SMAKN&reg; DC XR1075 BBE Circuit Board Tone Adjustment Volume Control Upgrade Module model: XR1075 Power Supply: AC 6-12V DC 9-24V Audio input:(RCA socket): CDs, computers, mobile phones, MP3, MP4 Audio output: Connected to the amplifier (2-channel) Potentiometer(left to right): Bass adjustment; Treble adjustment; Volume Adjustment