This mini Bluetooth Amplifier can be connected to your mobile phone, Raspberry Pi, and other main-boards with Bluetooth to DIY your unique speaker! With standard audio quality, the cost-effective amplifier offers 50W output power, volume adjustable knob, Bluetooth 5.0 input, and dual-channel output. It can be powered at DC 5~24V, and compatible with 4-8Ω, 30W-200W passive speakers.The Bluetooth Amplifier comes with bottom/top protective covers and supports overheat and short-circuit protection.Operation InstructionConnect the board with a speaker, power it on. Rotate the volume knob then the indicator LED lights up. Turn on the Bluetooth of your phone or Raspberry Pi, the “BT-WUZHI” will be searched, and then click to connect it. It connects successfully with a ding-dong tone, and now it can play music. The Bluetooth will be connected automatically when the module is powered on next time.NoteThe board will output adequate power only when the audio input and power source voltage/current are sufficient. The higher the power supply voltage, the larger the output power. Besides that, speaker impedance also changes the amplifier board power output. Please note that in the case of enough voltage and current, the larger the speaker impedance in ohms, the smaller the output power.Specification: Power Supply: 5-24V Input: Bluetooth 5.0 Audio Quality: standard Output Power: 50W*2 Compatible Speakers: 30W-200W, 4Ω-8Ω Channel: left/right (stereo) Bluetooth Transmission Distance: 15m(Without any obstacle) Protection: overheat, short-circuit Power Voltage: 12V--8Ω Speaker/12W(left)+12W(right), 4Ω Speaker/20W+20W 15V----8Ω/18W+18W4Ω/>30W+30W 19V----8Ω/32W+32W4Ω/>45W+45W 24V----8Ω/38W+38W4Ω/>50W+50WProduct Includes:Mini Digital Bluetooth Amplifier-50W*2 x1Acrylic Protective Case x2Screwdriver x120cm Power Wire x1Knob x1Accessories Package x1Heat Sink x1