for the tone control, and the "cut" is made on the wrong side of the carbon trace.

b. When you soldered to the back of the pot, you over-heated the plastic disc that holds the wiper, and now it doesn't touch 'til it gets to the end of the travel.

In either case, the solution is to replace the tone pot with a new one. Wire it up exactly like the old one. Your drawing is correct.

Problem #3 is a little more vague. I'm somewhat grasping at straws here. The fact that you're using a 500k volume pot, added to the tone control failure, means you'll have a very bright axe. This could cause the perception that pups are not "warm and full". I would fix the phase, tone control, and possibly the volume pot problems first, then let us go from there.

Artie

Edit: I just noticed that you say the #2 position is weak also. That implies that only the middle pickup is out-of-phase with the other two. I would reverse its wires first. Then let us know how that sounds before you do anything else. (The tone pot will still be a problem.)

 

[OdgeUK]

Re: Several Minor Issues with My New Wiring

Thanks Artie, you think the middle pickup might be out of phase with the others? even though the black from it is going to ground and the yellow to the switch like the other Texas special?

Regards soldering on the pot, there was no soldering there. All the grounds were crimped together into a ring terminal which was then put over the pot shaft to make contact with the shielded pickguard.

The pots are CTS and came in a pack like this:

I will get the guitar apart tommorow and review it with your suggestions in mind. Cheers!

 

[Artie]

Re: Several Minor Issues with My New Wiring

Thanks Artie, you think the middle pickup might be out of phase with the others? even though the black from it is going to ground and the yellow to the switch like the other Texas special?

I realize that since they are both Fenders, that doesn't make sense, but it matches the symptom you're describing exactly. Just for the sake of "process of elimination", I'd do it just to see. (Reverse the wires on the middle, I mean.)

Regards soldering on the pot, there was no soldering there. All the grounds were crimped together into a ring terminal which was then put over the pot shaft to make contact with the shielded pickguard.

The ideal situation would be to have a meter. Measure between the center and either outside lug, on "ohms", and see if the meter changes while you turn the shaft. Also, measure across the outside lugs and see if you get approx. 250k. (250,000 ohms) Both those tests will help determine which of the two problems exists.

Either way, its an odd problem considering its a new CTS pot. It could be a defective pot. Stranger things have happened.

 

[Artie]

Re: Several Minor Issues with My New Wiring

One more thing - double, and triple-check your grounds. A "lost" ground in one of the switch positions can cause unpredictable results.

All the grounds were crimped together into a ring terminal which was then put over the pot shaft to make contact with the shielded pickguard.

The more I think about it . . . the more suspect this line sounds. Quadruple check those "crimps".

Is the shield foil? :blackeye:

 

[OdgeUK]

Re: Several Minor Issues with My New Wiring

I did check all the pots with a meter before I installed them. I did this out of curiosity to see how close they were to the values they were meant to be. One of the 250K pots was closer to 270 if I remember rightly. The 500K pot was near as dammit. I also put a meter on the middle lug and then each of the outside lugs in turn to see what happened. Depending on the polarity of the meter leads it would give a rising negative result or a falling positive when I turned the shaft. It all seemed ok.

THe crimped grounds should be good. I perhaps didn't explain it well. All grounds came together and I twisted the bare ends of them all into a point. I then fed this point into the neck of a ring terminal and crimped this down to secure. This ring terminal then slipped over the shaft of the master tone to make contact with the pickguard.

The cavity is coppertape sheilded and I measured it at all points for continuity. The back of the pickguard is shielded with heavy duty Aluminium foil.

If all was correct what kind of result would you expect by changing the volume control for a 250K pot? I heard that JB Jrs work better with a 500K pot but that the singles would prefer a 250k!

Bah....confusing old game this wiring lark eh? :laugh2:

 

[Artie]

Re: Several Minor Issues with My New Wiring

The question of the 500k or 250k for the volume pot is very minor at this point. I wouldn't mess with that until we fix the other problems. If you're sure the pots are ok, and the grounds are ok, I need to think on this a bit.

Those were my best shots. :yell:

I'll think . . . you triple-check grounds.

Artie

Oh yeah . . . and do switch those wires on the middle pup. Just to be sure.

 

[OdgeUK]

Re: Several Minor Issues with My New Wiring

Hello my lovelies. Well I finally got round to reversing the leads on the mid pickup and guess what?........it worked!!! I now have a usable sound in both pos#2 and #4. Great advice ArtieToo thank you.

