Walmartyr wrote: ↑
Wed Dec 02, 2020 11:28 am
Hello! It seems I've stumbled across fellow enthusiasts, and was wondering if I could pick your brains.
I would highly appreciate if somebody could check my work and make sure that this schematic would do what I want it to do. I'm looking to swap out my Novak JM-180 with a Novak JM-WR. I'm trying to teach myself basic electronics, and I'm sure there are a lot of embarassing mistakes here...
What I'm trying to achieve:
1) Coil Tap on the JM-WR going to the top circuit, which only engages one pot for Dial-a-Tap: fully tapped at 0, fully untapped at 10.
2) Rhythm Pot for Neck Pickup (wired like original Rhythm Circuit), bypassed at 10 and full on at 0. (not super crucial, but would be nice)
3) Ability to access tapped humbucker plus Neck pickup in the middle position on the 3-way switch.
Also, half of the top DPDT switch is unused. Do you see any recommendations on how to utilize it?
Here's a copy without drawn wires, if desired:
https://shared-assets.adobe.com/link/4c ... b2c667c315
I find this a bit confusing, but I think I've worked my way through it. You haven't drawn out a ground connection from the jack anywhere else than the back of the tone pot, so for that to work there needs to be some kind of conductive material on the back of the pickguard (as it were) to connect to the rest of the grounds, which are connected to the back of the volume pot. If that's there, then we can get past the gate. Or then you intended to wire the jack negative to the back of both pots and the rest of the groun wire to the pots?
As for the wiring, this needs a bit of explaining and some rework.
Master Tone: this works.
Master volume: with the suggested wiring, this would do basically nothing. You need to move the wire that connects the volume and the output jack to come from the middle potentiometer lug instead of off to one side, so the signal is forced through
the potentiometer. Also I believe audio instead of linear pots should work better, especially once you have a treble bleed, but you'll need to test this to see what you like.
Bright switch that wasn't mentioned: should work, you should probably check the value for the capacitor once you're good with the rest of the wiring.
As for the rest, I'd need a bit of clarification. If you'd wire the pickups directly to the selector I think we should have a working guitar with the above fixes.
Bridge pickup: What does the third wire of the Novak JM-WR do (purple)? Most humbuckers either have two wires or four wires, but three would typically mean that you might not be able to do other things than to get the full output and then some kind of half-output, or single coil of a humbucker or the like. Meaning that wiring this to the dpdt toggle switch means you'll always do something, as it goes to ground all of the time, through a pot or not. Which means that if wired like this you essentially would always only get the "single coil" sound if that's what it does, or then something to that extent through the pot in the other position.
You say it's a coil tap, but does that mean that the tap should be connected to ground or become the tapped hot lead?
Neck pickup: The hot out from the neck position here goes to a pot beside the dpdt toggle switch. As wired like this I believe it should act like a separate volume pot only for the neck pickup, with a hardwired low pass filter like a gretsch style mud switch (eg. the same thing you roll in and out with a tone pot). Might be a cool sound, but might not be what you had in mind? (I really like the mud switches on neck filtertrons, haven't tried on JM pickups).
Stick to it, I think we can work this out!