monopoly arpeggio trigger

i'm pretty sure your mono/poly, like all Korgs needs a trigger which goes from high to low (z-trigger)
Roland gear and most others put out an low to high trigger (s-trigger)

from hyperreal http://machines.hyperreal.org/features/before-midi.html

"As with gate, triggers come in v-trigger and s-trigger. Most equipment uses a v-trigger, but occasional triggers (the arpeggio input on the Korg Mono/Poly, and the trigger output on the Korg DDM-110, for example) are s-trigger. "

I've had best results using a sampled snare from my DAW. Make sure the level is high enough to trigger. I was having the same problem and then realized my signal was too low.

like dez says you can trigger the mono/poly without proper s-trigger, just using the right sound.
I've had better luck triggering a mono/poly arpeggio with a rimshot sound from an 808, rather than a trigger from the same (whch is pretty much like the trig signal on the 707 i think...?)
maybe you can trigger it tightly using one of the individual outputs of the 707 or 727?

yeh - mp4 arp trigger is tricky - i can get mine to trigger from the gate out on my 101, but not my 303 gate or 909 trigger.  I generally use a sample too.  awesome synth tho

CHD is offering now a MIDIINTERFACE for the MONO/POLY:

http://www.chd-el.cz/index.php?id=409

it

is this an easy install?  (my experience is limited.)

just picked up a mono/poly and am very impressed by the sound.  very dirty and raw...  so far, liking it better than the pro-one or sh-101.