Jazz Bass Stack Knobs

[Uncle Vinnie]

Is it doable to convert a stack pot Jazz Bass to conventional 3 pot set up using the existing harness?

 

[strayedstrater]

Not exactly sure what you mean by using the existing harness? Using the existing 2 dual concentric pots to do vol/vol/master tone (1 of the pots not used)?

Yes, that's possible. Two dual concentric pots are electrically the same as having 4 separate pots.

 

[Cozmik Cowboy]

Yes, that's possible. Two dual concentric pots are electrically the same as having 4 separate pots.

But how would you adapt the 4-pot wiring to 3 pots.

 

[strayedstrater]

Yes, but with the 4 pots of the stack knob, you don't have to use all four. You could wire 3 of them to work like a 3 knob Jazz. What I was saying is the 4 pots are fully independent and there's nothing tricky about using just 3 and leaving one totally non-functional/unconnected.

Like I said, I'm not clear exactly what Uncle Vinnie means by "using the existing harness" -- to fully convert a stack to a 3 knobber you'd replace the pots, knobs, and mounting plate.

But a lot of people prefer the function of the 3 knob master volume instead of individual tone controls, and you can get that using the stack knobs if you don't care about not using all 4 pots. That way you maintain the vintage cosmetics but gain modern functionality. And you don't have to spend any money on pots, knobs, and a mounting plate.

 

[strayedstrater]

But how would you adapt the 4-pot wiring to 3 pots.

Stack knob Jazz has 4 pots. He wants to convert stack knob to work like a 3 pot Jazz.

So the 2 center knobs remain as neck and bridge volume. One ring knob will work as the master volume, the other ring knob won't do anything at all.

The ring knob that you don't want to use -- disconnect the jumper wire between the volume and tone pots, add a wire to the same lug on the volume pot and run it to the other tone pot (to the same lug on that tone pot that's connected to its stacked volume pot).

 

[CB91710]

Do you currently have a 2-pot stack with separate volume and tone for each pot, or do you have the 3-pot stack with the active preamp?

The original 3-pot design is simply 2 volume and a master tone. The pickup hot leads are connected to the wipers of the volume pots so running either to "0" doesn't kill the output like a LP in the middle position.