The USB input, coaxial, optical fiber and analog output.
3 push buttons, volume + - and mute control.
The main chip is used BB Company level HIFI PCM2704 USB decoding chip, its performance is superior to the most commonly used on the market of low-end microchip CM102S series, power is supplied by USB output can be connected directly to headphones.
Digital output to provide connection to a more advanced DAC decoder, SPDIF digital signal, in order to get the best sound quality. Because it's an external sound card signal-to-noise ratio and the sound quality is improved. PCM2704 is a monolithic analog-to-digital conversion chip. It has two analog conversion output channel and one integrated USB interface controller. The interface is in conformity with USB1.1 standards. PCM2704 can receive 44 KHZ and 48 KHZ, 32 KHZ sampling rate of 16 bit stereo or mono audio data, volume and mute function of chip internal integration, and can adjust the volume of the computer and synchronous mute.
Support 16bit 32KHz/44.1KHz/48KHz
Support 2-channel analog output,S/PDIF output Dynamic range/signal-to-noise ratio: 98DB THD+N=0.006%
Works with Raspberry Pi.
Something to help with Raspberry Pi applications https://code.google.com/p/squeezelite/