Each of these switches represent the 5 audio loops available on the ML5. When a switch is lit, the loop is engaged and part of your signal chain. When a switch is not lit, the loop is bypassed and not in the signal chain.
Press this button to put the ML5 in learn mode. When the Learn button is blinking, the ML5 is in learn mode.
This is where MIDI messages flow out/thru from the ML5. This allows you to chain the ML5 with other devices. The ML5 does not generate any MIDI messages itself.
This is where the ML5 receives MIDI messages.
This is where the audio chain begins and ends.
Audio signal flows out from the sends. Connect the sends to the inputs of your effect pedals.
Audio signal flows in from the returns. Connect the outputs of your effects pedals to the returns.
Connect a 9VDC center negative power supply here.