Knobs & Pots Question

[Mikhail]

After seeing Dan Howard's Carl Radle inspired Tele/P-Bass project I'm planning on a similar build of my own. What would I need to do to keep the appearance of the bass the same, but have separate volume and tone controls for each pickup? I'm aware of concentric knobs, but quite frankly I'm not very knowledgeable as to their workings. I checked out Buzzard's Bass Shop's website after a Yahoo search and found this:

Concentric Stacked Control Knobs at Buzzard's Bass Guitar Shop

Would I need any special pots or other electronics to make this work? I'd appreciate any advice or feedback. Thanks.

[line6man]

You need concentric pots.
Treat each layer as if it were a separate pot in whatever diagram you are following.

Why do you want two tone controls, though? They are going to interact unless you isolate them with resistors, and doing that will give you a volume drop.

[Mikhail]

I just assumed that it should be laid out that way, like a Les Paul where both pickups get a volume and a tone. I'd like the pickups to function independently; did the Jazz Bass have a stacked volume control and a common tone control? How does the layout work in the P/J? What kind of interaction happens? Thanks.

[line6man]

Originally Posted by Mikhail

I just assumed that it should be laid out that way, like a Les Paul where both pickups get a volume and a tone. I'd like the pickups to function independently; did the Jazz Bass have a stacked volume control and a common tone control? How does the layout work in the P/J? What kind of interaction happens? Thanks.

Originally, Jazz basses had two volumes and two tones, but Fender quickly changed that to a master tone.

When you have two tone controls in a passive setup, when the volumes are both up, those tones run in parallel, so they both act as masters. Early Jazz basses with the stacked knob configuration often had 220K resistors in series with the output from each pickup's volume pot, so that the tones would be independent, but this series resistance means a loss of output to some degree.

It works with Les Pauls, because you have the pickup selector switch. You can have a different setting dialed in for each pickup when you solo them, but if you play both pickups together at full volume, the tones still interact.