>One important subtlety is that after the DAC (which is just sample-and-hold) there's a Sallen-Key low-pass filter tuned at about 16kHZ, You mean IC54 and IC56

>One important subtlety is that after the DAC (which is just sample-and-hold) there's a Sallen-Key low-pass filter tuned at about 16kHZ, You mean IC54 and IC56? I noticed them on the circuit but didn't know it was tuned SO LOW! Wasn't the sample rate over 50KHz for each voice? 16Khz looks overkill for such sample rate. I know this is a time-division-multiplexed DAC so pehaps the time division multiplexing generates even more artifacts of their own? I would love to see a circuit that replaces the whole DAC section with 16 separate DACs that then mix their sound on the analog domain...