Optical SPDIF out on a Soundblaster Audigy 2

Setting up an HTPC to run Media Center, I was looking to get an optical output so that I could hook it up directly to our receiver. Current sound cards with an optical out unfortunately run around $100 at the low end. I had a couple motherboards that actually have optical outputs, but for the life of me, I couldn’t get the one in the NF7-S to work in Vista, and while the Gigabyte 7VAXP-A’s worked with drivers from Realtek’s site, that motherboard didn’t like the mobile Athlon XP-M very much (it would only work if i set the onboard switches to a 100Mhz FSB which didn’t tickle me in a pleasant way). The 7VAXP-A wasn’t totally useless though… it provided me with one of those little cables that plugs into the motherboard and provides an output via a rear slot.

Problem of course was that the little accessory had 3 pins and plugged into the motherboard. The Audigy 2 I had kicking around (and wanted to use) had a digital out, but it was unfortunately a 3.5mm jack. I needed the TOSLINK style. It did have an SPDIF_IO section on the card, but it had a whopping 8 pins to contend with, as opposed to the 3 pins I had to work with. Pin-wise they didn’t look at all plug and play, but fortunately there’s a way to make it work.

A couple hours of searching led me to the following sites:
http://www.driverheaven.net/audio-general-technical-discussion/51279-creative-audigy-2-ad_ext-pin-assignment.html
http://forums.whirlpool.net.au/forum-replies-archive.cfm/506048.html

Basically, the first site listed has a great little pinout diagram of part of the audigy that someone posted, which looks like this (click on it for the full size image):
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That was great, but unfortunately, I didn’t have a clue what pins I needed to connect the 3 wires from my adapter, aside from obviously the SPDIF0 OUT. That’s where this exerpt from the 2nd site came in handy:

GND – ground, usually a black wire I think
SPD_OUT – a white wire usually
VCC – usually +5 Volts – usually a red wire.

I used a pin to get the wires out of the adapter plug that normally goes into¬†a motherboard, and started¬†connecting them to the Audigy 2 – the black to a ground, the white to the spdif0 out, and the red to the +5V. Low and behold, after grabbing drivers from Creative’s website, it worked!

Certainly, not everyone who comes across this post is hooking up the exact same accessory from the exact same motherboard to an Audigy 2 that I did. However, by looking at the Audigy’s pinout diagram, hopefully you’re able to adapt whatever you have to work.