Features Dual Wolfson WM8740 DAC Chip TI PCM2706 for 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 OPAMP rollable AMP section can be powered by either USB or 9V battery Comes with 3.5 to 3.5 interconnect cable, pouch, USB cable, and OTG cable Specifications Frequency Response 4Hz - 20 KHz - 0.5dB (DAC)17Hz-100KHz-0.5dB(AMP) Signal to Noise Ratio 99dB (DAC), 104dB (Amp) Crosstalk 97dB (DAC), 101dB (AMP) Total Harmonic Distortion 0.005% @ 1kHz/0dB (DAC) 0.005% @ 1kHz/0dB (AMP) Output Power Up to 230mW+230mW into 32 Ohms Line Output 1.5V rms Gain +3dB/ +10dB (AMP) Battery Life 9 hour (with 300mAh battery) Recommended Headphone Impedance 8-300 Ohms Case Dimension 2.36W x 3.62L x 0.79H (inch) Weight 102g or 3.9oz (without battery)