First, make sure you have the most up to date OS on each unit:
Then do a program dump from one unit to the others, making sure you have the same programs on all units you want to Polychain. You can use the programs from any Evolver.
The process for the setup is as follows:
1) Connect a midi cable from the Mono Evolver Keyboard Polychain Out to Evolver Desktop #1 Midi In.
2) Connect a midi cable from the Evolver Desktop #1 MIDI out to Evolver Desktop #2 MIDI in
3) On Mono Evolver Keyboard Global Menu set: Midi Channel to: ALL, and Polychain to :3
4) On Mono Evolver Keyboard Set Midi Clock to Midi Out.
5) On Desktop Evolver #1 set Midi Clock to IN/OUT.
6) On Desktop Evolver #2 set MIDI clock to IN.
This should be all you need to get the Mono Evolver Keyboard and two desktop Evolver units to play in a Poly Chained setup. The procedure is the same for additional units, just change the Polychain setting in the Mono Evolver Keyboard's Global menu to reflect the total number of voices you have.