(I hope this is the right forum for my question. In any case, my ignorance of PC surround sound output has become apparent. ;))

I just purchased a Dell Inspiron Desktop 531S. It's my intention to use this small PC as a simple Home Theater PC by connecting it to the entertainment center in my family room.

My entertainment center includes a Sony STR DE-875 surround sound (5.1) amplifier which has an overwhelming (to me, anyway) number of inputs. My existing A/V components' audio connections to the amp are via Toslink (for a DVR and an Xbox 360) cables and via a coaxial (for a DVD player) cable. The A/V components' video connections go directly to my HDTV.

In my haste to purchase this PC, I neglected to give thought to how I would connect the audio to the amp. The PC came with an integrated sound card that supports up to 7.1 output; however, this support is through three (for 5.1--front, center/sub, rear) or four (for 7.1--front, center/sub, rear, side) patch cables--not Toslink or coaxial.

Is this type of PC audio output compatible with standard amplifiers--including my own? How do other forum members connect their PCs to their entertainment center?

BTW, I noticed that Creative Labs has a compatible (i.e., low-profile) sound card that supports SPIDF; however, their web site indicates that an add-on is required for digital output. I don't necessarily need digital output; I just want to be able to connect this PC to the amp and get decent sound.

I've just started looking into this tonight and came across this.

http://www.sondigo.com/store/main?region=na

Maybe that will get you started.

Check into the Auzentech line of soundcards!

These cards will give you 5.1 from ALL of your computer sounds in Dolby Digital and DTS from a single toslink or coaxial connection.

I have the Auzen X-Meridian sound card and not only do you get audiophile grade sound quality and Dolby and DTS ENCODERS, but you get it at an UNBEATABLE price!

Trust me when I say look into Auzentech sound cards, you'll be unable to thank me enough! :D

The main idea here is to get a sound card that has ENCODERS not just decoders! That way ALL your sound is in 5.1 or 7.1 not just your dvd's you watch on your computer!

-Brian

Or... just you run three pairs of analog audio cables from the PC's audio outputs to the "MULTI CH IN" on the back of the receiver.

Refer to page 11 of your receiver's manual for an example.

Yes, do that if you want stereo sound from your computer and mp3's and everthing but your DVD's you watch on your computer in crappy analog sound through a crappy little soundcard

Or... get a good soundcard now and never worry again! :)

What needs to be "encoded" for DD/DTS? If the source material is from a DD encoded source (digital TV, DVD, games, etc.) it seems like having an encoder is moot. That is unless you need to perform your own recording and mixing for audio.

Be that as it may... the OP has an option to buy a sound card for $150+ or the audio cables for ~$10. ;)

Most source material is NOT DD/DTS, such as mp3's most computer games, youtube or internet movies and or music; actually, almost everything.

Also, if the OP wants any form of quality from his PC to his home theater system then he needs a higher quality soundcard than some POS Dell onboard garbage.

You get what you pay for! ;)

I guess my point is...

If the OP is using his PC as a "media center" and uses it as a primary source for gaming, music and video, then you may have a good recommendation. If the OP wants to get an inexpensive and less intrusive connectivity option for audio from the PC to a A/V reciever, then three audio cables may suffice as a more cost effective solution.

No one knows exactly what the OP's requirements/desires are, so no need to persist.

Option 1
purchase the new sound card. install in the pc. setup options/software/drivers. purchase and install one digital audio cable. Approx. cost ~$150 and time for installation/setup.

Option 2
If you have three pairs of audio cables laying around, free.
Need audio cables.... <$10 from monoprice.com

And I agree completely. I saw the words "Home Theater PC" in his original post and jumped on the idea of having a more "theater" like experience; which would in most people eyes have DD and DTS as standards, not options.

I suggested that he "look into" the Auzentech cards as an option to acheive a more theater-like experince for his home theater system.

If he had said he just wanted to use some silly computer speakers instead, then I would have posted the same thing as you, just grab some 3.5mm cables and "there-ya-go"!

I do want to apologize to you though if in my previous posts or even this one if I seem a little rude, I'm not trying to be, I just get excitable when people mention home theater and I have a chance to show them a alternative solution that they may have not thought about or known all the details about.

