Use the following steps to mute the bass part in the DR-670:
1. Hold SHIFT and press the KICK (13) pad [UTILITY].
2. Release SHIFT and KICK, and then turn the VALUE dial to select "DRUM."
3. Hold SHIFT and press the TOM 1 (5) pad [PATTERN PLAY] to return to pattern play mode.
Note: This setting must be done each time the DR-670 is powered on, since it is not stored permanently into the memory.
1. Hold SHIFT and press the KICK (13) pad [UTILITY].
2. Release SHIFT and KICK, and then turn the VALUE dial to select "DRUM."
3. Hold SHIFT and press the TOM 1 (5) pad [PATTERN PLAY] to return to pattern play mode.
Note: This setting must be done each time the DR-670 is powered on, since it is not stored permanently into the memory.