Headphone Amp - DAC, OLED display, hybrid power system with 220mAh battery, rotary dial for volume control, two ESS ES9038Q2M chips, two Ricore RT6863 headphone amplifiers, Hi-Res support up to 768 kHz/32 bit and DSD512, FPGA system for excellent signal processing, 4.4mm balanced connector, 3.5mm connector, USB power supply, compatible with Android OS, iOS, Windows and macOS, black