[sdiy] gr-300 pitch tracker schematics?

[med]

Hey everyone, I was looking through the archives and saw mentioned the
GR-300 guitar synth and how someone was altering it to give v/oct
outs... I'd like to know if anyone has schematics for the pitch
tracking system. Would there be six (one for each individual out of
the hexaphonic pickup)? Or is it some clever multiplexing system? Does
it require any hard-to-get or highly-digital parts?

-MED, who's trying to avoid learning to build a six-note
velocity-sensitive polyphonic keyboard with some *very* strict voice
assignment rules