We all know how fun the Arpeggiator is on the Mono/Poly. I love mine. There is a problem, though, if you want to keep the arpeggiator in sync with MIDI devices, such as MIDI drum machines.
To solve this problem, I used an Arduino to make a MIDI-to-Trigger converter. If you're interested, you can check out the post below where I describe my converter and I show a demo video of me driving my Mono/Poly arpeggiator from MIDI.
http://synthhacker.blogspot.com/2014/02/arpeggiator-fun-my-midi-to-trigger.html
Fun!
Chip