Reduce switching noise of input gain control, mute, main volume, fader volume, bass, middle, treble, loudness, by using advanced switch circuit [Possible to control all steps] Built-in ground isolation amplifier inputs, ideal for external stereo input Built-in differential input selector that can make various combination of single-ended / differential input Built-in input gain controller reduce switching noise for volume of a portable audio input Decrease the number of external components by built-in 3-band equalizer filter, loudness filter, And, possible to control Q, Gv, fo of 3-band equalizer and fc of LPF,and fo, Gv of loudness by I²C BUS control freely It is possible for the bass, middle, treble to the gain adjustment quantity of ±20dB and 1 dB step gain adjustment It is equipped with output terminals of Subwoofer. Moreover, the stereo signal of the front and rear also can be output by the I²C BUS control Bi-CMOS process is suitable for the design of low current and low energy. And it provides more quality for small-scale regulator and heat in a set Package is SSOP-B28. Putting input-terminals together and output-terminals together can make PCB layout easier and can makes area of PCB smaller It is possible to control by 3.3V / 5V for I²C BUS