While many-channel audio solutions have existed for Teensy for some time, they were mostly based on the Cirrus Logic CS42448 codec, which has sadly been discontinued.

Australian PJRC forum member palmerr has taken up the mantle of multi-channel support with a new board based on the TI TLV320AIC3104 stereo codec. With four multiplexed codecs, each board features four “wing” boards for connecting pairs of TRS, XLR, or combo XLR connectors. The board is stackable, for up to 16 inputs and 16 outputs. The design is very CPU-efficient, using just 0.12% on a Teensy 4.0 to drive 16 output channels from a single sine generator.

Finished boards are available on Tindie, with Gerbers and a board-specific library available on GitHub. An extensive thread detailing the project’s evolution can be found on the PJRC forums.