AUDIO IN/OUT: Legend can be connected to either a keyboard amplifier via outputs left / right. Possibly, via 11 pin connection, it can be connected to a Rotary Speacker.
AUDIO PEDALS OUTPUT: Legend is the only one with a pedals output dedicated to the sound of the pedalboard, without getting into the channel of Vibrato/Chorus and Rotary Emulation.
FX SEND/ RETURN: Be able to connect your favourite external effect.
ANALOG IN: It allows you to use the effects of an external instrument.
INPUT GAIN: It allows you to control the volume of an external instruments.
EXP: Expression pedal
ROTARY: To change the speed of the Rotary.
HOLD: Hold control both for Legend and for an external instrument.
FULL MIDI: Out 1, Out 2, In, Thru, Pedalboard In.
USB TO HOST: useful to connect a computer for MIDI and software update.
USB POWER CHARGE: You can power supply Smartphone / Tablet.