Yamaha MU128 Owner's Manual page 99

Bank 001
For input of an electric or electric/acoustic guitar
(or other mic level instruments).
Bank 002
For input of a keyboard (or other line level instruments, such as
tone generators, rhythm machines, etc.).
Bank 003
For input of audio equipment (such as CD players, cassette decks, etc.).
Bank 018
For input of a stereo keyboard (or other stereo signals from line level
instruments, such as tone generators, rhythm machines, etc.).
MU128 Guided Tour
A/D Inputs
99