Creative Soundblaster to Soyo SPDIF breakout board hack
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Hello, this page is a quick and dirty description of a simple hack I pulled off. I own a Soyo Dragon Plus motherboard, which contains a Cmedia sound chipset. The chipset seems pretty horrible, the outputs appear to be above the standard line level causing distortion on my mixer when the volume is at 100%. The drivers caused instability in some applications, but unfortunately were not the only issue. I finally got off my ass and decided to turn off the internal sound card and put in a Sound Blaster Live! CT4670 I had laying on the table. I upgraded to the Soyo board to replace an Asus A7V board with a Turtle Beach Montego II which lost Windows 2000/XP support when Creative owned Aureal. I had hoped to solve issues with IRQs and slots, I was trying to run high end video editing hardware on a fairly loaded system. The Soyo brought the sound, promise raid and network on board freeing up slots for the digisuite and cooling hardware. Didn't work out quite so well, but hey everything is working now.

But the sound card, had to get rid of the on board sound. Sound blaster it was, but from time to time I like to dump things off using SPDIF and TOSLINK.

The Soyo comes with a little board called a SY-AUDIO01. Basically it takes 5 volts to power the TOSLink emitter and maybe a chip, as well as SPDIF in and out plus some extra audio channels from the Soyo board and provides the connections.

The Sound Blaster Live! Value CT4670 sounds good and is stable. Good drivers, midi support, and the option of SPDIF.

The Creative card has a header for an optional breakout of some sort. They try to sell the live drive, which mounts in a drive bay. No good for me, my box is rackmount and the drive bays are covered by a door. The SY-AUDIO01 is all I needed.

The Soyo motherboard manual is most excellent and provides the pinouts of the motherboard's audio breakout header. Somewhere else online I found the pinout of the Soundblaster Live! SPDIF connector. The rest was left to 15 minutes and a screwdriver.

I used the ribbon connectors from an old AT style bracket that had a game port and a serial port. I used the 10 pin header for the serial port for the Audio01 side, and the Game port header (16 pin) for the creative side. There are 4 connections that need to be made, +5 volts, Ground, SPDIF in and SPDIF out.

Remember to pay close attention to the header and which pin is which. I put the dissasembled header connector on the pins and tested the pins with a resistance check on a meter before finalizing the connections and powering on the system.

Sound Blaster SPDIF (LIVE! VALUE) pinout
2 = GND
3 = KEY (No pin)
4 = VCC (5 volts)
5 = GND
9 = Out 1
10 = GND
11 = OUT 2
12 = OUT 3

3 = 5 volts in
4 = Key (No pin)
5 = Center channel line out
6 = Subwoofer channel line out
7 = GND
8 = GND 9 = Rear Right
10 = Rear Left

Okay, So here it goes:
Sound blaster side to SOYO Side
Pin 1 to Pin 1
Pin 2 to Pin 7
Pin 4 to Pin 3
Pin 6 to Pin 2

I ignored all the other stuff. To me, I could care less about surround sound on my PeeCee. If I want it, an ac3 decoder on a 6 channel SPDIF/TOSLINK seems like the way to go. Silicon Graphics has it right, since like 1993 they ship their computers with 48khz capable sound hardware that does line in, mic in, headphone out, line out, and digital in and out. Nothing else is needed, it is high quality and sounds good. Well, somewhere along the line they made it so you can switch the mic in to line in 3+4 and headphone out to line out 3+4, which is bad ass. Then somewhere they added AES/BEU and lightpipe interfaces. More bad ass. But still, there is no excuse for PC hardware to have such a wide range of sound cards that all support basically the exact same feature set with some gimmicks thrown on top.

A few pictures:

SB on the right is connected to a SOYO breakout on the left.

Close up of a game port ribbon header used on a serial port ribbon cable (cut off the DB-25/DB-9/DB-15 on one cable, then take the connector on the other cable off).

Minidisc deck, din-unlocked and receiving digital audio from the Soyo breakout from a soundblaster live! value.

Didn't try recording on the computer. So who knows if that works.

Also, you have to install the Soundblaster drivers from Creative before the SPDIF output goes live on the SB cards. Win2k internal drivers didn't seem to cut it. Updated Jan. 31st, 2004