Details: AD 18 is a small full digital class d bluetooth amplifier built-in headphone amplifier supports subwoofer output.Connect it to your computer and use it to drive your headphones with an amplifier or to power your passive speakers(4ohm speaker produces 80Wx2 output power).Sophisticated matting aluminum housing reduces interference. Patented SDB sound and +-8 level treble and bass adjustment. Independent headphone amplifier design and advanced DSP technology makes the unit more desirable. Amplifier Chip: Using TAS5508C for digital signal DSP processing and Pre-Amp.TAS5342A for digital signal rear-AMP. It will be through LC filter and then send to amplifier output jack. Digital Receiving Chip:CS8422.It receive optical and coaxial signal and all signal transfer. USB chip:TAS1020B. Supports stereo sound 24bit 96kHz.For much better sound, we use SDPI output instead of internal DAC output design. Strong anti-interference ability and More High-Fidelity. HP Amplifier Chip:MAX97220A. Dual-OP amplifier:NE5532 with High efficiency low noise. Analog Digital converter IC :CS5341,Accurate to 24 bit 48kHz.Convert AUX signal to digital signal. Then digital signal processing by CS8422 Specification Type: Full digital decoding amplifier Input port: USB AUX 3.5mm Coaxial and Optical 1 Bluetooth Optical 2 Output Port: Amplifier output port 3.5mm Headphone port Subwoofer Voltage: 24V Output power:80W x 2 SNR(Signal to Noise): 90dB THD+N: 0.04% Power consumption: 50W Standby power:0.8w EQ adjustment: 7 Headphone output(32ohm): 53mW@THD=0.04% USB sampling rate: 24bit 96kHz Optical sampling rate:44.1kHz-192kHz Coaxial sampling rate:44.1kHz-192kHz Treble adjustment range: ±8db,Bass adjustment range:±8db Net Weight: 572g Gross Weight:1585g Machine Size: 172*51*85mm