Saturn:Digital Audio (SPDIF) Mod

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:

• SPDIF:
  • Pep Audio 1.2 PCB by citrus3000psi
  • SPDIF Narrow PCB by citrus3000psi
  • TX178A (SPDIF port)
  • TC7W04FK chip
  • TC9231N chip
  • Two 0.1uF capacitors (0603 size)

• TOSLINK:
  • PEP Audio 1.2 PCB by citrus3000psi
  • TC7W04FK chip
  • TC9231N chip
  • Two 0.1uF capacitor (0603 size)
  • (Optional) TOSLINK battery door

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: