I've been searching for the perfect synthesizer router for my Serge.
The Serge Bi-directional router is fine but I would love to have more ins/outs.
Recently I built a NLC 32:1and NLC Router for Eurorack.
All excellent and I might one day adapt one for the Serge.
One I haven't tried is the serge Quad switch which seems to be an adaptation of the earlier
Serge Triple Bi-directional R.
The module I'll build is the Cat Girl Synth CGS 88.
Ken's Build notes are here:
The Quad switch uses a CD 4013B.
Its a CMOS Dual D-type flip flop that works as a two bit binary counter.
It was mounted on a separate board off the original R4 PCB.
You can still find these.
D = Drain, S = Source.