HTPC "Enhancement"


2007-12-22 5:49 am
HTPC "Enhancement"

For years, I've been searching on the Ideal STB solution to stream all of my digital content (audio and video) from my PC to my television. I've been using an I-O Data LinkPlayer2 for a couple years now, and have been very satisfied with the solution for the cost, but it has its limitations. The only real solution is an HTPC, but the cost and form factor has been a bit much...until recently.

Dell has a new product line, the Inspiron 531s. It's a small form factor, AMD dual core PC, and with Visa Premium, so it has Vista Media Center, which I am surprisingly pleased with. Most importantly, it's relatively inexpensive.

I added a video card that has HDMI out and supports Hardware MPEG2 HD and H.264 decoding, ( to connect to my new 1080p plasma. One of the features of this card is that it has a S/PDIF input to mux the digital audio channel onto the HDMI output.

The 531s has a realtek ALC888 audio chipset which supports 7.1 analog audio as well as S/PDIF I/O. (

Where I need Help
The mobo only has analog output support from the manufacturer. In examining the mobo, there are S/PDIF solder points next to the onboard VGA adapter. I'd like to be able to tap into these and pass the AC3 audio onto the video card to be muxed into the HDMI cable and be passed onto my DSP.
How do I tell which of the solder points is the ground and which is the signal?
I've attached a picture of both top and bottom pics of the mobo mount area.

Thanks for the help!


  • spdif out.jpg
    spdif out.jpg
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In the top pic the small pad on the left has four small traces running from the pad to the surrounding ground plane, so that is the ground.

I'm far from an expert ont the subject, but you might need a resistor in series with the output an/or prefferably a SPDIF transformer.:confused:

EDIT: Actually, after looking at the pic more, there might not even be a signal present there. It looks like there are other missing components that the output might rely on.