Although it is not possible to stop 1 unused channel, it can be used as a monaural amplifier by connecting each terminal of the unused channel as follows: Connect the power supply and GND in the same way as for the unused channel. Connect decoupling capacitors. Connect unused input pins to GND via coupling capacitors. Unused output pins can be left open, but we recommend connecting an LC filter for EMI protection. Connect a BSP capacitor.