Series/Parallel switch WITH blending

[RyreInc]

Everybody seems to think that you can't have blending when your pickups are in series. However, I've drawn out a schematic that will allow one to have a series/parallel switch that still uses the blending pots when in series mode.

In this picture, the first circuit is the one with switching that you should follow. The second two circuits show the results of the switch in each position.
The numbers indicate that a wire should connect from the switch to that point--all drawn wires remain intact.
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As you can see, the volume pots are basically considered as part of the pickup, and are incorporated into the switching.

Let me know what you think!

 

[RyreInc]

Note that in series mode, the volume pots are in parallel with the pickups, and act as a shunt resistance; the pots never place any resistance in series with either pup.

Also of note is that in series, the wire connecting pot1's upper contact with the hot is redundant, and can be removed if hardwired--the wire does not affect the output, and remains only to facilitate switching.

 

[bongomania]

Interesting! Have you tested it in actual use?

 

[Dr Illing]

My Warwick $$ blends in series mode.

 

[RyreInc]

I haven't been able to test this yet unfortunately--my only bass has a blend that is attached to a PCB board, so I don't want to mess with that (yet). However, I do plan on trying it on my guitar when I re-mod it soon.

I'm glad to see there is something else out there with this option.
Dr Illing, do you know if the blend is a passive or active circuit?

 

[ChenNuts44]

Did you draw that in paint?

 

[RyreInc]

Did you draw that in paint?

I used PSpice actually

 

[PawleeP]

any diagrams.. I could use a good one for wiring a jazz series/parallel..
any help appreciated.. p

 

[RobbieK]

I've found that a simple 500K linear pot works ok as a blend for a couple of jazz singles wired in series. You have the series join (where the hot from one pickup meets the earth of the other) connected to the centre lug and the outer lugs connected to hot and earth. The trouble is, that because the series pair are louder than either of the singles, there's a volume swell around the middle of pot sweep. If that doesn't bother you, then yeah, that's an option. I took that further and used a dual gang pot B500K and used the second gang to attenuate around the middle of rotation to even out the volume. There's a thread about this from a couple of months ago.
It works well...


A 250K MN (blend pot) can be wired to work as a (single gang) B500K. So theoretically you could switch from series to parallel and keep the same pots. You'd still have that volume swell issue though of course. And you'd need more than two switch poles, so a push-pull isn't going to work. I'll try and get some diagrams together later on. It should be doable with a 4-pole switch, so a cheap mini toggle would work I think...