Sound Card for the Raspberry Pi with inbuilt microphone Stereo RCA input and output, with volume knobs Headphone amplifier - 50 mW max power into 16 ohm and 30 mW max power into 32 Ohm headphones Standard GPIO available to allow you to keep stacking add ons and hats DAC and ADC : 96 kHz, 32 bit audio. Linux ALSA driver already integrated into the stock Raspbian release. Support and setup : http://forum.audioinjector.net