The USB port on the back of AUDYA can be used for ...

A. Data transfer between AUDYA's Hard Drive and your computer (in which case MENU - MIDI - UTILITY - USB MIDI = "--")

OR

B. MIDI communication with external USB Midi divices (in which case USB MIDI = "ON".) [which is the answer to your case above]

The ON/OFF is set by pressing F6 to toggle between both values.

Hope this helps.

Thanks,

AJ