Now, this has left me even more confused. Why would a brand new Texas Special Mid (RW) pick-up need the leads wired in reverse in order to be in phase with the SD JB JR and the Neck Texas Special?? I don't get it!!!

So now I just have a problem with the Master Tone Pot which is a CTS pot purchased in a kit with the tone pots I used for the Master Volume and Spin-a-Split. Both the Master Volume and SpinSplit pots graduate as they are turned down from 10, but the Master Tone does nothing till it reaches '1' and then abruptly kills all the treble. Resistor value?? Dodgy pot??

ALSO....what would be the effect of reversing the polarity of the JB JR at this point? Reversing the middle pickup has pos#2 sound great but pos#4 could sound better I think. Or by reversing the leads of the mid pickup will it always be out of phase with one of the others?

Damn, i really don't understand this polarity business!

Thanks Guys.

 

[Artie]

Re: Several Minor Issues with My New Wiring

I was just heading for bed, but tomorrow I'll look this over and see what kind of semi-intelligent ideas I can come up with.

 

[OdgeUK]

Re: Several Minor Issues with My New Wiring

Thanks Art, looking forward to your wisdom!! It's all really beyond me. I was shocked that I even managed to wire it in the first place! LOL!

 

[OdgeUK]

Re: Several Minor Issues with My New Wiring

bump:bandit:

 

[Artie]

Re: Several Minor Issues with My New Wiring

Now, this has left me even more confused. Why would a brand new Texas Special Mid (RW) pick-up need the leads wired in reverse in order to be in phase with the SD JB JR and the Neck Texas Special?? I don't get it!!!

Poop happens. I think there was a batch of JB's that got out awhile back, with one bad coil - or something like that. It would only take getting the bobbin mounted backwards on the machine for that to happen.

So now I just have a problem with the Master Tone Pot which is a CTS pot purchased in a kit with the tone pots I used for the Master Volume and Spin-a-Split. Both the Master Volume and SpinSplit pots graduate as they are turned down from 10, but the Master Tone does nothing till it reaches '1' and then abruptly kills all the treble. Resistor value?? Dodgy pot??

There is one thing that will cause this for sure - I just discovered this with my boy's Strat - using a linear pot, instead of audio-taper, will cause that exact problem. Put the pot in the middle, and see if it measures about half resistance. If it does, get an audio, (or "log), taper pot.

ALSO....what would be the effect of reversing the polarity of the JB JR at this point? Reversing the middle pickup has pos#2 sound great but pos#4 could sound better I think. Or by reversing the leads of the mid pickup will it always be out of phase with one of the others?

Damn, i really don't understand this polarity business!

Thanks Guys.

Reversing the JB is something you'll just have to try. It may, or may not be out-of-phase. Doesn't sound like it from your description, but you'll just have to try it.

Artie

 

[OdgeUK]

Re: Several Minor Issues with My New Wiring

Thanks again. I'm loathe to 'experiment' too much as removing my scratchplate requires slackening all the strings and, in some cases, removing them and the neck in order to lift the scratchplate out! I probably need to 'modify' my non-fender scratchplate to fit with a 22-fret neck a little better! I don't want to take the neck off and on any more than neccessary!

So, it seems that I may have been unlucky with my Fender Custom Shop Texas Special and perhaps ended up with a reversed polarity pickup! Do you know that this pickup (brand-new by the way from a store in Germany) also had a loose wind? It had been waxed to the top of the bobbin to secure it (presumably by Fender) but it came loose once in my possesion. I never did wax it down again, as it was only one wind. The DC resistance of the pickup measured correctly so I left it as is. Makes me wonder about Fender's quality control, especially considering that the Custom Shop are Fenders flagship. Amazing that this got past whatever passes for quality control! Another thing that is interesting about this pickup is that the pole pieces are staggered very differently to the Texas special in the neck position (which I bought used from eBay). I've yet to see a full set of Specials on a guitar to compare.

And, despite purchasing a Fender pot and switch kit, it may actually have consisted of a mixture of audio-taper and linear pots which I should have identified on a multimeter before installing most likely. Crikey! This is a real learning curve!

I do have one more question.......that 0.047 resistor on the tone pot. If it was a 0.022, what effect would you expect that to have on the tone?

Cheers!

 

[Artie]

Re: Several Minor Issues with My New Wiring

I do have one more question.......that 0.047 resistor on the tone pot. If it was a 0.022, what effect would you expect that to have on the tone?

Cheers!

Actually, its a capacitor. I prefer .022uf myself. It just means you'll only be trimming off the treble, instead of dipping down into the midrange.