I know that myself, I've went through countless sound cards back in the day, trying to acheive 5.1 from my computer only to be continually dissappointed by bad labeling on products and such. I suppose I'm just trying to offer anyone who will listen a viable shortcut so that they don't have to go through endless Creative Labs sound card swapping only to be dissapointed!

-----------

So, to the original poster...

If you just want blips, bleeps, and "some" DD/DTS from your computer, and don't want to shell out too much money, jump all over Ratman's idea of standard cables.

If however you think you might want something more, check into the cards I suggested and learn the difference between "decode" and "encode".

Either way, you'll surely enjoy the experience!

-Brian

Thank you, kamui and Ratman! I appreciate your responses. I'm also glad to learn that I asked this question on the right forum.

I wouldn't call myself an audiophile. I have a decent Klipsch 5.1 speaker system connected to the Sony amp mentioned earlier. It sounds great with DD/DTS content whether from DVDs or the HD DVR.

I'm hoping to use this PC to be the primary means of playing my large MP3 collection in my family room--where my family and company spends the most time while in the house. I'm also hoping to use this PC to play AVI (mostly DIVX) movies and TV shows that I've acquired, MPEG files I've created, and DVD content that I've converted (i.e., ripped).

If you were in my place, would you simply connect the integrated sound card to the amp....or go with a sound card?

From your exchanges, it seems as though a dedicated sound card would be required in order to hear any properly-encoded DD/DTS content to play back properly--is that the case?

Here's an added wrinkle: The Dell Inspiron 530S is a "low profile" PC--meaning that it can't house full-height cards. I went with this model because the case--lying horizontally--fits well in my entertainment center...as opposed to a normal profile PC. The Creative Sound Blaster X-Fi Xtreme Gamer (http://us.creative.com/products/product.asp?product=15853&category=209&subcategory=669) that Dell recommends is a low-profile card. OTOH, that card may not add much over the integrated sound card and/or may be a bad sound card choice. In any case, I'm nearing the end of Dell's 21-day return period, so if I'm going to return this PC and go with a normal profile model, I need to do it soon.

Perhaps the simplest thing to do is to 'connect three pairs of analog audio cables from the [integrated sound card's] audio outputs to the "MULTI CH IN" on the back of the receiver' and then see how well/poor it sounds. (Thanks for pointing me to the appropriate page number in the amp manual, Ratman.) It's not clear to me, however, what the interface is for the MULTI CH IN ports on the amp. Are they 1/8" stereo plugs? RCA? Coaxial? Also, the MULTI CH IN section has *six* inputs--FRONT L&R, REAR L&R, CNT, and (I believe) SUBWOOFER. How do I convert three 1/8" stereo outputs from the integrated sound card to these six inputs? The people at my local Radio Shack and BestBuy (PC and HT sections) didn't know...nor did they have much in stock that looked like it work. Creative has a HT Cable Kit (http://us.creative.com/products/product.asp?product=14309&category=1&subcategory=16) that might do the trick--but their disclaimer indicates that the kit is only for use with their sound cards.

Thanks again for your help!

No you don't need a dedicated sound card to get DD/DTS from pre-encoded sources.

In other words, if your movies already have DD/DTS then you just need to connect the analog cables to your HT.

The onboard and the Creative sound card you mention will only allow you to listen to non pre-encoded sources (such as mp3's) in stereo, even if you have all those cables connected.

Also, there are all sorts of cables and connectors you can use to convert mini jacks to RCA connections for your home theater and I'm certain any radioshack would have at least a few of these!

One is a cable that just has a mini jack on one end and two RCA cables on the other.

The other is an adapter that has a mini jack male connector and two female RCA connectors on the other end, adapter is about 1" x 1" big, so you don't need anything fancy for that.

Hope it helps.

-Brian

---------------

Edit: Here's an example...

http://www.radioshack.com/product/index.jsp?productId=2103710

Or this...

http://www.radioshack.com/product/index.jsp?productId=2103859&cp=&sr=1&origkw=right+angle+1%2F8&kw=right+angle+1%2F8&parentPage=search

No you don't need a dedicated sound card to get DD/DTS from pre-encoded sources. In other words, if your movies already have DD/DTS then you just need to connect the analog cables to your HT.

