I hope you can help, I'm trying to work out a wiring harness for my first CBG and I have zero knowledge and understanding of such things!
I've had a good look at the wiring schematics posted here and they're very helpful but not quite what I need. I want to wire a coil pickup and a piezo via a three way switch. I want a tone control on the coil and one master volume for both pickups.
I've found the diagrams on the site for piezo and coil together but each pickup has an independent volume control and I haven't got the space on my box for three pots. Is such a thing possible?
Any advice would be gratefully received!!!
Ted is a wizard with wiring and probably has a diagram here somewhere. What I would do is wire the coil and piezo to the three way switch directly and then wire the output from the switch to a single volume pot and from there to the jack. Can't draw you a diagram so I don't know if that helps or not.
No time to use my office computer and fancy images so I drew up the wiring diagram you asked for in the shop while having a beer break.
* * B E W A R E * *
I would never wire it this way because of the huge output difference in a mag pup and a piezo. The mag will overpower the piezo, plus I like the option for independent volume controls. It WILL work for one or the other at a time though. I would find room for a second volume control, or possibly a stacked pot for vol/tone, or a blend pot instead of the 3 way. Or, eliminate the 3 way and put the 2nd volume there. Or, find another spot for the knobs & switch, maybe on the side of the box that faces you when playing.
* I use Gibson style 3 way switches.
(OOPS, I forgot the neg from the mag to the tone pot and an optional bridge ground to the neg leg of the jack)
I do it this way:
No room for knobs & switch? Get creative. This is a guitar/bass stereo hybrid CBG. Single bass string/vol/tone/separate jack. Neck & bridge 3 string mag pups each with vol/tone thru a 3 way and out thru their own jack.
EDIT: I put sound holes on that Double Trouble git on the edge that faces up to you
On my Jagged Edge build I mounted the controls on the side - 2 Stonehenge 3s (hum cancelling), 3 way switch vol/tone for each, piezo with volume & on/off switch.
I could not possibly offer better advice than Ted did above. That's a virtual mini-encyclopedia of exactly what you're looking for. I will especially second his advice on "get creative". I've taken to mounting volume and tone controls on the top (side) of the guitar box, because there's usually plenty of room up there (unless it hinges in the center). As he shows in the photo, you can also mount them on both sides of the neck.
One other thing to consider if limited on space is wheel-pots. They're flat, they're thin, they come in various sizes and strengths, just like regular pots.
Dang Wayfinder, wheel pots been on my to-do list waaay too long...
Gotta love old Teisco & Airline gits...
(first guitar was new in the 60s - a Teisco Del Rey with sliding switches and matte/shiny striped chrome pickguard. And matching amp from the local department store. Worth a lot today.
edit original answer w/2 more pic ideas