FW: [sdiy] Expression pedal

[jhaible at debitel.net]

> > Can anyone point me in the direction of a schematic for an expression
> pedal?
> 
> Tip is the voltage input, ring goes to +V, sleeve ground.
> So the tip is going to the wiper of the pot, sleeve
> to the positive side of the pot, ground to negative.

Right, this is one possibility.
Only that some pedals work the other way round, with tip
being the voltage supply (going to the cw end position)
and ring being the wiper (CV).
I *think* Yamaha instruments work like this, and who knows
which other manufacturers follow this "standard".

Most synths should have protection resistors, but then again
some older models might not. I think I have once killed
a pedal with a CS-50. The CS-50 is built to feed an incandescent
lamp inside a pedal, so with the wrong connection you have
considerable current flowing thru a tiny fraction of your
potentiometer as a worst case condition. Enought to create
smoke ...

JH.

-------------------------------------------------
debitel.net Webmail