iBasso D14 Bushmaster Portable Headphone Amplifier/DAC with Optical & 3.5mm Stereo to RCA Connection Kit Includes iBasso D14 Bushmaster Headphone Amp/DAC, Carrying Pouch, USB charge cable, 3.5mm to 3.5mm interconnect, OTG cable, silicone strap, 3.5mm Stereo to RCA connection cable, SPDIF-TOSlink Cable, Extreme Audio Travel Charger and Warranty Card(One Year USA Warranty) Warranty from Authorized iBasso Dealer) Please download manual from manufacturer website. Recommended Headphone Impedance 8-300Ohms, Works as a DAC+AMP Combo, a standalone AMP, or a standalone DAC (Line out function) XMOS USB audio controller, takes up to 32bit/384kHz PCM signal, and up to 256x native DSD signal from Windows PC and Mac computers OPAMP+BUF design, ensures high current and high power output Flexible inputs, takes Windows PC and MAC computers USB digital signal (USB Soundcard), OTG audio signal from Android 4.1 or above device, digital signal from iPhone/iPad with camera kit cable, takes coaxial input and optical input