It has come to our attention that there are compatibility problems between some samplers (Ensoniq and Yamaha primarily) and some multi-port MIDI interfaces. This is due to the fact that these samplers transmit their MIDI data in very large MIDI packages, something that not all multi-port interfaces can handle. If you run into this problem, either switch to a simpler MIDI interface for communication with this sampler, or contact the manufacturer of the MIDI interface to see if there's another solution.