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I am considering a Terratec 24/96 card, or simply a card with optical out. Will there be any advantages at all when I am only using the card for DVD playback? Isn't the signal sent right through anyway (with no A/D or D/A conversions)?

 

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I upgraded from a SB Live 5.1 to the Terratec 24/96. I noticed a big difference with WMA files, but with DVDs the difference was much less. The other advantage is that the Terratec uses toslink rather than the doggy voltage coax link on the Live.


Jeff
 

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Thanks. The alternative card has optical out as well, so the doggy mini-jack SB Live! is not a problem...


I think I'll go for a simpler card, given the fact that I'm only using the card for DVD playback and some gaming...
 

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Beware of the jitter-prone toslink interface! In the audiophile community, toslink is generally rated as the Crappiest Digital Interface On Earth. I understand that the complete electrical isolation of an optical interface seems a good thing, but in practice this has a relatively small influence on SQ. Jitter OTOH has not.


[This message has been edited by Iceman (edited 07-04-2001).]
 

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I found DVD playback via the M-Audio Spif to be significantly superior to the SBlive via hoontech.


Less hum, more detail less jitter.


The SBlive is a noisey card IMO and it was not as smooth sounding as the 2496.


Cheers Rick
 

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I also have the M-Audio in my new HTPC. I have to say using the S/PDIF digital out to my lexicon MC-1 has produced the BEST audio of any device I have ever had plugged into the Lex. That includes two different DVD players and a LD player. The steering is precise, dynamics outstanding with a wide sound stage and the low freq's are very tight. DVD has NEVER sounded this good. The M-Audio card using WinDVD never has a problem syncing to 5.1 or DTS.


However I think this comes at a price. I so far haven't been able to get an older game "Rogue Squadron" game to give me un garbled audio in eather the Digital or analog output.


Don
 

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Quote:
Originally posted by Iceman:
Beware of the jitter-prone toslink interface! In the audiophile community, toslink is generally rated as the Crappiest Digital Interface On Earth. I understand that the complete electrical isolation of an optical interface seems a good thing, but in practice this has a relatively small influence on SQ. Jitter OTOH has not.


[This message has been edited by Iceman (edited 07-04-2001).]
Only a problem with cheap toslink cables. Supra make very good Toslink cables.


Jeff
 

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This jitter stuff just keeps floating around. If you had jitter, then either the signal to noise ratio would go completely to hell or you would hear lots of pops and clicks. There may have been jitter problems 20 years ago, but there aren't any now. Here's a test you can try, if you're willing to spend a little time to learn how unlearned the "audiophile" community actually is. Using

DAE on your cd burner, make a copy (I use EAC)bit for bit

of any audio cd. Make another from that copy and so on until

you've made about 20 copies (I did 25). Then have your significant other play back the original and the 25th generation thru your hifi without telling you which is which. If you can easily tell the difference then you can

reassure yourself that there's jitter in your signal chain.

When I did it I couldn't reliably identify the original from

the copy so I'm happy that my system has inaudible jitter (or that the whole thing is a bunch of smoke to sell expensive cables an DA/AD converters).

Rgrds-Ross Salinger
 

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I don't think that there is any reason to believe that packetized audio data from either DTS or Dolby Digital on DVD will or should sound different through a 24-bit audio card.


That being said, I did purchase a 24-bit audio card for my HTPC because I wanted bit for bit accuracy on on packetized data. (DTS CD's)


Jeff Hipps
 

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To answer the original question: yes, but not because of their 24-bit support. Ie, cards like the Terratec are simply much higher-quality pieces of equipment than consumer gear, but no discs will actually output 24-bit audio (at least until computer-based DVD-A catches on).

Quote:
Here's a test you can try, if you're willing to spend a little time to learn how unlearned the "audiophile" community actually is. Using

DAE on your cd burner, make a copy (I use EAC)bit for bit

of any audio cd. Make another from that copy and so on until

you've made about 20 copies (I did 25). Then have your significant other play back the original and the 25th generation thru your hifi without telling you which is which. If you can easily tell the difference then you can

reassure yourself that there's jitter in your signal chain.

