Mobo digital out? Good enough?

T

Team Obi Juan

Your Local Postmaster
Joined
Sep 28, 2005
Messages
23,276
We know that onboard analog out is often no where near as good as a sound card. My analog out has lots of feedback. Same goes for digital?

I have a biostar tforce 6100, socket 939. It has analog outputs on the rear I/O. It also has a little dongle thing that you can attach to a mobo header, that provides coaxial and optical digital out.

I'm receiving a free stereo receiver this weekend (do not know the model yet), and will be purchasing some <$150 bookshelves to go with it. (any recommendations on this while I'm here?)

My options are either to:

1) Attach the dongle. Go digital to receiver (assuming the receiver has digital in). Receiver to speakers, finished.


Or, if onboard digital sucks:

2) Buy a new full ATX mobo because my mATX mobo suffocates my video card when I put in my Audigy 2zs. Put in my Audigy 2zs, and use its digital out to the receiver.



#2 is much more costly, as I would want to go to AM2 since 939 to 939 is pretty stupid, considering I only have a 3000+... which means mobo + chip + RAM. Probably can be done for less than $200... but considering I also have to buy $150 speakers, that's pretty expensive!


Uses are 50% music, 40% movies, 10% games. More or less. This will remain a 2.0 system for the foreseeable future, unless I can find a sub and figure out how to hook up a sub to a stereo receiver that has no sub output.



Thanks!
 
If your motherboard analog out has lots of noise the digital output will probably have a similar problem, however if you can test it out that would be a good idea.

Per http://www.avsforum.com/avs-vb/showthread.php?t=690556 there are some highly rated Insignia speakers.

As far as the subwoofer goes, I hooked up a Klipsch subwoofer that had it's own crossover inside it. So your output would be Receiver->Subwoofer->Speaker, with no need for a subwoofer output.
 
Alright thanks a lot. I guess I will try out my existing set up first before I switch out mobo's so I can fit my Audigy 2zs in there.
 
If you use optical out, there is no noise. The only thing to consider when using a soundcard for bitperfect digital output is jitter, which is a very overrated concept and you'd better be substantially invested in high-end equipment in other areas of the system before you need to worry about it.

I would imagine there being minimal problems with coaxial digital output as well. I use optical and haven't done much testing either way.


rocket733 said:
If your motherboard analog out has lots of noise the digital output will probably have a similar problem, however if you can test it out that would be a good idea.

Per http://www.avsforum.com/avs-vb/showthread.php?t=690556 there are some highly rated Insignia speakers.

As far as the subwoofer goes, I hooked up a Klipsch subwoofer that had it's own crossover inside it. So your output would be Receiver->Subwoofer->Speaker, with no need for a subwoofer output.
Click to expand...
 
There is a thread at Headfi about jitter and one person pointed to an article on jitter and the engineers and sound people that tested the equipment for jitter said all midrange and up consumer audio equipment (including PC soundcards) is in the in-audible range so it is not something to be concerned about. One person in that thread claims their testing methods were flawed though but I don't know myself. I do know that digital coax has less jitter than optical and is what I use but optical has less electrical interference issues. I noticed some PC interference over analog on even my X-Fi if listening on headphones (if I turned the volume way up and nothing was playing over it, I could even hear my mouse when scrolling in web pages) but using the coax digital out to an EMU 0404 coax in it is dead silent, except when playing music. :)
 
For all practical purposes, you can assume that the digital out provides bit-perfect playback.
 
Ranma13 said:
For all practical purposes, you can assume that the digital out provides bit-perfect playback.
Click to expand...

I completely agree... Digital sound trasfers either work or don't work.... you'll get perfect or nothing. Read on only if you want the long version.

IF there was a spike of noise, you'd recieve pauses in sound rather than poor sound quality. I'd HIGHLY suspect that your comptuer would crash before sufficient noise would be made in a digital sound transfer.

If using a RCA (metal) cable to transfer this digital audio + using a reciever that had diffrent grounding than you're PC, you could concievably have a ground-loop issue, which could get picked up in your reciever on the AMP side... I'd suspect that any good amp would have noise filtering before that point though... plus, if it does become an issue, you could simply remove the ground plug from your reciever + it would fix the problem. A ground loop would not likely actually be caused by the PC or the reciever - but other poorly designed electronics that would happen to be on the same circuit.

As pointed out before you can completely remove noise on a digital connection by using optical cables - low voltage "noise" inside the PC simply cannot be sent over optical cables.. the noise would have to be bad enough that the optical tranciever (inside the PC) couldn't differenciate a signal vs this noise... and if the noise is that bad on the built in soundcard, it'd also be so on your whole motherboard - you're CPU would have issues with this noise as would your RAM... you wouldn't be doing much computing at all because you're computer would be too busy crashing + not properly booting. So all that to say - just use the friggin built in soundcard.
 
teststrips said:
I completely agree... Digital sound trasfers either work or don't work.... you'll get perfect or nothing.
Click to expand...
That really isn't true. What's important to keep in mind is that digital signals can become skewed and misrepresented -- this is known as 'clocking jitter'. These misrepresentations (generally on a <100ns scale) can yield sound quality degradation, though this is most often entirely inaudible.

While jitter's audible impact is somewhat debatable, its affect on diminishing a so-called "perfect" signal isn't. It's an entirely real phenomena and is totally quantifiable. Monster might blow it entirely out of proportion to get you to break out your credit card unnecessarily, but saying that you'll get either "perfect" or "nothing" over a digital connection is a little misleading. There are sophisticated means of suppressing jitter (some hardware will re-clock and reform the signal before conversion, like a form of jam sync), but not much consumer hardware has an effective means of jitter suppression.

999 times out of a thousand, jitter is entirely insignificant, but that doesn't necessarily mean it doesn't exist, or that it isn't always impacting the signal.
 
Hurray let's take my post, which was concise and correct, and expand upon it with 3 multi-paragraph posts that offer no real value to the thread. yay.
 
If you have issues with my posts, report them to the moderators. Otherwise, stick to the topic.
 
You must log in or register to reply here.
Back
Top