Mutron Phasor 2 - simple expression pedal sweep control

[skyled]

I want to be able to sweep the phase on the Mutron Phasor 2 like you can on the Biphase. I came up with this simple little circuit add-on which I adapted from the ROG Phozer who adapted it from RG Keen's Univibe mod:
http://www.runoffgroove.com/phozer.html

I've only simulated it so far but it seems to work great.
I drew up this modification to the PedalPCB Mutron clone schematic (because it's roomier), but Madbean's Glasshole will modify in the same way.
I did it based on using a 10kb linear expression pedal, with a resistor to taper the pedal into a fake log pot. The log pot seems to be better in this case.
I'm not sure if the diode to ground is actually necessary.

Essentially, the expression pedal just controls the brightness of the LED in the LED/LDR. The switch determines if the phaser sweeps using the LFO or the expression pedal.