When I did it I couldn't reliably identify the original from

the copy so I'm happy that my system has inaudible jitter (or that the whole thing is a bunch of smoke to sell expensive cables an DA/AD converters).
You misunderstand what jitter is. It cannot be stored on CDRs, nor is it a generational loss - the bits are always correct (at least if you use EAC).


Rather, it is a problem with the timing in digital transmissions; and since 99.9% of DACs that I know of derive their clock from the source signal (via a PLL if you wanna get technical), jitter becomes a factor.
 

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Actually I do understand that jitter is a timing error. However my point is simply that, if a timing error exists such that it is caused by a cable, then reusing the cable (or circuit) over and over again wil exacerbate the error to a greater degree. More and more timing errors will occur and the recording will become unlistenable. When data is transmitted digitally there has to be a clock. Between a CD player and a receiver I understand that normal practice is for the receiver to receive the clock signal from the CD player. If there is jitter in the transmission, either the error recovery scheme will resurrect the correct bit pattern (and you have effectively perfect transmission) or you will get noise and distortion. If you apply this same logic to the recording chain test that I mentioned, then you arrive at my conclusion that the test I did is valid. I'd love to learn something new. My point had only to do with the question of audible jitter being present in cables. It can't just be a "one time" error; once I record, if the timing is wrong than the bits cannot be laid down correctly. It's always been my understanding that the only place jitter effects could really occur subtly would be when the signal is clocked out of the buffer to be processed by the DAC into music. The question pertained to transmission in the digital domain.

Rgrds-Ross Salinger
 

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Quote:
It can't just be a "one time" error; once I record, if the timing is wrong than the bits cannot be laid down correctly.
In short, yes they can. If anything, the old consumer notion of "digital is digital" applies. Timing data is only applicable when attempting to play the sound through a DAC.


There's a reason you never hear about "jitter" issues on the IDE, SCSI, PCI, etc. etc. busses.


(Edit: I checked out the above link - it's pretty good and says much the same thing.)
 

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Cliff,


An excellent URL, thanks. I take the liberty of showing the

reply the author made to a question regarding the audibility of jitter in cables. I think that this reinforces my point about reasonably well made cables having no sonic significance with regards to jitter even if they are jittery.


I've now got to read thru carefully to decide whether I agree (or can refute) the idea that there are "jittery" cd's out there. I wish there was some more detail (for the skeptic in me) on the blind test the author experienced at the pressing plant and some independent corroboration.


>>>>>>>>>>>>>>> >>>>>>>>>>>>>>> >>>>>>>>>>>>>>& gt; >>>>>>>>>>>>>>& gt;

Dear Grant:


This is ultimately a jitter question, you know. My answer is that the apparent sonic differences between interface technologies such as Toslink, glass, and copper are IRRELEVANT when doing transfers or when passing signal from one processor to another. You can forget about that question with COMPLETE CONFIDENCE----since all of the technologies are capable of passing perfectly good data, within their specified cable lengths. Remember: the clock is not transferred along with the data. Only the data is transferred to the processor's circuits.


The apparent sonic differences between interface technologies come into play in only ONE place.... and that is at the input to the converters (A/D and D/A).


If the D/A is susceptible to jitter on its digital inputs (as most are), then you will hear differences between toslink (plastic fiber), glass fiber, and copper (hard wire). Some D/As reject jitter better than others, and that will determine the extent you can hear these differences. REMEMBER: This is only important to that particular listening session (the D/A only) and not to any other circumstance.


In the case of an A/D, if placed on internal sync, then its jitter (and subsequent distortion) is totally determined by its internal clock ciruits. But if you have to lock an A/D converter with external "AES" sync, the interface technology chosen may affect the stability of the A/D. Locking an A/D with wordclock produces far less jitter because there is no audio on the wordclock line, it is a pure clock. Wordclock is the second-best way to lock an A/D short of using internal sync. In the case of AES/EBU, the audio and clock are on the same line, and the audio (and other data) can cause interference during the critical clock extraction process. The different technologies (toslink, glass, copper) have different bandwidths, and reduced bandwidth (as with plastic fiber) can cause greater interface jitter.

>>>>>>>>>>>>>>> >>>>>>>>>>>>>>> >>>>>>>>>>>>>>& gt; >>>>>>>>>>>>>>& gt;

Rgrds-Ross Salinger
 
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