Arcam irDACII Audiophile Grade Digital to Analog Converter with Bluetooth DAC:ESS ES9016K2M Input: USB, SPDIF, optical, Bluetooth Frequency Response: 20Hz:20kHz, +/:0.1dB Total Harmonic Distortion + Noise: 0.0007% Signal-to-noise ratio (A:weighted): 117dB (24:bit)