Stronger output power and a line output added: use TI's classic power amp IC 3255, each channel can output 300W(4Ω) and easily to drive all 4-8Ω passive speakers; stereo RCA output is added, easy to connect another amplifier or active speaker / subwoofer to build multiple channel system and enjoy wonderful home theater experience. Separate control for left and right channels: two balanced and volume knobs are designed for adjusting the left and right channel output indepedently, compensate for the left and right channel of all outputs and prevent the sound field positioning from deviating from the center position. Also with sensitivity knob of VU meter, easy to adjust and match better with different input signals.
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