3DO:Digital Audio (SPDIF) Mod

Original guide adapted from a post by citrus3000psi.

This guide is for a FZ-10 3DO with a AK4316 DAC. It may work on other models, so if you try it out, please update this page with the result.

Required Materials

• Pep Audio 1.2 PCB
• If using TOSLINK:
  • TX178A (TOSLINK port)
  • TOSLINK PCB by citrus3000psi.
• If not using a TOSLINK port, you will need your own jack.

Installation

1. There exists an issue (as noted by FireBrandX) with the Pep Audio PCB where some of the boards have extra ground fill in front of the pins and cause shorts. Use a multimeter to make sure none of the pads (GND excluded) have continuity to GND. If you do find continuity, you will need to use a hobby knife to cut off the area marked in red below:
   • 
2. Assemble the Pep Audio PCB.
3. Bridge the "PS1" pad on the Pep Audio PCB to the pad next to it (although it's for PS1, it's the same setting for 3DO).
4. On the top of the motherboard, solder wires from these legs on the DAC to the matching pads on the Pep Audio board.
   1. DATA on the chip to DAT on Pep Audio PCB (not DATA!).
   2. BCK on the chip to BC on Pep Audio PCB.
   3. LRCK on the chip to LRC on Pep Audio PCB.
   4. MCLK on the chip to MC on Pep Audio PCB.
   5. +5 on the chip to 5V on Pep Audio PCB.
   6. GND on the chip to GND on Pep Audio PCB.
5. Connect the output jack:
   • If using a TOSLINK port, connect +5V and GND to it. Also connect DATA (not DAT!) on the Pep Audio PCB to the In on the TOSLINK PCB.
   • If using your own SPDIF port, connect DATA on the Pep Audio PCB to the data pin and GND to GND.
6. Mount the Pep Audio PCB somewhere such as on top of another chip using double sided foam tape.
7. Mount your TOSLINK connector. One option is to remove the channel select switch and file the connector down and set it in its place. You will also have to cut the top metal shield a bit to fit it.