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Weird wiring schematic question

So i had this cigar box guitar that had a slightly warped neck so i decided to turn it into a lap steel. I also decided to add a hand wound magnetic pickup (as well as the piezo) Someone suggested a stereo jack and cord so that each pickup could be run through separate effects. Not having that stuff on hand, I decided to go with two separate jacks. I started out with wiring that looked like this. But I wanted to be able to run both through the same jack if I wanted to, so I added a switch

The idea being that they could still be run through separate jacks, or with the flip of a switch both through one jack.

However, now the volume controls work in tandem. One won't work unless the other is turned up a little bit. Everything is working all goofy now, whereas individually they both worked fine. Any ideas on how to make this work? I know it's kind of a ridiculous idea to begin with, but now that I've got it started i want to figure out why it won't work and learn how to make it work.

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Permalink Reply by The Phrygian Kid on July 28, 2012 at 7:26pm

Hey matt havent seen you aroun these parts for quite a while Remove the ground from the volume control for the pizzo and it'll work fine.
You could replace one of the jacks with a switching jack, so the switch you put there is automatic, sets itself by virtue Of the presence or absence of the second cable, I did this on a double neck couple years ago. Pickup looks great, nice job.

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Permalink Reply by Matte Resist on July 29, 2012 at 11:42am

That's a great idea (about the switching jacks) but I already drilled for and installed a switch.

What do you mean remove the ground? Do you mean go directly to the tab instead of grounding to the pot?

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Permalink Reply by The Phrygian Kid on July 29, 2012 at 3:30pm

Just lift the ground off that pot. Solder the black from the pizzo directly to the jack, thereby using the pot as a variable resistor rather than as a voltage divider. (you can still leave it onThe pot chassis, this shield the pot, just clip it from the third tab on the pot..

What's happening is this.. When you have one of the pots on zero the other pup is encountering almost zero resistance in following that path to ground.

Another solution woul be to use a pair if diodes (one for each circuit)..

Ps plenty other uses for that hole you already drilled a tone control for the mag springs to mind ;)

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Permalink Reply by Matte Resist on July 29, 2012 at 7:08pm

Thanks! I'll give that a try.

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Permalink Reply by Bad Finger (Eric) on July 30, 2012 at 2:28am

I believe this solves my wiring problem. I guess "when in doubt, ground it out" doesn't apply.

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Permalink Reply by The Phrygian Kid on July 30, 2012 at 3:11am

*if I was doing this circuit FYI id use a balance pot in one of the holes and a ganged pot for a master volume in the other. It might seem more complex, but in the playing it will make more sense. A balance pot ensures at least one of the pups is on 'ten' or up full. The ganged master volume act as for both outputs one the one knob...

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Permalink Reply by Eli Martin on February 3, 2014 at 1:30pm

Oh man this thread is EXACTLY what I have been needing to find! Also Hey, new to the forum. I have a similar idea for blending a piezo and magnetic pickup but only going to a mono output jack. Can I do that with just the balance pot? If I wire the piezo up to the jack as described above? My Idea is to blend a magnetic pup and a piezo for my acoustics and just keeping the pots tucked away in the body of my guitar and have the sound guy adjust the volume or use a volume pedal. Anyway great thread super exciting!