This is a dedicated HIFI Digi+ expansion board (PiFi Digi+) designed for Raspberry Pi 2 B, B+/A+. It uses Wolfson's high-end digital chip (WM8804G). It uses I2S interface, non-USB interface. Use this extension. After the board, users can build their own network HIFI player with audio playback system (such as: for volumio, for xbmc system, etc.) The expansion board provides two output interfaces: fiber optic (S/PDIF) and coaxial (RCA) for external amplifiers. device. With it, it can solve the problem of large power consumption of the PC, slow startup and shutdown, high power noise and so on. Features: 1. The digital chip uses high-end WM8804G chip for Wolfson's. It uses I2S interface. 2. The output port is output by optical fiber and coaxial interface, which is convenient for users to connect external power amplifier. 3. Support hardware mode to control the volume (I2C interface). 4. The power supply adopts power supply for Raspberry Pi, no external power supply is needed; and the Pi-type filter power supply design is adopted to effectively reduce the interference of the power supply. 5. Direct digital output using I2S interface, high degree of reduction, non-USB interface DAC mode, does not occupy other extended GPIO of Raspberry Pi. 6. Provide power indicator for easy viewing of the expansion board status. 7. The PCB board adopts the gold plating process on the tall, and the curved traces (the high-end HIFI DACs adopt the curved traces) to better ensure the impedance continuity of the signal and reduce the signal reflection and refraction. 8. The optical fiber interface adopts imported HIFI-class high-quality fiber optic seat. The coaxial interface adopts Pluse's imported audio isolation transformer to provide good digital audio while protecting your audio equipment and board.Foreign similar products have been removed for the cost, for the voice of reliability we will not begrudge the cost. 9. Integrated infrared receiving function, it is more convenient to control playback when there is no network. 10. Support 16 to 24 bit audio data format. Distortion and dynamic are very ideal. 11. Supports high sampling rate of 192kHz. Advanced debounce technology can control Intrinsic period jitter within 50ps RMS with high degree of reduction. Specifications: FLAC, WAV, MP3, AAC, ALAC, PLS: support Music libraries on for Samba, for NFS and USB drives Webradios support out of the box Control it via integrated Webui with PC, Smartphone, Tablet Airplay capability Ramplay: Support for DSD Native Playback Multiroom Playback via App for Android Output playback device Selection Audio out I2S (from for Raspberry pi's P5) Wireless Network configuration Various resampling options: up to 24bit/192kHz Size: Approx. 6.5*6.5*2cm/2.56*2.56*0.79inch Package List: 1 * Expansion Board 1 * Screw Bag 1、The digital chip uses high-end WM8804G chip for Wolfson's. It uses I2S interface. 2、The output port is output by optical fiber and coaxial interface, which is convenient for users to connect external power amplifier. 3、Support hardware mode to control the volume (I2C interface). 4、The power supply adopts power supply for Raspberry Pi, no external power supply is needed; and the Pi-type filter power supply design is adopted to effectively reduce the interference of the power supply. 5、Direct digital output using I2S interface, high degree of reduction, non-USB interface DAC mode, does not occupy other extended GPIO of Raspberry Pi.