An AS3394 Voice Card controlled by RP2040.
Schematics and Routing in KiCad. Uses 30Khz PWM with 12-bit duty cycle and 1KHz Low Pass filtering to produce control voltages.
Mainly a way for me to learn and experiment with discrete Sallen-Key and MFB filters. Also a way to avoid out-of-stock DACs during the chip shortage.
Work-In-Progress photo of board:
