So I'm just starting to produce. So far I've only synced Behringer TD-3-MO with the Rhythm as a master and it worked fine. The tempo on the Rhythm itself is steady. I also djay, so I think, I would have noticed if there had been fluctuation. I've seen two guys complaining about the clock, but maybe it has been something to do with their setup. Maybe I'm anticipating for a problem that doesn't even exist.
Has anyone used RK-601? The description says that you can "add tempo related MIDI messages to the incoming signals or button"... to a simple sync pulse! Sounds great! How does that work? Like options 'toggle' or 'resync'...?