Denon DA10SPEM [Portable USB-DAC/headphone amplifier premium silver Hi-Res sound source correspondence] (Japan Import) Corresponding impedance: 8&#xFF5E;600&#x3A9; Reproduction frequency range: 2Hz&#xFF5E;100kHz Output terminal: Headphone /LINEx1 (3.5-mm stereo mini) Input terminal: USB-DAC(USB-MicroB) x1iPod/iPhone(USB-A) x1AUX(3.5-mm stereo mini) x1 Power supply: Built-in lithium-ion battery