I need the Pitchfactor's tempo synced with my RC50s' tempo so that the harpeggiator will line up with the click track on my RC50. If the tempo jitters, then the arpeggiator sounds behind or ahead of the click track. I synced my RC50 with the MICROKORG synthesizer and it lines up perfectly on every downbeat and has no jitter . I also changed the MIDI cable to see if that was the problem. I have 3 RC50s and have never had a problem with any MIDI sync options. It might b possible that it is not compatible with Pitchfactor. I am going to sync the Pitchfactor with a master MIDI clock at the studio soon to see if that will work. The Filter option is ok but not perfect.