Saturn:Digital Audio (SPDIF) Mod

There are two boards that will allow you to obtain digital audio: Will's Sega Saturn SPDIF Kit and the Pep Audio board by citrus3000psi. There are some reports of issues with the Pep Audio board, so you may want to opt for Will's kit.

Will's Sega Saturn SPDIF Kit

Required Parts

• Will's Sega Saturn SPDIF Kit
• (Optional) TOSLINK battery door

Installation

The Sega Saturn has 3 types of DAC Chips depending on the motherboard version number, locate the DAC chip on your motherboard to find which one you have.

Signal	TDA1386T	PCM1710	PCM1717E	YMF292 (SCSP)
EMPH: Emphasis	13	27 - C62	C62 (North Pad)
RST: Reset	15	25	Pin 18 on chip
ILRCK: Word Clock	5	Pin 1 (TP112)	Pin 4 (TP112)	63
ISCLK: Bit Clock	4	Pin 3 (TP111)	Pin 6 (TP111)	62
SDIN: Audio Data	6	Pin 2 (TP110)	Pin 5 (TP110)	61
OMCK: Master Clock	12	Pin 5 (TP113)	Pin 1 (TP113)	64

1. Connect wires from the mod kit board solder points (under the blue line) to the following points to the Sega Saturn DAC chip using the table below to find the corresponding leg number on the DAC chip.

   

2. If your Saturn has the TDA1386 DAC, bridge jumper J1. If your Saturn has the PCM1710 or PCM1717E DAC, bridge jumper J2.

   

3. Connect the following 3 points to the SPDIF connector and find a suitable mounting location for the connector.

   

Pep Audio Board (SPDIF or TOSLINK)

Original guide adapted from a post by citrus3000psi. A good writeup about this mod can be found on FireBrandX's site.

This tutorial assumes you have a TDA1386T DAC chip in your Saturn.

Required Parts

Parts are dependent on if you want SPDIF or TOSLINK:

• Pep Audio 1.2 PCB by citrus3000psi
• TC7W04FK chip
• TC9231N chip
• Two 0.1uF capacitors (0603 size)
• If using TOSLINK:
  • TX178A (TOSLINK port)
  • SPDIF Narrow PCB by citrus3000psi OR TOSLINK battery door
• If not using TOSLINK, 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 "SAT" pad on the Pep Audio PCB to the pad next to it.
4. On the back of the motherboard, solder these four points to the Pep Audio board.
   1. DATA on motherboard to DAT on Pep Audio PCB (not DATA!).
   2. BCK on motherboard to BC on Pep Audio PCB.
   3. LRCK on motherboard to LRC on Pep Audio PCB.
   4. MCLK on motherboard to MC on Pep Audio PCB.

   

5. Solder +5V to pin 7 of the TC9231N.

   

6. 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 port.
   • If using a SPDIF port, connect DATA on the Pep Audio PCB to the data pin and GND to GND.
7. Mount your SPDIF or TOSLINK PCB. This is one suggested location, but it may depend on what devices you may have installed in your unit.

   

8. Mount your external jack. This is one suggested location, but may require trimming of the case.

   

• Example completed install: