Hi guys!
I made my Zynthian in a 19 "rack cabinet.
The idea is to use mainly with guitar, so I chose to use the audio injector.
I did some extra circuits too:
-
A simple preamp for each channel, with a peak indicator light
-
A controller made with arduino, with 12 potentiometers
-
For the encoders I made a simplified version of the plada with the MPC23017, the connection of the wires is done with soldering in the pins GPIO
I have not yet made the PCB for the MIDI connectors because I don’t need it now 
Here some pictures:
Front:
Back
Power Supply
PreAmps
Arduino Controller
MCP23017 Pcb
Regards, Rod