guitar wiring

[Danster]

Hey guys,

Well I got a project guitar (kinda by accident). It needed pots, a pickup, and a bridge. The guitar is a little unusual in that it has only one spot for a pickup (humbucker), and it has two holes for pots, and no spot for a toggle switch (understandably). After finding someone who used to own this model guitar, he told me that one of the pots was a volume, and the other was actually a switch (not a pot), which allowed coil splitting and a volume bypass.

Anyhoo, my plan is to wire it such that I have a volume pot (of course) and have a tone pot also which has a push-pull switch that will allow coil splitting. As I have mucho little experience with wiring (especially guitars), I'm going to try to post a wiring diagram, such as it is, to see if you guys think the way I'm wiring it is correct. Forgive the fact that my picture is not a conventional wiring diagram, but is more of a picture, but I doubt I could do the real wiring diagram properly.

Note that I have shielded the cavity in this guitar using info from guitarnuts.com, so some of the grounding is probably a little non-standard. The two squares are capacitors. The 0.22uF capacitor is there due to a suggestion from guitarnuts.com to protect the player from electrocution (don't ask me to explain, see that site). The thingy to the right of the 0.22uF capacitor is a ring terminal which is grounded against the conductive wall of the cavity. The wire extending left from the 0.22uF capacitor going to the tone/switch pot actually goes to another ring terminal at the base of that pot. Hopefully everything else is self-explanatory (assuming the picture actually shows up!).

Edit added after original post: OK, there's a mistake. I have mislabeled the neg and pos output. Those should be reversed. (Sorry, I didn't want to redo the pic ;) ).

Yet another edit: I also forgot to mention that for the tone pot, the low end is the far right terminal, and for the volume pot, the low end is the far left terminal.

[szulc]

This not correct, the hot wire coming from the V pot should be connected one terminal to the right on the tone pot, where the hot from the pickup connects.
Leave the cap on the middle terminal of the tone pot.

[Danster]

Hey James,

Thanks for your reply. I knew you would come through here! I don't have time today to study this right away, as there's the ol' 9 to 5, and then my son is dancing with the Moscow Ballet tonight (!!!), so I'm off to there after work. When I have time to check it out further, I'll get back to you if I have more questions..... which I probably will!

Cheers,
Dan

[Danster]

Originally posted by szulc
This not correct, the hot wire coming from the V pot should be connected one terminal to the right on the tone pot, where the hot from the pickup connects.
Leave the cap on the middle terminal of the tone pot. OK, I've studied this a bit more, and it seems to me that both you and I are wrong. It seems to me that if I made the modification you suggest, then there would be no signal out from the tone pot (refer to my earlier diagram). Isn't that correct? I have modified my earlier drawing, and am posting the new version below. I think in my earlier picture, I ALWAYS had a complete circuit for the hot from the pickup, even when the tap switch was ON. What I need is to wire it such that EITHER the tap wire is live, or the hot from the humbucker (both coils used) is live. So I redid (is that a word??) the diagram to run the hot from the humbucker through the switch also. Willing to take another look James?? or anyone??

BTW, I fixed the + and - for the output in this pic, and the low ends of the tone and volume pots are marked with a "*".

Cheers,
Dan

[szulc]

My previous statment is still correct the way this is shown you will always have the .047 uF capacitor between you hot and ground, this will always be like having the tone control all the way off (lo pass filter). The other problem is your tone control is going to cut your level the way it is shown. The middle terminal on a pot is always the wiper, the ends are each end of the resistor.
With the change you have made it will work when the tone pot is all the way up, but you will have no highs and as you turn the tone pot down you will lose your signal.

I have included a schematic for the correct wiring of a tone and volume control with a Humbucking pickup and a coil tap. You are switching the coil tap to a hot and I think that is more prone to noise than switching the coil tap to ground

[Danster]

Thanks again for helping out James. I must admit that I don't understand circuits well enough to understand why the one you diagrammed should work. . . but I'm gonna take your word for it. :)

One thing I didn't realize before but is obvious from your schematic (and now I see it now that I looked back at my original sources) is that the tone and volume pots are wired in parallel.

