Bluetooth Power Amplifier Introduction 1:The product uses the latest Bluetooth BT4.0 module (CSR-BC7), effective reception distance of approximately 15 meters to 20 meters. 2:A2DP Multipoint Support 3:Standard:BT4.0,BLE,Class 1.5 Frequency Band:2.402G ~ 2.480G 4:Maximum Data Rate:3Mbps 5:For a variety of Bluetooth devices to receive. 6:Power amplifier modules ,use BTL class-D audio amplifier, Low power consumption, no heat sink? 20 W or40w or 100w continuous output power: RL = 8 O, THD = 10% at VCC = 16 V Wide-range single-supply operation (9 V - 16 V) High efficiency (? = 90%) Four selectable, fixed gain settings of nominally 20 dB, 26 dB, 30 dB and 32 dB Differential inputs minimize common-mode noise No ?pop? at turn-on/off Standby and mute features Short-circuit protection Thermal overload protection Key Functions:1:Play / Pause,Long press the button for 5 seconds Bluetooth is opened,Red green indicator lamp flashing alternately, search for Bluetooth devices (CSR-BC7), only the green light flashes, Bluetooth pairing success.? 2:The next choice key,Long press the button = increase volume, 3:The previous choice key, long press the button = volume reduction.? 4:Bluetooth the red and green indicator lamp flashing alternately? 5:Volume control potentiometer and power switch. 6:Two speakers connected,20W8ohm or 40W or 100w 7:DC input voltage:DC9-16V