Dual Wolfson WM8740 DAC Chip + TI PCM2706. USB signal input, provides I2S interface for decoding. Works as a DAC+AMP Combo, a standalone AMP, or a standalone DAC (Line out function). 2-Setting Gain Switch for impedance matching. OPAMP rollable. AMP section can be powered by either USB or 9V battery. Measures 55*21*92mm, and weighs 130g.- 9hours play time with 9V 300mAh battery (when powered by battery). Comes with extra enclosure (black color), leather pouch, USB cable, warranty card, and owner’s manual.