Wiring diagram - 2 humbucker VT+V with some quirks

[Seashore]

I decided against modifying my Gibson PCB, and I'm going to wire this up instead. The guitar is an LP which has 3 pot holes and one 3 way mini toggle in place of the 4th (where bridge tone would be). I'm going to move the pickup selector down to the mini toggle. Neck pickup will have vol+tone; bridge pickup will have vol only, on a push-pull pot so I can keep the volume pot out of the signal path if I want to. This bridge pickup sounds fantastic wired straight to the jack and I wanted to preserve that tone while adding controls.

Initially I had thought to have a master tone control and make the push-pull a true blower switch from bridge pickup to jack, but I realized I want to be able to use the pickup selector even when the bridge is bypassing its volume, and I like the idea of the neck having an independent tone. No tone control for bridge is fine by me. I have the wires to the volume wiper and output lugs reversed from a "normal" diagram so I can use the volumes independently in middle position. I suppose it would be simpler to just bypass the bridge volume entirely and have the neck VT on one side of the pickup selector and the bridge to the jack on the other, and I would only be giving up a bridge volume that I probably won't use, but I have the pots for this already.

I have some questions - will 50s tone wiring work like it's supposed to on the neck (preserving highs when I roll off volume) even though I have the output and wiper lugs reversed? Is it ok for me to skip grounding to the chassis of the push-pull, and instead just wire the pickup grounds to the lug and jumper that to the other grounds? Is there anything I'm missing here that I should think about before I start wiring everything up? Thanks!

 

[Artie]

A couple quick notes: (It's still pre-coffee to study the whole diagram.) When both pickups are selected, the tone control will affect both pickups. There's just no easy way to isolate one control from another with a passive mixer. Even if you use "independent" volume pot wiring. Also, it will still be a good idea to ground the push-pull. It doesn't have to be the "star" ground, but it does have a convenient grounding tab at the top.

And don't forget to ground your tone pot. It isn't shown in the diagram.

With the pickup selector in the middle position, the neck vol/tone affects both pickups even if the bridge "blower" switch is on.

With the blower switch off, both volumes, (and the tone), will affect the bridge pup.

 

[Seashore]

Thanks so much Artie. Really really appreciate you taking a look at this and maybe saving me some wasted effort.

Couple things - the bridge and neck volumes won't be quasi-independent even though I've got the wiper and output lugs reversed? Is there a different way to achieve this without buying a dual ganged pot like you mentioned in another thread? I have a guitar and a couple basses wired up this way (although without tone knobs) and they work like independent dual volumes in middle position, which is what I would want... there's a sweet spot with the bridge on full and the neck rolled off slightly.

No conveniently located grounding tab on my push-pull unfortunately - unless I can use the little tab just to the left of the washer in this photo?

 

[Artie]

Couple things - the bridge and neck volumes won't be quasi-independent even though I've got the wiper and output lugs reversed?

Yes, that will work, but you must reverse the black and blue wires on your neck volume pot in your diagram.

And yes, that PP doesn't have the convenient grounding tab. You could either use the side of the case, carefully, or use one of those star washers that has the solder lug on it.

P.S. With the independent volumes, both pups will see the load of both pots when the pickup selector is in the middle, regardless of where the pot is set. So 500k pots will be seen as 250k. But again, only when both pups are selected.

 

[Seashore]

Yes, that will work, but you must reverse the black and blue wires on your neck volume pot in your diagram.

​​​​​​Ok, I'm confused - when I've done the quasi-independent volumes before, I have wired them up like in the drawing above, with the pickup "hot" wire connected to the center lug of the volume pot rather than the outer lug. There was this thread a little while ago where you recommended doing it that way for someone else who was experiencing the behavior I want to avoid (where either volume would turn down both pickups in middle position).

I'm definitely not an expert on this stuff and I don't know what I'm missing... Thanks again for sharing your time and knowledge.

 

[Artie]

You're right, you're right! I said I was pre-coffee. Your diagram is good. :banghead:

 

[Seashore]

Awesome, thank you Artie, you're the man.

 

[freefrog]

Pre coffee too here, but in my cloudy mind of the morning, independent volume won't let the tone pot work as with "normal" 50s wiring.
5spice sim below. Independent volume makes the tone pot behave half way between 50s and modern wiring... It lowers the volume but doesn't shift up the resonant peak like regular 50s wiring does.

FWIW. HTH...

 

[Seashore]

freefrog Thanks for that. I'm about halfway done wiring it up, so I'll stick with the plan and hear how it sounds. But depending on how much I like it (and considering how little I use the bridge volume), I might simplify this a lot by just bypassing it entirely, going right to the switch, and having V + 50s T for the neck only.

 

[Seashore]

The tab circled here in red is indeed a good grounding tab. I saw a similar one used for grounding on the PCB I removed. I ran a little jumper wire to this tab from the ground lug, and then wired the lug to the rest of the grounds. Works great.



I went with the diagram in the OP (plus grounding the tone pot) and I'm really enjoying it so far. Pickups are Bare Knuckle Warpig neck and bridge (I used Duncan colors in the diagram for convenience, but BKP series operation is red/hot, green+white/series, black+bare/ground). Pots are CTS 500k from mojotone, ​​​​​​tone cap is a .022uF orange drop. I've been using the bridge pickup for a while now but this is my first time installing the neck pickup. Whoever sold it to me didn't tell me that the threads on one of the tabs were stripped, so there's a nut holding it in place under there, but it's fine... I'm not mad. Great pickup. Love this set. Honestly it might be turning into my favorite BKP set.

There are a lot of great sounds in here. With the push-pull down and the switch on the bridge, it's the gnarly hardwired sound I love for this pickup. The neck volume and tone interact in an interesting way. I can get the volume down pretty low to clean up on my gain channel, and when it's down that low the upper range of the tone seems to act as a fine-tuning volume to get it even cleaner, all without ruining the high end. It almost gives me two channels on the guitar, without any of the muddy compromise tones I'm used to. "Smooth" leads, with the neck vol up and tone all the way down, bloom nicely and still have a little bite to them. Middle position is clear without being too scooped, and the independent-volume sweet spot with bridge up and neck rolled back slightly gives it a gritty midrange push. In short, I think I need to rewire a couple of my other guitars.

I have yet to find a use for the bridge volume rolled back to any degree, and I think I'd probably be fine bypassing it entirely (which would have been cheaper and simpler). But man, that pot is nice. It turns with a little more resistance than the others and the push pull action clicks into place firmly. Maybe I'll put it in my Epiphone, that guitar might benefit more from having a "blower" pot.

I put black chicken head knobs on so I can see where I'm at more quickly, and also because I really like chicken head knobs.

 

[freefrog]

The neck volume and tone interact in an interesting way. I can get the volume down pretty low to clean up on my gain channel, and when it's down that low the upper range of the tone seems to act as a fine-tuning volume to get it even cleaner, all without ruining the high end.]

As shown by my sim, connecting a lowered tone pot at the output of an independent volume control lowers the volume and scoops the mids without shifting down the resonant frequency as much as modern wiring would do, so your experience seems logical. A cleaner sound is potentially easier to obtain with the low parasitic capacitance often exhibited by hand wound PU's like BK's, furthermore.

But enough ramblng: let us know if you do other mods and anyway, enjoy!