Old volume pedal on light bulb, suggestions needed

[hilbi]

I have an old volume pedal wich is working via a light bulb and an optocoupler. It is not working anymore. I would now like to use to create a different pedal from it. Any ideas of what to make, it needs to use a light bulb.

[Mike Burgundy]

With a pedal like this, volume and wah functions are most common.
Morley wah's work with a lightscreen - LED combination, even their Vox-style ones. Also, see if you can find Graig Anderton's scratch-free wah retrofit: it's in his book I think and also uses LEDs and lightscreens. I think RG has something up at GEO too (www.geofex.com)
There is no specific need to use a lightbulb, LEDs are easier, sturdier and last waay longer. A LED/LDR (light-dependant resistor) combo can with some tweaking replace most pots, so there's loads of options. Want a wah? Build a wah.
Want a volume pedal? Probably easiest to replace the bulb with a generic bicycle bulb which is probably what it is.
want a distortion with gain settings in the footpedal? Build a distortion, select a handy LDR and use that instead of the gain pot.
Steve Daniels (smallbearelec.com) has a nice selection of suitable LDRs. Which one you need depends on the project at hand.
hih

[fixr1984]

Out of curiosity where did you come across that?  Did you make it. I came upon a stash of thes NOS.
They are still wrapped in the bags, and im trying
to figure exactly where they came from.
I've been swaping out the light with a LED and having pretty good results as a volume pedal.
I built Tims Idiot wah and put it in there but not very useful. The sweep sucks. With a 100k pot the circuit worked good
but for some reason the with the optical setup there isnt enough resistance change to make much difference.

[hilbi]

I just got it from a friend, who got it from another friend, so i don;t really know where it is coming from.