1.upgrade DAC chip, using PCM5122 chip of high end, using I2S interface, and can be through the I2C interface to adjust audio volume parameter adjustment; supports 16 to 32 bit audio data format; distortion and dynamic is very perfect , support the tall sampling rate of 384kHz, 112dB dynamic range, degree distortion -93Db.For with no sonic boom run 120dB squelch signal to noise ratio (SNR).soft upward or downward oblique wave and analog squelch. 2.PCM5122 also integrated negative charge pump, the output without DC blocking capacitor; 2.1Vrms ground center output; ability to suppress very good band noise. Through the load support low to 1K, PCM510xA can drive a plurality of parallel products. 3.output ports with gold plated RCV dual terminal and gold-plated 3.5mm Headset seat. 4.the isolated power supply design, make the for raspberry pie power supply and DAC part of the independent power supply isolation, and through the bead altogether without mutual interference, get rid of the current sound 5.welding free, direct plug expansion board can use, and the use of I2S interface direct decoding digital to analog, non USB DAC interface 6.increase for double color LED provides state display, red for DAC power indicator (power normal bright), the green light for the working condition of DAC lamp (decoding and bright, stop or does not work out), better understanding of DAC work 7.perfect compatibility for raspberry pie official PI HAT size, gold plating process of tall based on PCB board, arc wire (high-end HIFI DAC adopts arc wire), better guarantee the impedance of the signal continuity, reduce the signal reflection and refraction. 8.Provided with an infrared receiver interface Volumio software parameters: Ready to play: flash it and you're ready Audiophile Quality: bit perfect playback FLAC, WAV, MP3, AAC, ALAC, PLS support Music libraries on Samba, NFS and USB drives Webradios support out of the box<