The onboard and the Creative sound card you mention will only allow you to listen to non pre-encoded sources (such as mp3's) in stereo, even if you have all those cables connected.

I'm confused by these two paragraphs; please bear with me. Will my onboard card, by itself, using analog cables, provide DD/DTS if the source content is encoded that way? If so, what is the advantage of a digital (optical or coaxial) connection over an analog connection? And what is the advantage of the signal coming out of the Creative or Auzentech over the signal coming out of the onboard? A better quality of signal, primarily?

Thanks for the pointers to the items at Radio Shack. The second item (6-Ft. Y-Adapter, 1/8" Right-Angle to Two RCA Plugs) looks the simplest. I would need one of these for the Front and one for the Rear; but how is the sub/center handled? Do I use a third one of these adapters to split the onboard's Center/Sub signal into the two inputs on the amp?

Yes, if the source content has DD/DTS encoded on it already, then using those cables will give you discrete 5.1 sound!

The advantage of digital is less chance of interference from outside sources, such as the interference a PC can create.

The advantage of a discrete sound card is MUCH better quality and you release the sound processing taxload off the PC, thereby increasing your computer speed.

Usually on a 5.1 sound card there are three mini-jack connectors one for front L/R one for surround L/R and a third connector for center/SW!

You'll just have to go into whatever program came with your sound card or onboard sound properties and enable the correct settings.

So yes, you need three of those cables for 5.1 from analog from your computer.

-------------

Edit: Or you could just get an Auzentech card, a single digital connection to your home theater and 5.1 DD/DTS from ALL your content and never worry again :D

Thanks. My local RadioShack has plenty of the Y-adapters that you mentioned. I'm headed there now to buy three and will then try it with my system.

I've never used the MULTI CH IN interface on this amp. I'm hoping it won't be too much of a challenge to configure it to use that input. :)

If the sound is less-than-stellar and I end up having to purchase a sound card, the Auzen X-Meridian sounds like a good choice. Do you have a source for it? NewEgg lists it as discontinued and no longer available.

Creative's card is low-profile; do you know if any of Auzentech's are, too? If they aren't, then my options are limited: go with the Creative and try to figure out their interpretation of 'digital out'...or exchange the PC for a normal profile model so that it can house a normal profile card like the Auzentech.

The X-Meridian is discontinued like you said, they do however offer the X-Plosion Cinema which I believe is cheaper and then there's the X-Fi Prelude which is their best one I reckon.

My suggestion would be to go ahead and try the analog connections and see what you think, if you feel it's still lacking what you might desire then look into my suggestion.

They are NOT low profile cards, so you would have to get another computer I suppose if you went that route.

-Brian

to be aware....

A new sound card will not "magically" transform MP3's or non-DD/DTS encoded source material(s) into discrete surround. The best you may be able to do is apply DolbyProLogic for a "matrixed" surround field. It may be better or worse. You will be be at the "mercy" of the quality of the source material. Sometimes "stereo" sounds better as "stereo". ;)

The X-Meridian is discontinued like you said, they do however offer the X-Plosion Cinema which I believe is cheaper and then there's the X-Fi Prelude which is their best one I reckon.

My suggestion would be to go ahead and try the analog connections and see what you think, if you feel it's still lacking what you might desire then look into my suggestion.

They are NOT low profile cards, so you would have to get another computer I suppose if you went that route.

-Brian

Thanks. Good to know.

I wasn't really looking to 'build my own' media center / simply HTPC, but that's the way it might turn out to be!

to be aware....

A new sound card will not "magically" transform MP3's or non-DD/DTS encoded source material(s) into discrete surround. The best you may be able to do is apply DolbyProLogic for a "matrixed" surround field. It may be better or worse. You will be be at the "mercy" of the quality of the source material. Sometimes "stereo" sounds better as "stereo". ;)

Thanks. I'm not looking to enhance the audio of any of this content; however, I would like to be hear the content in its native sound, whatever that might be. :)

to be aware....

