S/PDIF question

[MowSow]

I searched the entire forum for information on connecting the my DVD player in my PC to my S/PDIF sonnector on my Sound Blaster, but I could not find an answer.
Is there really an advantage to doing that, oppsed to enabling digital audio in windows for that DVD drive ? is it easier on the PC to use a cable instead of having the CPU do the work !?
TIA

 

[Auric]

If the S/PDIF cable is used then the signal is sent directly and so does not subject the bus to any load and is the preferred method. Neither is required for DVD movie playback.

 

[CigarSmokedByClinton]

AFAIK, It doesn't take CPU cycles to enable digital audio on your DVD drive. The information is already digital (duh!) so its not like its any different than copying a file off a CD to your hard drive.

S/PDIF AFAIK is used to connect a Digital Sound signal to a Dolby Digital decoder(aka a reciever, some computer speakers also). If by S/PDIF you mean the wire from the back of the DVD drive to your sound card, that becomes an analog signal and may lead to some static/noise introduction into your sound.

Hope this helps

 

[MowSow]

Yes .. exactly .. I mean the cable used to connect S/PDIF outlet on the back of the CD/DVD to S/PDIF input on the sound card, all inside the PC case. You are saying that if I use a cable the signal is converted to analog right .. and the better way to go by that, is to enable digital audio, if I understand you well.

 

[Pariah]

No, it's not converted to analog, but there is no reason to use any audio cable if you are using Win2k/XP.

 

[Slammy1]

Interesting. My receiver does not recognize it as a digital output. A digital source like a DVD player sounds tremendously better. I'll play around some more, see what I can come up with.

 

[Auric]

The S/PDIF CD connector or even the S/PDIF option in a DVD decoder is not to be confused with digital output to a receiver which can be digital PCM (2 channel stereo or matrixed surround) or a digital bitstream such as DD/DTS which requires decoding.

There are usually two connectors on a drive: analog and digital. If the analog one is used then the drive's DAC is employed and in conjunction with the internal analog cable has the worst potential quality-wise. But when considering using the S/PDIF versus "on-the-fly DAE" via the Windows CD Digital option both should theoretically be the same quality but as I said the latter does use the PCI bus. However, if the system is not being used for anything particularly intensive then no difference in performance will be notable.

-
P.S. The Windows CD Digital feature should be considered a cost cutting measure that does the job but is not optimal. It's kinda akin to using AC97 sound and prolly one of the reasons it was employed as it enables mainboards with integrated audio to have functional CD sound without the adde cost of a S/PDIF connector.

 

[Slammy1]

I've tried several combos. I suppose the best I came up with was SPDIF with everything muted but the CD Digital. Problem is, it's not a true digital signal. I run a toslink out of a converter that Creative sells for the SBLive. It's the same set up as the Platinum. I think no matter what I buy, even if I got an audiophile board like the Terratec DMX 6fire 24/96 I'll have the same problem. It's like the toslink converter I have for my only receiver out (Tape, RCA output ), it's still a converted output to a digital cable. It's still not a true digital signal, and you can really hear the difference in playback.

 

[MowSow]

Thank you all for your participation .. this is very good info ... even though we have 2 contradicting opinions here .. one that says it is better to use an S/PDIF cable and the other says if you use it, it wont be a true digital signal !

 

[Auric]

I should have said "...without the added cost of any connector (including analog).

I remembered something about the Live!'s mixer and did a quick Google search and found discussions relating to the fact that it does not pass unadulterated digital I/O signals as you seem to be describing, but must convert via the DSP to a fixed frequency of 48 KHz which for CD audio means upsampling from 44.1 KHz. In any case there is a compromise there that probably does not exist on current generation cards.

 

[Slammy1]

Sorry, I did not mean to seem obtuse. I've tried it both ways (SPDIF both with and without the cable, but I only have the audio cable not the digital). My receiver would not recognize it as a digital source, but that could easily be my inter-connection between my sound card and stereo. I was wondering also, how do you get a true digital output to a toslink from my PC.

So an Audigy2 generation would do it? I guess I need to upgrade, again.

 

[Auric]

If you clarify the connections you are using it will be easier to help. What is this "audio cable not digital"?

 

[MowSow]

I think the real bottom line here is, that if you are using XP/2K, forget about the S/PDIF cable, enable the digital audio in windows and you're good to go.
It also looks like using an S/PDIG cable (internally from CD to Sound Card) instead of enabling digital audio wont give you a true digital signal.

 

[Slammy1]

I don't know about the last half of that statement. I have a riser card running out of my SBLive that allows for an optical cable to my receiver. No matter what I do (except maybe upgrade my card), I'll never get a true digital output to my receiver through the toslink. I think if you could get digital sound w/o the SPDIF, you could get it with one also.

I want to appeal to any card manufacturers out there. Make a card you can plug into your PC that works like a receiver. I just want all my components in one box so that I can program to my listening style. You have DVD, tuners, cds, even TiVo=VCR. It only makes sense to put an expensive card in to control it all to make it sound good.

 

[Woody419]

Originally posted by: Slammy1
No matter what I do (except maybe upgrade my card), I'll never get a true digital output to my receiver through the toslink.

The Onkyo UD-5 might do true digital because it doesn't use the sound card, it uses the USB bus and converts the signal to toslink.

 

[Slammy1]

Check this guy out:
http://www.audaud.com/audaud/SEP01/EQUIP/equip1SEP01.html

Simillar technolgy. I couldn't find anything else as far as a review, but it does look a bit promising. I just want to get rid of my receiver and use my PC with a couple of amplifiers and run regular speakers. I'd be set then, an upgradable receiver.

 

[Dug]

Why don't you get the M-Audio Revolution. With the right player you can get 44K from cd's.

The SPDIF out is just as good as the rest of them. (Except Creative, which is known to have problems with their digital out.)
The analog out is where the card shines and sounds better then using the DAC's in most modestly priced receivers.

 

[Auric]

The last thing you want to do is use the analog outputs on any card. Sure, some are better than others but the only way to get clean sound out of a PC is to get the signal away from the noisy innards in digital form -then it can safely be decoded and amplified as necessary.

Current generation cards do not have the fixed output of the Live! With the Audigy series for example, the PCM output sampling rate can be configured for 44.1, 48, or 96 KHz depending on the capability of the receiver.

Slammy1, are you having problems with audio other than from CD? What about DVD's and other sound files?

Perhaps the problem is with the Toslink. Have you tried coaxial?