SPDIF output from computer

Hi all

Hopefully someone might be able to shed some light on a little problem I'm facing

I have a brandname PC (NEC, Packard Bell...same thing) which I'm setting up basically as an entertainment PC (ok, dont roll your eyes). It is an MSI mainboard produced specifically for the brand and MSI website has little to no useful info on the board.

Natrually I have no information as to the connectors on the mainboard of this PC but have concluded that the onboard SPDIF output connector comprise a 3 pin header GND, signal & +5V. I made an assumption that the output level would be a standard. When connected to my amp (all sheilded / coax cable) I do get all the right indications as to DD, DTS, PCM etc. and the audio all comes from the correct speakers (and sounds a damn side better than using the 6 analogue outputs from the shitty onboard amps through the 6CH input on the amp). However I do get faint clicks & pops...certainly not normal, and when I played back a recording I had made from my camcorder (in DD 5.1) there was at one point an audio dropout of a couple of seconds.

I havent dragged a CRO home yet to look at the signal, but am beginning to wonder as to whether the output is TTL instead of the typical SPDIF level. Anyone have any ideas? Maybe TTL to be connected to a toslink module?

Thanks in advance James

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James
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On Sun, 7 Jan 2007 21:27:00 +1100, "James" put finger to keyboard and composed:

Identify the sound chip. Its datasheet will often have an application circuit or reference design.

- Franc Zabkar

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Please remove one 'i' from my address when replying by email.
Reply to
Franc Zabkar

Thanks

I tested the output last night and it is indeed a TTL signal. The simplest solution would have been to connect straight to a Toslink TX module (I didn't have any DVD players laying around that were otherwise useless though) and use optical but instead knocked up a crude but effective converter to hookup to the coax input on the reciever (There are a couple of simple circuits floating around on the web for buffering & crude impedence matching). The thing does however work a treat.

James

Reply to
James

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