Adopts TDA7498E dual-BTL power amplifier chip, high power, good sound quality, no distortion, give you a great hearing enjoyment. Support Bluetooth mode (short J1, J2, J3, J4 located on the back of amplifier board). Four fixed gain settings available: 29.6 dB, 33.1 dB, 35.6 dB and 35.6dB. With stan..