Below are links to overview pages for board designs currently available. Each page gives a small summary and overview of the board, along with power supply and suggestions for other hardware requirements. Each page has a link to the GitHub repository for the board.
uCODEC A miniature CODEC board (5cm x 5cm) with 4 analogue differential inputs and 8 analogue differential outputs. Design files on GitHub,
ADAU1966 with Passive Filters (16 Differential Outputs) This board features the ADAU1966 16 channel DAC chip. This uses 4xTDM4 or 2xTDM8 or 1xTDM16 digital inputs (I2S connector) to give 16 differential audio outputs. This has only passive filters on the DAC output but is capable of driving external PCBs without issue.