Vinyl adc osc

Discrete 3rd-order delta-sigma audio ADC: stacked KiCad PCBs, SPICE simulations, 3D-printable enclosure, and laser-cut acrylic top

A coaster-sized single-sided board that fills the X1 DIP-8 socket on the already-built digital board, standing in for the unobtainable oscillator can. Electrically it is the can: a Pierce oscillator (74HCU04 + the found 2-pin 6.144 MHz crystal) whose buffered output leaves on the socket's OUT pin. The same blkpierce block draws this module, the rev B digital board and the simipierce testbench, so the three cannot drift apart. Design rationale, and the two values that are load-bearing (Rs = 2k2, and unbuffered 74HCU04): docs/design-notes.md §5.