Add expression input to Stereo PolyChorus

[hangnef]

I've read through just about every post on this forum I could find about adding EXP input to pedals, lots of good info.

A lot of posts refer to this:

http://www.geofex.com/Article_Folders/xprnped.htm

The Stereo Polychorus' Rate control looks like it would fit the exception example (LED/LDR) of a pot that is a voltage divider but one of the terminals is not attached to ground.  However, there's no description on how to do it.

Here's a picture of the circuit as reversed for a DIY version of the pedal.



Has anyone done this type of mod successfully w/ the LED/LDR?  Could it be done w/ just the switched jack?  AnalogMAN does this mod, not sure how he does it.