I'm thinking of doing this to try and emulate the ramping of a rotating speaker. Not exactly trying to nail the Leslie tone, but like the idea of adjusting the chorus rate on the fly and think I could use it musically. I already do a trick with the Detune on a Whammy with a chorus.
I don't think mounting the PCB in a shell would be the problem. I was thinking of building the Tonepad Chorus to CE-2B specs, and using the expression pot for the rate.
http://www.tonepad.com/getFile.asp?id=101
My question mainly involves the pot. From my experience with wah pedals, I've never really liked linear taper. I've used ICAR taper pots and thought those worked great in wahs, but if this circuit calls for a 100K linear taper, is that what I should use? Linear, reverse audio, ICAR? I suppose no matter what, the range is going to be limited and I'll just have to adjust the sweep.
This is going to need a bit of testing, I would be quite happy operating this as a "brake" so toe-down makes the effect slow - linear taper is probably not going to do any good here, operate more like an "all on" rocker without enough even sound through the taper... but taper doesn't make any difference to circuit in this sense - just swap the same value A for same value B.
Its a shame I can't imagine anyway to tie in a portion of the rate sweep (say 1/20) into the depth sweep - an easy trick is that the ear incorrectly feels a proportion (decrese I think?) change in depth as speed increases (much like it falsely links true trem to volume level loss).
I've never noticed a change in depth as rate increases. I can see how some might notice that though.
I suppose I could try a reverse audio, so that way the speed increases faster through lower speeds and increases slower through faster speeds (If that makes any sense.)
Makes sense to me - worth playing with as well, I know that I don't use any effects treadle in an even manner so the taper would be a huge changer in my case, accellerating at a decreasing rate and slowing at in increasing rate actually mimics the physics of some spinner applications...
Well, the Dunlop RotoVibe uses a 50K pot, but I believe it's audio taper.
If only they made pots that would work with 180 degree spins, maybe expression pedals would be easier!