To set up the GMX212 amplifier to work with the FCB1010 MIDI controller, follow these steps:
1) Connect from the MIDI IN connector of the amp to the MIDI OUT of the FCB1010.
2) Keep CHANNEL and IN/OUT keys simultaneously depressed for 2 seconds.
3) Use the PRESET control to select a MIDI channel (1 through 16, "ON" = Omni mode, "OF" = off). When the display no longer blinks the selected MIDI channel is activated.