Modify PJ wiring to bypass bridge pickup.

[bdplaid]

Thanks, but I want to bypass the pot, specifically. I'm trying to change the total resistance of the circuit to 125K. If the pot stays, it remains what, 83K? Which affects the tone of the P.

I'm using Jazz wiring for the VVT. I suppose if I make the output wires of each vol pot a separate wire, rather than jumping from vol 1 to vol 2 as in the std J wiring, I can better do this. But I was looking for a more elegant way to do this.

 

[bdplaid]

Oh wait, I think I see that this diagram shows that? Tough morning! But I can't just cut out the signal after Pot 2, because it will cut out the entire signal. right?

 

[Crater]

But I can't just cut out the signal after Pot 2, because it will cut out the entire signal. right?

I've been mistaken before. Better take it to a tech, just to be safe.

 

[bdplaid]

I've been mistaken before. Better take it to a tech, just to be safe.

View attachment 3548178

Nah, it's not like it'll burn down the house or anything. ;-)

 

[bdplaid]

I've been mistaken before. Better take it to a tech, just to be safe.

View attachment 3548178

The diagram looks right, the problem I think is that not precisely how it's wired. It's like this:

So if I'm reading it right, interrupting the signal anywhere along the hot wire interrupts the entire signal. I need to figure out how to bypass the interruption with the P pickup. I know this has been done before, I just can't find it.

 

[bdplaid]

PJ Wiring Question about Jazz Bypass

 

[Crater]

CLUE: Post #21, second paragraph, second sentence. Fender wires J-basses that way (jumper wire between the neck and bridge volume pots) because it saves them 4" of hookup wire per bass.

 

[Axstar]

But yeah, the quirk of VVT wiring is that the vol pots are wired the wrong way around (kind of), unlike any other volume pot not just in basses, but in amps, hifi, pedals, etc etc. This I'm guessing was Leo Fender's idea and it is actually quite a creative solution to improve the Jazz bass circuit. (The original 60's VTVT circuit was far from ideal.)

It is a ruggedly economic solution that works! The two pickups are wired to the wipers of their corresponding volume pots. The resistance of the pots stops them from interacting with each other. The tradeoff is that you quickly shed treble when you turn down the volumes.

The stack-pot Jazz basses had fixed resistors on the output of each volume pot to stop the controls interacting. It worked, but at the cost of output. People reckon that the stack-pots sounded sweeter, and you could make it a switchable feature in your bass circuitry simply by switching a fixed resistor in series with the output of the two volume pots.