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Is All SPDIF Audio Output the Same?
CyberSpaZtiK asks: "I am going to build a Linux audio appliance to hold my music collection in various formats and for output to my stereo system. Because of a probable lack of Linux availability or support for audio cards with high quality D/A converters and low-noise electronics (or am I mistaken?), I want to keep the output path completelely digital by using a card with SPDIF output. However, it occurs to me that I actually know very little about SPDIF - are all SPDIF outputs made equal? Can I expect every SPDIF interface to emit the exact PCM data of the source audio, or are there over/under-sampling/aliasing, etc. issues that you sometimes get with digital signal processing? What do I need to understand about SPDIF and/or other digital output interfaces to make an informed decision?"
SPDIF outputs are usually pretty consistent at passing the PCM data or the DD/DTS sountrack if you have them configured right.
Some cards, however, such as Creative's Audigy series, are notorious for resampling inputs/outputs, so you might want to check.
Even a cheap card, like the $15 cards on Newegg, should provide a clean output. Don't buy the garbage about "jitter" that I'm sure someone will bring up - so long as your card and cabling are operating within the specification, you won't have any problems.
Do consider TOSLINK instead, however. TOSLINK uses fiber-optics, so your audio equipment and PC are electrically isolated. This reduces the chance of creating a ground loop or introducing RF noise into your reciever/amp. Moreover, it protects your equipment in the event of an electrical mishap.
It will occupy you for years to come.
Then why do they have an "Ask Slashdot" section?
Chaintech's product page
Hey shithead - Slashdot discussions answer plenty of questions like this. YOUR answer is entirely useless, and poorly worded to boot.
"read errors and the like" - Brilliant, thanks. Why don't you post under your member name so I can come kick your ass.
Jitter is a problem for electrical engineers and programmers. By the time we're done with the system, you won't be able to tell whether there is any jitter or not, nevermind how much. Regardless, there WILL be jitter.
Unless, of course, all your units have synchronized clocks, or each have their own atomic clock.
Unlikely, to say the least.
Jitter is not a problem the average prosumer really needs to worry about, nevermind the average consumer.
The audiophiles who care about it care the same way about their tubes, oxygen-free cables, and green highlighters. Whatever gives you a warm fuzzy feeling, man.
But, technically, it does exist, and it is a problem that results in either doubling up on samples, skipping samples, or some sort of macabre clock synchronization scheme that only ends in tears.
Only, technically, that's not jitter either.
-Adam