DROK&reg; DC XR1075 BBE Circuit Board Tone Adjustment Volume Control Power Amplifier Upgrade DIY 2 channel Compatible for AC/DC power supply, wide power supply without heating(AC9-20V; DC10-26V). No distinction between positive and negative of power supply, simple wiring. The audio channel uses the Nikon music series MUSE non - pole audio frequency special coupling capacitor, provide high sound quality. 6 original imported capacitor array parallel filter, provide stable power supply. Ultra small size(595720mm) , light weight, easy and convenient to install.