active passive switching... volume pot? 50k/500k

[Jeroen914]

Got an ARTEC pre-amp the other week
Tested it on a J-style bass and it's working fine

Plan how ever is to run it in a different configuration:
Single pickup with an added active/passive switch (and possibly a passive tone control)
So I'm ditching the balance-pot
Signal from the single PUP goes into the pre-amp where the balance pot used to go
(bottom left on the printboard in the pic)

Thought I had this all figured out so far, but...
Turns out the volume pot is only 50K AND runs through the pre-amp
So by-passing the amp would also mean by-passing the volume control
And figured in passive mode I'd need to run a 500k volume pot

Can I put a 500K volume pot between the PUP and the amp, then the active/pasive switch and jumper the original volume-pot (middle right on the printboard)?

Other solutions or ideas?

Thanks!

 

[ctmullins]

I sometimes wire my instruments with an active/passive switch, such that the passive mode is an emergency fail-safe mode. The normal mode is active, in which all the controls work. But if something goes wrong, switching to passive just puts the pickup straight to the jack, with no controls. If this happens (and it did once!), the switch becomes an on/off switch.

Your other option is to wire the pickup into a 500kOhm volume control, then to an active/passive switch, then into the preamp, and don’t use the 50kOhm volume control that came with it. This lets you have a volume control in both modes. But since nobody actually adjusts their volume controls, this seems academic to me....

 

[rojo412]

@ctmullins said it with the second option.

Most preamps basically operate with a signal in and a signal out. Looking at the wiring you posted, the "signal in" comes from the balance control and the "signal out" is adjusted by the volume, but somehow makes its way to the jack.
- Putting a 500k volume (and bypass switch) before the preamp will definitely get you a signal that can be used active or passive.
- You may need to figure out how the existing volume is channeled after the preamp and before the jack, but either you should be able to remove it and the signal won't have that option to be grounded (via the pot) or you send the signal from the previous input to the old pot to the full-time output of the preamp (which would end up routed to the bypass switch anyway).