A new sound card will not "magically" transform MP3's or non-DD/DTS encoded source material(s) into discrete surround. The best you may be able to do is apply DolbyProLogic for a "matrixed" surround field. It may be better or worse. You will be be at the "mercy" of the quality of the source material. Sometimes "stereo" sounds better as "stereo". ;)

You should REALLY check into these sound cards; it's a LOT more than a simple pro logic or neo:6 simulation, I have YET to hear ANYTHING that sounds better in it's original stereo source ;)

-------------

Edit: I should mention that I "only" have a $1500 SVS 5.1 sound system and maybe it's not "high quality" enough to hear how bad it supposedly should sound :p

I have had a LOT of people hear my system and every single one of them was blown away by the almost "magical" ;)
sound my simple MP3's were reproducing!

I've been through plenty of creative labs soundcards and many others in my time and NONE were anywhere NEAR the level of quality the Auzen's are capable of...

Anybody who's heard it seems to agree too... just a thought

-Brian

I would disagree... two channel source material is just that and nothing more. Any "logic" that is applied is a manipulation of the original material to produce an effect. (which is DPL or NEO)

You can possibly "enhance" the original 2 channel source material and it may create a "wow/surround" affect. But, you can't make a silk purse from a sow's ear. (especially with ripping to MP3).

I know you are happy/excited about your sound card and it's probably very good (price/performance). I just want to keep the terms and expectancies on the "up and up" so the OP can make an informed descision.

LOL!

I REALLY wish you had the ability to hear these cards on even a decent home theater.

I 100% agree with what your saying, I personally can not stand applying dolby pro logic and neo:6 to stereo music if I'm doing any sort of critical listening.

I can not stress enough that this is NOT the same, not even in the least!

I suppose I just sound like a fanboy, but again, if I could have saved money and just used a cheaper solution I would have been all over it! I use these paticular cards because they really are far above and beyond any others...

These cards use Dolby Digital Live (previously Dolby Interactive Content Encoder) and DTS Connect, and it's NOTHING like pro-logic/neo:6...

I'm just offering the OP a "shortcut" so that he doesn't have to go through all the searching and constant dissapointment I did...

If you asked me about 2 years ago, I would have said EXACTLY the same things you are saying... I just can't describe it because indeed it doesn't make sense. Technically speaking, what I'm suggesting is just plain wrong.

But it is anything but, and I suppose the only way for you to know that is to hear it yourself... I SWEAR some MP3's sound almost like SACD's (and that statement alone should indeed be enough to warrant you not trusting anything I say :p )

You are correct though Ratman, the OP will be quite satisfied with what he will acheive via your suggestions, so to him I say "enjoy!".

DDL and DTSCon are great for gamers if they want to connect one digital audio cable from the PC to the A/V receiver.

Does DDL and D-Con "encode"? Sure they do! Because they essentially convert an analog 5.1 audio and encode to a digital bitstream that has to be de-encoded by the A/V receiver.

IMO... it's a matter of convenience, not a technical/audio breakthrough.

And again... if the source material is not "discrete" (I.E. 2 channel/stereo), any surround effects with have to be performed by DPL or NEO.

I'll just agree with you; I doubt I know enough about all the aspects anyways...

One neat thing I want to mention though is that the original Xbox used D.I.C.E (DDL)

I think I would like to agree with you but say that there are four options for stereo sources:

Dolby Pro-Logic
DTS Neo:6
Dolby Digital Live
DTS Connect

Out of those options, I suppose all I'm saying is that DDL/DTS-C are the much better choices.

It seems like you are saying DDL is just a connection and that pro-logic/neo:6 are what are then applied.

To clarify; DDL is ANOTHER form of matrixing, not just a name for a digital connection..

And if I had to choose a matrixing form for my stereo music, I would EASILY take DDL/DTS-C over pro-logic any day.

But yes technically ANY matrixing is distorting the original content, I just think the DDL/DTS-C do it in a highly pleasing fashion that does not detract but enhances the original stereo signal...

Then again, maybe it's just me and everyone who has heard it....

kamui: May I ask what method you use to connect your Auzen to your amp?

I've been looking more closely at my amp and now wonder whether I have enough digital inputs. The digital ports on my amp are listed as OPTICAL DVD IN, OPTICAL TV/SAT IN, OPTICAL MD/TAPE IN, and COAXIAL DVD IN. There's also a OPTICAL MD/TAPE OUT port. So it appears that there are only *three* digital inputs, with the DVD input being either optical or coaxial.

