[sdiy] vactrol panning (across 4 outputs?)

[alfred.pear at gmail.com]

hi synthesists -

i'm sure many of you are familiar with this very elegant two-channel
panning circuit, using two vactrols (based on a buchla design,
apparently):
http://www.simple-answer.com/vac-panner.jpg

i feel like there must be a way to nest and scale several transistors
in there to make this circuit response across four channels of
output....but i'm not a very skilled designer..

any suggestions?

sincerely,
a. p.