Vortex Sound Research

I have a volca beats and bass, bought used with no manuals. I would like to know how to synch these two so that they may work together, output to a small amp/speaker. I have searched for info but all I can find is videos of others making these synths be in sync but no on explains how they do it. I have tried tried various setups but nothing seems to work. Will someone help me out? Thanks.