Anyhoo, below is another of my pictures. What I have done this time is try to make the changes you suggest, based on your schematic and your explanations. I have obeyed (:D ) and attached the hot from the volume where you suggest. I also did the tap wiring as you suggest (as best as I can tell). Hopefully this is the last version.

Whaddya think??

NP: Genesis: Duke

[szulc]

This looks like it should work. If you have an Ohmmeter you can figure out which physical coil is active on your humbucker. I like to use the coil closest to the bridge for my tapped single coil sound (on my bridge pickup). Connect the Ohmmeter to the output wires of one of the coils set to AC Volts and put it on the lowest range. Now tap the magnet in of one of the coils with a screwdriver and watch the voltmeter, now do the same thing using a magnet (Pole Piece) on the other coil. One of these will have have much greater activity on the meter than the other. That is the physical coil your meter is electrically connected to.
If the pickup has one side of one of the coils already grounded you might need to tap to the hot instead of the ground to get the physical coil you want on when tapped.

[Danster]

All right James. Thanks again for your help. I hope to get around to wiring this thing up in the next week or two.

Cheers,
Dan

[Danster]

I finally got the dang guitar wired up.

I wired it up a couple of days ago according to the latest posted image in this thread, and it didn't work... no life at all. I was cursing James under my breath. So then I unsoldered all the wires and just tried to wire it without coil splitting, using the simplest circuit I could do.... still nothing. Then I really got serious, and went straight from the pickup wires to the output jack, taking the volume and tone controls totally out of the loop... still nothing! At this point I was wondering if I had fried the pickup (the guitar only has one) with my messed up wiring. Well, I took a second look at the output jack, and, um... :o well, there ARE six terminals on that damn thing. You couldn't tell by looking what was what, and I had checked them with an ohm meter, but before I got around to soldering, my brain switched what was what. Long story short (OK, too late for that :D ), I had attached both output jack wires to ground terminals (I had to apologize to James under my breath :D ). Then I wired it up again like in the pic. Everything seemed to work fine except the volume pot worked backwards. I switched the outer terminals and then that worked fine.

Tonight I put the bridge on it. I had had to get some machining done on it (which is another long story, but my rule is one long story per post :D), and hadn't had it on the guitar before. (I was checking the wiring up to this point by touching the pickup magnets with a screwdriver to see if they were live.) The bridge is a Floyd Rose type, which I have never messed with before, and it took me a while to figure out how to make it work and to get it tuned properly. The guitar works great now, except for two things. One is the tone control works backward (I suppose I'll fix that by swapping the connections to the outer terminals. I couldn't tell anything about the tone with my screwdriver testing before). The second thing is, I had radio coming through my amp again, and this time without my Dano pedal attached!! It didn't last long, and was not coming through strongly, but I thought that was weird. I did shield the cavity in this guitar, but I'll have to see if that continues to be a problemo.

OK, you can all relax now that you've gotten my story. I know you were all waiting with baited breath for this update (what the heck is baited breath anyway? :rolleyes: )

[szulc]

If you actually wired it the way it is shown in the drawing (assuming this view is from the back of the pots) it should have worked correctly and the volume and tone post should have been full up at the clockwise most position. On your shielding, did you solder a ground wire to your copper foil in the cavity and to the foil on the back of the pickguard or cavity cover? You need to.

[Danster]

Originally posted by szulc
I you actually wired it the way it is shown in the drawing (assuming this view is from the back of the pots) it should have worked correctly and the volume and tone post should have been full up at the clockwise most position.In my second pic, I labeled the low terminals of the pots. I failed to label them in the third pic, but they are the same as in the second pic. Sorry bout that, but I confused matters I suppose by my pic.

On your shielding, did you solder a ground wire to your copper foil in the cavity and to the foil on the back of the pickguard or cavity cover? You need to. [/B]The ring terminal in the pic is held down by a screw which connects the ring to the aluminum (its aluminum foil, not copper). I put foil on the cavity cover and it makes a connection due to contacting the foil in the cavity. One thing I didn't do was to shield the actual pickup cavity (on the front of the guitar, whereas the cavity for the pots is on the back).

The coil splitting works great, and thats a cool thing.

[szulc]

(what the heck is baited breath anyway? )

I don't know but it sounds like listerine should help!