DFR0803 HIFI Digital Bluetooth® Amplifier DFRobot DFR0803 HIFI Digital Bluetooth® Amplifier module comes with an AM interference suppression and filtering function. The Total Harmonic Distortion (THD) of the module is as low as 0.1% even when working for a long time at large power output. This DFR0803 module features 50W output power, volume adjustment knob, AUX+Bluetooth 5.0 input, dual-channel output, and 5V to 27V DC operating voltage. The DFR0803 Bluetooth power amplifier board works with 4Ω to 8Ω and 30W to 200W passive speakers. The higher the power supply voltage, the larger the output power.