Audinst HUD-mx2 The Finest Quality DAC with Pow- erful Dual Headphone Amplifier Can be connected to an iPad (with a camera connection kit) or a smartphone (with an OTG cable) that supports the USB audio Adopts a high purity TCXO for the clock generator in the USB controller Adopts a high-performance ALPS potentiometer and the highest grade aluminum knob for the front panel volume controller Adopts a high level film capacitor from WIMA in the low-pass filter area Adopts total eight dedicated regulators and a number of high-performance low-ESRs and tantalum capacitors in main parts for stable and high-quality power supply. Adopts high-performance solid capacitors having super low-ESR & high ripple current in the DACs power side .Adopts highest grade metal film registers from Vishay-Dale normally used for high-end audio equipments .Quipped with the DDC function that converts USB digital audio signals to S/PDIF (optical TX) output .Supports 88.2kHz signals that most USB audio DACs do not support.Embedded with an anti-pop circuit to eliminate unnecessary noise when the power is turned on or off