I don't need recorded audio (SD card) or even fancy synths. My goal is just to have a reasonably clean output directly from the teensy to generate a tone (sine, square, sawtooth, or triangle) at line output level into an external mono amp driving a subwoofer for the purposes of a classroom experiment. The frequency will be variable between 30Hz-100Hz.

I don't think I need an additional DAC or the audio shield for this and I have 4 Teensy 3.1s sitting around from an abandoned project, so it seemed like AudioSynthWaveform and the DAC pin (A14) are what I wanted, but I can't find a basic hello world for sending such tones out to A14 on the Teensy.

My apologies is this is an overly basic question. I've been away from Teensy tinkering for a few years and this is my first step back in

ANY help (either a link to an example or a basic code snippet) would be greatly appreciated. Thanks!