My DVD connects to the COAXIAL DVD IN, my DVR connects via the OPTICAL TV/SAT IN, and my Xbox 360 connects via the OPTICAL MD/TAPE IN. So even if I were to go with a sound card that has digital output, I don't think I'd be able to connect it to this amp. :(

OK, I'm currently listening to the results of using the onboard's analog outputs with the MULTI CH IN ports on my amp--using the Y-adapters.

It took a bit of work to figure out how to hear the audio. Up until now, I've always used the amp's FUNCTION knob to cycle through the various audio sources; however, that doesn't seem to provide a means to access the MULTI CH IN signal. Near that knob is a small button labeled "MULTI/2CH A. DIRECT". When I press this button, it mutes whatever audio source was previously selected via the FUNCTION knob and then cycles between "MULTI CH DIRECT" and "2CH ANALOG DIRECT" settings. The audio from the sound card is only heard when I select "MULTI CH DIRECT".

The audio sounds fairly good; however, nothing seems to be heard from the center channel or subwoofer--whether playing MP3s or videos. I verified all of the cable connections. When I use the onboard's test utility to send a signal to all five speakers and the subwoofer, audio is heard from all of them. When I use Vista Media Center's speaker configuration tool, select "5.1 speakers", and then perform a speaker test, sound is heard from all five speakers, but not the subwoofer; however, it's not clear whether the subwoofer is actually included in that test. In any case, for both the onboard test and Media Center's test, I can hear sound from the center speaker.

Is it normal--with my configuration, as described--to *not* hear audio from the center speaker? I'm stumped as to why the *tests* produce sound on the center speaker and subwoofer, but no content seems to produce sound there.

The only thing I could think of is that some settings somewhere is not configured properly.

Most likely whatever program you are using to watch your DVD's on, is not configured for 5.1.

I use WMP 11 and I'm pretty sure I had to make setting adjustments in the program itself.

Also check the sound properties under the control panel, to make sure that all looks like it's set up for 5.1.

And don't take this the wrong way, but also make sure you're using 5.1 DVD's and that you are selecting a 5.1 track to listen to.

Also make sure you visit the Dell website and you have all the latest drivers..

I really hope some of this helps, if not keep firing away questions and I'll do my best to answer them.

-Brian

Thanks, Brian. Definitely helpful advice! Hopefully, other newbies and/or people with the same kind of configuration find this helpful, too.

I can understand the lack of output to the center speaker. What *really* stumped me, however, was the lack of bass / output from the subwoofer even when just playing MP3s. It's almost as though the subwoofer channel wasn't getting much / any signal. I tried WMP11, also; however, I don't believe there's a place to select a speaker configuration. There is the "SRS WOW Effects", which include "TruBass", but this didn't seem to have any effect.

I tried various settings on the amp before giving up last night. This morning, I noticed that even my DVR wasn't generating any bass. I went through the settings again and noticed that I had somehow stumbled upon a setting that had resulted in very limited bass! After correcting this mistake, I had bass again with my DVR....and with my PC, also!

I'm listening to MP3s now while I work in the other room. IMO, the sound--while decent--seems a bit muffled. I'm not sure if that's due to my being in the other room, that the signal is coming out of a lowly integrated sound card via analog cables, or whether it's just my imagination--perhaps influenced by the comments in this thread. ;)

LOL! :D

I'm glad you got it working... I remember back in the day all the times I went through problems fixing all sorts of settings.

Connecting a PC to a home theater and getting what you think it should be can prove to be quite a daunting task, as I'm sure you're learning! :p

I would also recommend you check out the other sections of this forum for advice on what settings to use for a HT Receiver if you haven't already.

When properly calibrated, the sound you can acheive can be quite phenomenal

Also do NOT enable SRS WOW Effects or any other enhancements like that because it destroys the original material, if you think it honestly sounds better with them on, then that's the first sign you don't have a properly calibrated HT!

Use a Radioshack SPL meter and continue to fiddle with settings in your computer, and just leave enhancements off (funny coming from me after all I've said about DDL/DTS-C! :p )

Best of luck

PC to HT should be enjoyable not just a job!

-Brian

Thanks for the encouragement!

