Dual WM8740s High Performance D/A chip. TI TAS1020B USB receiver chip, handles up to 24Bit/96KHz USB digital signal. OP+BUF structure for amplification. 2-Setting Gain Switch for impedance matching (+3/10dB). Works as a combo or a stand-alone AMP, DAC, USB soundcard. Powered by 12.6V Li-polymer rechargeable battery pack, or USB power. 20 hours play time with stock OPAMPs. High output power, 650mW+650mW into 32Ω. Measures 55*24*92mm, weights 150g.