It's a pity about Teensy3 being effectively gone. I've got numerous eurorack modules based on the Teensy3 12-bit onboard analog output. The trick there is twof

It's a pity about Teensy3 being effectively gone. I've got numerous eurorack modules based on the Teensy3 12-bit onboard analog output. The trick there is twofold: one, if you're doing traditional digital audio, this output has a very 'old school sampler' sound that takes well to further processing. It's a really primitive output with a lot of character that sits well in a mix or performance: no trouble building an entire mix around sounds coming off this output. Two, because it's directly built into the Teensy and doesn't have as many intrinsic assumptions about what digital audio is, you can overclock it to sample rates as high as a megahertz or so, while still running the same audio library. That means if you're just putting out a square wave, the ONLY limitation on your quality is aliasing, as bit depth no longer matters. If you're doing multiple square waves you still don't need full use of the 12 bit analog output to do it. And if you're at 1mHz aliasing is next to nothing, so all of a sudden your cheesey 'bad' output is in fact shockingly good. Even waves which do require the 12 bit resolution are a lot better with no significant aliasing. I run four-note chords with two oscs per note, portamento, and additional waveforms, on a single Teensy, at upwards of 300kHz. From what I can see, no audio hat does this. They're all mediocre CD quality. I'm sure you could build a ladder DAC out of raw digital outputs on a more modern Teensy and do just as well, especially if you ran even lower bit than 12 bit. Teensy3 has that analog pin just right there, though. Lovely :)