Is it possible that with the analog cables the full signal range is not being passed through to the amp? I ask because the bass seems very weak. In addition: My subwoofer is configured to automatically shut off after five minutes of inactivity. When watching DVR and DVD content, the subwoofer never turns off; when listening to MP3s, however, the subwoofer turns off unless the amp's master volume is fairly high.

PC's are tuff nuts to crack sometimes. There are so many variables that could be affecting the sound.

The best solution is to figure out what's NOT causing issues, such as your DVD's are obviously not the problem, your subwoofer is not the problem, and your receiver is not the problem, so that leaves either your sound card or your computer.

Did you check the sound properties of windows? Are all the volume sliders maxed out, such as volume control, wave, SW synth, CD Player, etc. etc.?

Also make sure you have no type of filters selected, like I mentioned earlier, they can really mess things up.

Hope something help :p

-Brian

I double-checked; all of the properties of the sound card and Windows' mixer settings are maxed out. There are numerous enhancement options available for the sound card, but they are all disabled.

I'm not at all happy with the sound card's output to the subwoofer. I'm wondering if this is just a limitation of the sound card / MULTI CH IN / analog interface?

I suppose the easiest thing would be to try analog cables with a dedicated sound card....or an optical cable with a dedicated sound card that supports digital out; unfortunately, that's not currently an option for me. :(

Check the volume/crossover settings in the A/V receiver for the subwoofer and the sub itself.

If all other materials sound okay from the PC, perhaps the MP3's are the weak link.

Your receiver probably does not apply crossover settings, delays, or anything else when using the Multi-Channel IN. The idea of those inputs are to bypass everything in the receiver and send the audio straight to the amplifier. All of your configuration (except volume) need to be performed on the PC. You may need to boost the level of the sub compared to the other speakers on your PC. There's an issue with a 15db discrepency between different types of audio processing that's expected to be there. I think most receivers handle this properly when sent a digital signal (they detect the format and adjust apporpriately), but if you analog out from a PC you need to be making that adjust ment in the PCs software. Someone else here may be able to explain on which sources the bass in boosted/reduced...

A mod should really move this thread over the HTPC forum...

Multi-channel using analog out tends to be poor quality from motherboards. Is there any chance you can add an SPDIF bracket to your motherboard? Check the manual and see if there is a header on the motherboard diagram. I think you would be much better served starting off with a digital connection from your PC to your receiver and the brackets tend to only cost a few dollars and add a toslink/coax digital out.

What's your motherboard?

OK, I've read through this thread in addition to others and am still confused about hooking my HTPC to my receiver (I'm also new to the HTPC thing).
I have a SB Audigy 4 sound card with an Radio Shack Phono to 1/8" adapter plugged into the digital i/o and a digital coaxial cable running from that to the back of my Pioneer receiver. First off, I'm not sure this is the correct adapter so that may be the problem.
I have Creative Mediasource installed and in the Creative audio panel I have the decoder marked as passthrough. When playing a DVD via VLC, the Dolby Digital symbol does not light up when the audio output, in VLC, is labeled as 5.1. If I change the audio output in VLC to S82/SPDIF the Dolby Digital symbol on my receiver DOES light up but the sound is horrendously choppy and unlistenable.
So, from what I've told you, do I not have the proper connection (wrong adapter?) or do I possibly have an incorrect setting. Any suggestions are appreciated. Thanks.

Check the volume/crossover settings in the A/V receiver for the subwoofer and the sub itself.

If all other materials sound okay from the PC, perhaps the MP3's are the weak link.

Thanks. I'm increasingly becoming disappointed with the sound of the receiver altogether--probably due to my fiddling with so many of the settings. Ignorance can be trouble sometimes. :)

Do most receivers have a 'reset' feature? I'm thinking that might be the best way to proceed--if for nother reason but to get the receiver back to the way it sounded before with my other sources. I'm going to look for that feature in the manual when I get home tonight.

Your receiver probably does not apply crossover settings, delays, or anything else when using the Multi-Channel IN....You may need to boost the level of the sub compared to the other speakers on your PC....if you analog out from a PC you need to be making that adjust ment in the PCs software....

Multi-channel using analog out tends to be poor quality from motherboards....I think you would be much better served starting off with a digital connection from your PC...and add a toslink/coax digital out.


Thanks. I've been wondering whether the multi-channel input using analog might be the crux of my problem.

