Fostex HP-A4 24-Bit Digital to Analog Converter/Headphone Amplifier 24bit DAC headphone amplifier Offers up to DSD 5.6MHz and PCM 192 kHz for superior audio playback functionality Quick and easy hi-resolution playback in combination with Fostex Audio Player software Hi/Lo gain selection (10 dB) for wider range of headphones Asynchronous transfer mode