iFi Nano iDSD DAC and Headphone Amp Combo Turn your iPhone, iPad, Android, or other smart device into a portable high-end audio source with easy plug-n-play Listen to any high resolution format natively and unaltered Reduces overall digital noise and jitter to the vanishing point to give you a more pure listening experience Features an SPDIF coaxial digital output for use with A/V receivers, 4K TV's, and Apple TV so you can enjoy high performance sound at home and on the go Built-in precision volume control will satisfy any audiophile