if you are using the regular midi ports, please be aware that a full event takes about a millisec to send.. a 9-note chord on 9 channels will therefore take at least 9 millisec to be transmitted.. human threshold for "instant" is about 6msec... human threshold for audible phasing is much lower than that.. combine this with sending CC's on those same channels, and the notes get spaced even further apart...
please note as well: 1msec per event implies maximum 1000 events per second per midicable... sending more than that will go out of sync by default
