How to add an always on passive tone control to Aggy OBP-3?

[stflbn]

How would I best add an always on passive tone control to my existing 5-knob Aguilar OBP-3 install?

The install is a bit more complicated than most.

Bass has custom Kent Armstrong humbuckers in it.
Neck Vol (push/pull for series/parallel)
Bridge Vol (push/pull for series/parallel)
B/M/T (mid is hard wired to 400hz)
Active/Passive switch

I plan to move the Treble and bass onto a stacked knob and the passive tone taking the place of that knob.

Any thoughts or diagrams as to how best accomplish this with this setup? I've really come to love the always on passive tone on my custom Regenerate bass as well as my Fendowsky and miss it when I'm playing my other basses.

[line6man]

You can simply connect the third terminal of the tone pot to the first terminal of one of the volume pots.

[stflbn]

Not following... what if I've solo'd the other pickup's volume pot?

[line6man]

Originally Posted by stflbn

Not following... what if I've solo'd the other pickup's volume pot?

They share the same output, don't they?
The first terminals of both volumes should be connected together.

[stflbn]

Yes.

There's a blue wire from first post of both stacked Vol pots that then goes to the first post of an active/passive 2-way switch.

So the tone pot would potentially go in between the Vol pot and the active/passive switch then?

[line6man]

Originally Posted by stflbn

Yes.

There's a blue wire from first post of both stacked Vol pots that then goes to the first post of an active/passive 2-way switch.

So the tone pot would potentially go in between the Vol pot and the active/passive switch then?

Yep, that works.

[Jefenator]

The active Dingwalls have a treble knob setup that sounds like a fantastic idea: active boost & passive cut on one knob. If I were doing an active rewire, I would absolutely love to do this.

I assume it uses a dual pot of some sort w/ center detent. (Wondering if a readily-obtainable blend pot could possibly be made to work, or if it's a custom dual-value unit not worth the $$$ in small quantities.)

[FunkMetalBass]

TS, you're going to connect both wires to the single pot before the Active/Passive switch, and wire it up like a normal tone pot.

Alternatively, you can run the preamp out and the passive out to the same pot, but that will give you considerably different results.

[line6man]

You don't want the output of the preamp going into the tone control, because the preamp has a low impedance output.
The tone control needs to go before the preamp.