Spdif AC3/DTS

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madad

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#23246 23-Jun-2008 15:49

Hi there, I'm trying to find a decent pci card that I can use to output sound to my amp that only has a digital spdif input. (Optical). I bought one off trademe only to find it only spits a 2 channel signal out of the spdif, so I'm expected to use the analog outputs for a surround signal. What a waste of money! Urgh.

Can anyone suggest anything? Cheap would be good otherwise I may as well upgrade the mobo to one with spdif on board..

Cheers!

sbiddle

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#139961 23-Jun-2008 15:57

What type of chipset does it have? There are a lot of cards that use a C-media chipset (the DSE one included) that only support 2 ch SPDIF with the C-media drivers but there are 3rd party drivers that allow full 5.1 passthru.

If you do have a C-media 8738 or 8768 the 3rd party drivers are available here. If it's a different chipset you will have to ignore everything I've said but there are a lot of PCI sounds all based on these 2 chipsets.

askelon

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#139968 23-Jun-2008 16:21

What are you trying to do? AC3/DTS should automatically be decoded via your AMP - any optical output with any card should handle that with no problems. If your trying to get 5.1 with say a game then you'll need to get a sound card that supports Dolby Digital Live which encodes the signal to AC3 on the fly - from memory only very certain sound cards support it - the creative labs ones should and a few select cmedia chipsets.

madad

75 posts

Master Geek

#139970 23-Jun-2008 16:29

Yeah it is a dick smith card with the c-media chipset. I stumbled over the drivers you've linked to but after instaling i get intermittent sound. eg the startup sound in windows only starts playing half way thru. Then when I started playing tv it produced no sound and the machine cannot make any sound til I reboot, so I assume it's not working very well.

I simply want to pass all sound out over spdif. stereo, ac3, dts, the whole lot. It's a secondary media pc I'm running in my bedroom so no need for games. Just pure media portal stuff.. tv.. dvds.. music

Cheers for the help!

sbiddle

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#139983 23-Jun-2008 17:11

askelon: What are you trying to do? AC3/DTS should automatically be decoded via your AMP - any optical output with any card should handle that with no problems. If your trying to get 5.1 with say a game then you'll need to get a sound card that supports Dolby Digital Live which encodes the signal to AC3 on the fly - from memory only very certain sound cards support it - the creative labs ones should and a few select cmedia chipsets.

The issue is that the drivers for this particular chipset only supports 2ch SPDIF - it does not support 5.1 passthru. This is why somebody has written 3rd party drivers for it to enable 5.1 passthru.

I played with the drivers many months ago on a DSE card and they worked perfectly.

madad

75 posts

Master Geek

#140058 23-Jun-2008 22:17

Well that was pretty frustrating. I can now play a dvd in powerdvd and get proper 5.1 surround working through the dick smith card. But it won't produce any stereo signals... when I try and play any recorded tv it produces no sound at all.

Any ideas? I'm using the 3rd party (google code) drivers..

richms

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#140077 24-Jun-2008 00:42

I would suggest getting a card or motherboard with an encoder in the manufactures drivers so you can get some support on it.

I have a cmedia card that I use because its one of the few that will do bit accurate playback at 44.1kHz for all the DTS cd's I have on the computer.

I have in the past used my old nforce 2 which has dolby digital encoding on it, and my new gigabyte 780g board claims to have dts encoding on it (never tried it) - but the gigabyte motherboard costs about the same as the cheapest card I have seen with it on it so a new mobo may be the easiest option assuming the rest of your hardware will work in it.

edit:

actually that site says those 3rd party drivers dont support dolby digital live encoding so wont help you at all, and the ac3 passthru on the stock drivers has always being fine when I have tried it.

You may be able to get 5.1 encoding working for playing back movies with media player classic. I know I eventually got it reencoding 5.1 aac soundtracks to dolby digital with the ac3 codec somehow, that was before I got the analog cables so I didnt have to mess around with that carryon.

Richard rich.ms

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madad

75 posts

Master Geek

#140097 24-Jun-2008 09:16

Hey thanks for al the help everyone, seems I'm not the only one that's been down this road!

I got it all sorted this morning, much to my pleasure! I read some stuff on the google code page that explained what to do if there was no sound on analog sources and one of the things it suggested was making sur ethe sound setup in windows was set to stereo speakers. I set that and hey presto, I now get analog sources such as tellie coming from both front speakers and 5.1 digital signals being processed properly by my amp.

Very pleased with the result, for a very cheap sound card, and of course chuffed I don't have to go out and buy a new mobo!

Now, I just need to get the whole rig working with my picopsu!!