This video shows step by step how to set up a Little Phatty to be polyphonic with a stack of Slim Phatty's adding extra voices.
Watch the Polyphonic Slim Phatty Chain in action: vimeo.com/20920400
1. Set the LP Output MIDI channel to channel 1
2. Set each Slim's Input MIDI channel to channel 1 (not required to be channel 1, but needs to be SAME channel)
3. Plug MIDI Out of the LP to MIDI In of the first Slim
4. Plug the first Slim's MIDI Thru to the second Slim's MIDI in, and so on.
5. All audio outs need to be plugged into their own channel on a mixer or audio interface
6. In the LP's Master menu, scroll until you find MIDI setup
7. Scroll within MIDI setup until you find Poly
8. Set the Little Phatty to be 1 of X, the first Slim to be 2 of X, the second to be 3 of X and so on, where X is the number of voices you have.