PCM5122 DAC chip and I2S interface, Perfectly compatible with the PI HAT size, PCB board with gold plating on the tall, curved traces (high-end HIFI DAC are using curved alignment), to better the continuity of the impedance signal to reduce signal reflections and refractions It has I2S port and you can use the I2C port to control the volume and the frequency parameter. It support 16 to 32 frequency data . Distortion and dynamic condition are ideal. It supports the high 384 kHz sampling frequency and dynamic range is 112dB with distortion factor -93Db With isolated power design, the power and DAC part of the power supply are isolated. Common ground without disturbing each other through the beads, it can the current sound. material: metal Package Contents: 2 x Sound Card Module Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm. After using this expansion board, can coordinate with the broadcast system (volumio,system etc.) to set up your own HIFI player network PiFi Digi / DAC+ / HIFI Digital Audio Card Pinboard For 3 2 Model B B+ Updated DAC chip with BBTI Company's PCM5122 chip.