Vactrol-based Expression pedal board

[kragg]

Hello,
I post a layout i made for a daughter board allowing to use an expression pedal input on a circuit as a replacement of a potentiometer. The board use a vactrol.

The layout is supposed to be a veroboard version of this schematic from Zokk :




I build it, but didn't yet put it on a circuit, so it's still unverified for now.

[Mulekicker]

This is very cool. Wonder how it would work controlling the frequency pot on something like the ESR Graphic Fuzz. Hmm.....

[kragg]

It's good if it can be useful.
Please let us know if it works for you ;)

[andrea83]

Thank you for the schematic! I've been looking for this kind of thing for a long time.
I made a layout before seeing yours. Hope it can be useful!

[andrea83]

it's not verified and maybe yet to check

[kragg]

Thank you, Andrea.

[andrea83]

Thank you!

[kragg]

I didn't do much. All credits go to Zokk (link above).
By the way, I am struggling to make it work as it should, so i would be curious to know if anyone manages to make it work (I don't knkow if it is my layout, or the homemade vactrol, or the wiring, or the circuit, or the pedal, or setting the trimmers correctly, or...). In theory, the layout seems ok, but as it is an "interactive" design (where several parameters can have an impact on the main circuit purpose), i don't know where the issue comes from.

[mercury6]

seems simlilar to the synthrotek vac pac. if it don't work why not just do a layout for the vac pak. they have schematic on there site. and great work. this is awsome