You'd usually want 3 phases for a brushless DC motor, right? Though I'm sure theres a cheap Chinese 3/4 channel DAC on LCSC since the output quality won't matte

You'd usually want 3 phases for a brushless DC motor, right? Though I'm sure theres a cheap Chinese 3/4 channel DAC on LCSC since the output quality won't matter. I haven't considered using a DAC with a motor before, but that strikes me as extremely inefficient, which is one of the design considerations. You're basically going from a simple class D amp to a class A one. The motor has plenty of inductance so you may as well PWM it for efficiency.