High quality, portable headphone amplifier with built-in 24/96 USB DAC, providing high-resolution "go anywhere" listening from iPhone, Android and PC/Mac Digital input from iPhone or Android devices Custom iOS application TEAC HR Audio Player for iOS (free to download) offers 24-bit/96kHz high-resolution audio playback (No Apple Camera Connection Kit needed) High 160mW + 160mW output gain (at 32Ω load) Low 0.001% distortion (at 100mW + 100 mW output) Built-in BurrBrown PCM5102 high-performance D/A converter Discrete output amp section based on a push-pull circuit High quality OP1652 operational amplifier HIGH/LOW gain selector USB input from PC (24-bit/96kHz maximum) Works in conjunction with the TEAC HR Audio Player app for PC/Mac (free to download) to deliver high-resolution audio playback Combination optical digital/AUDIO IN input 3.5mm stereo mini headphone output Slim 21.7mm thick design; sturdy full aluminum body Internal rechargeable 2100mAh Li-ion battery with continuous battery life of approximately 8 hours USB-rechargeable Supplied with rubber fixing straps for securing HA-50 to iPhone or Android handsets Auto power save function