The OC-3 GUITAR IN input and BASS IN input can not be used simultaneously together.
GUITAR IN will always take priority of the two inputs.
BASS IN is optimized for bass instrumentation input for lower frequency tracking.
Equipped with octave effects especially suited for basses.
Plug into the BASS IN and disconnect any connections to the GUITAR IN jack and the OC-3 internal processing switches to the optimal conditions for use with bass.
Connect using standard 1/4" TS mono guitar/bass instrument cables like our BIC/BOSS Instrument Cables:
https://www.boss.info/global/search/?q=BIC