I use the paia midi2cv8 converter with my monopoly.
I use the gate outs to trigger the arpegiator but I had to make a
special cable to convert gate to S-trigger format. This is very simple
to do:

http://www.doepfer.de/faq/gen_faq.htm#S-Trig

I like to use a CV+gate pair on the midi2cv and use the gate to
trigger the arp and the CV value to modulae the filter fm. The results
are excellent!