led brightness on signal pot

[birt]

if a pot is used for something signal related, let's say a wah pot, can it be used to controll a dc level at the same time to make a led/lamp shine brighter as the pot is turned up?

i mean, signal and dc are both controllable by a pot. now if i put decoupling caps before and after the pot, there will be no interferance in the signal by the DC and i use one pot for 2 purposes.

[darron]

you could use a dual pot?

[birt]

yes but it's hard to put a dual pot in a wah when it's made for a single pot

[GibsonGM]

Interesting, burt...good idea, but maybe not being approached the right way.  Caps always leak some DC...if you do this in conjunction with an audio signal, I bet it would degrade/otherwise impact the audio.  Something would mix between the 2 "stages" in the same pot,and add in leakage, changing voltages,  you know?  Not a good idea to try to use pots that way, generally speaking.

However, I'm willing to bet there IS a way to make the LED get brighter/dimmer with the setting on the wah pot and not use a dual.  Possibly related to using a transistor or op amp somewhere on the pot output as an amplifier, feed some of the outgoing signal into the base or OA input as a control signal (involving filtering, make it freq. dependent), maybe?  Or, do the mod to the wah to replace the pot with an LDR; then the signal would be isolated and you could mess around.   Another way could use the same idea of a freq. dependent opamp, just tapped into the pedal output (more gain with higher freq's, less with lower....this actually sounds promising).  Just some ideas that came to mind, maybe I'll give this one some thought later, too...good luck!