Spent the day checking every circuit against datasheets to match the reference designs.

Found and fixed several minor issues—and even a few critical ones.

Review always pays off.

Also:

• Line / Phones Out changed to 6.35 mm jacks.
• MIDI IN / OUT upgraded to full-size DIN-5. I like small parts, but here I prefer the big ones.
• SPI chip-select pins were rearranged for a cleaner layout and domain separation.
• Added provisions for EMI filtering on all external connectors — not needed yet, but ready when it is.