I'm not aware of a way within the integrated sound card's settings to boost the level of the sub compared to the other speakers, but I'll double-check.

Concurrently, I ordered a low-profile sound card that supposedly supports optical out via a mini-Toslink connector (a Sound Blaster XtremeGamer 7.1). I figure this is worth a try before I give up altogether. ;)

If the optical connection works and the sound is good, however, I won't have enough digital inputs on my receiver--I'm going to temporarily disconnect the input from Xbox 360 to test the connection from the input on the sound card.

FYI: My receiver has audio optical and coaxial inputs for the DVD player (I'm using the coaxial connection; I figure that means the optical connection can't be used--is that correct?) and audio optical inputs for DVR and MD/TAPE (which are used for my DVR and my Xbox 360, respectively). There's also an optical out labeled MD/TAPE. So I would need yet another optical input for the sound card. Maybe I should start looking for newer, open-box receivers at my local electronics stores? ;)

OK, I've read through this thread in addition to others and am still confused about hooking my HTPC to my receiver (I'm also new to the HTPC thing).
I have a SB Audigy 4 sound card with an Radio Shack Phono to 1/8" adapter plugged into the digital i/o and a digital coaxial cable running from that to the back of my Pioneer receiver. First off, I'm not sure this is the correct adapter so that may be the problem.
I have Creative Mediasource installed and in the Creative audio panel I have the decoder marked as passthrough. When playing a DVD via VLC, the Dolby Digital symbol does not light up when the audio output, in VLC, is labeled as 5.1. If I change the audio output in VLC to S82/SPDIF the Dolby Digital symbol on my receiver DOES light up but the sound is horrendously choppy and unlistenable.
So, from what I've told you, do I not have the proper connection (wrong adapter?) or do I possibly have an incorrect setting. Any suggestions are appreciated. Thanks.

I have a Pioneer A/V Receiver hooked up the same way to my Audigy 2 ZS
and it works well with Windows XP. I don't need the xtra Creative box or
a special cable. I definitely get clear 5.1 sound with my HDTV comp tuner
or playing DVDs on the comp.

I definitely had to mess around with the AV receiver to get it all to work right.
Set everything..both in Creative and windows to SPDIF passthrough so your
receiver does the conversion.
I had to read my manual for my receiver and experiment. My receiver works
best when set to extend surround on all sources. This matrixes stereo
for music and has several choices.

Just try different settings. Mine works set to Dolby PL and surround on.
You would think this would leave plain old stereo alone but it seems to
know when it's decoding Dolby or just plain PCM and it does the surround
either way. (Dolby has better surround..plain PCM has good surround for
music without sounding intrusively worse)

If you have Vista good luck..it's gotten better but I still hate it and the big
reason my dual-boot comp runs XP mostly.

I have a Pioneer A/V Receiver hooked up the same way to my Audigy 2 ZS
and it works well with Windows XP. I don't need the xtra Creative box or
a special cable. I definitely get clear 5.1 sound with my HDTV comp tuner
or playing DVDs on the comp.

I definitely had to mess around with the AV receiver to get it all to work right.
Set everything..both in Creative and windows to SPDIF passthrough so your
receiver does the conversion.
I had to read my manual for my receiver and experiment. My receiver works
best when set to extend surround on all sources. This matrixes stereo
for music and has several choices.

Just try different settings. Mine works set to Dolby PL and surround on.
You would think this would leave plain old stereo alone but it seems to
know when it's decoding Dolby or just plain PCM and it does the surround
either way. (Dolby has better surround..plain PCM has good surround for
music without sounding intrusively worse)

If you have Vista good luck..it's gotten better but I still hate it and the big
reason my dual-boot comp runs XP mostly.
Thanks! I needed to change the AC3 filter to pass through and now it works great!

cg,

Be interested to hear how things work out when you try the digital connection. You may want to just decide on which device has the least need for digital/multi-channel output to your receiver until you upgrade. Your new card might actually have channel leveling in analog mode, might be worth checking out, creative's drivers should theoretically be much better than most onboard audio solutions and maybe you can use analog and your new card.

Also depending on your application, if you can load custom filters, like AC3filter in the audio chain you can do channel leveling/boosting that way (sometimes).