Sound Card Questions

I recently bought a 'Sound Blaster Live 5.1 Digital' card for my 2nd PC and
find that the CD Audio socket for connecting the CDRW drive Audio Out to the
Sound card is not present.
Since then I've been told by the supplier that it's not required as the CDRW
Drive transfers digital sound to the sound card via the IDE cable.
So to check this I went to my first PC (where I have a Sound Blaster Live
Value Card on a WinME PC) and disconnected both the CD Audio and the SP-DIF
cables from the CDRW drive to the SB Live and although I can play and hear a
music CD still, it appears that I'm not getting digital sound. I say this
because if I select 'Digital Output Only' in the Mixer the sound immediately
cuts off. However, this is not simply a result of disconnecting the above
mentioned cables because this also occured with both cables connected. So
the question(s) is as follows:
A. What is the preferred method of connecting a CDRW drive to the sound
card? Via Audio and/or SP-DIF cables between the CDRW drive and the sound
card or via the IDE cable?
B. Is it possible to get digital sound from a Sound Blaster Live card and/or
a Sound Blaster Live 5.1 Digital and if so how?
C: If it is the case that the IDE cable transfers digital sound to the sound
card why are CDRW drives and the SB Live card fitted with CD Audio and
SP-DIF sockets?



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I recently bought a 'Sound Blaster Live 5.1 Digital' card for my 2nd PC
and
find that the CD Audio socket for connecting the CDRW drive Audio Out to
the
Sound card is not present.

That is very curious, since those cards have always had that connector in
the past. If there are any other sockets (live cards have traditionally had
TAD and AUX analog audio inputs as well in addition to CD), you can just as
well use one of those instead.

Since then I've been told by the supplier that it's not required as the
CDRW
Drive transfers digital sound to the sound card via the IDE cable.

Well, it sort of IS required actually.

This feature will most likely only work in applications that actually
support that feature (such as Microsoft's Media Player version 8 or
greater), and provided your CDROM drive is capable of digitally extracting
audio that way. Also, some CDROM drives are far from perfect when reading
audio CDs digitally and introduce what is known as 'jitter', which reveals
itself as annoying snaps and pops in the sound.

Games for instance, or other media player software will still play CD audio
the old-fashioned way.

although I can play and hear a
music CD still, it appears that I'm not getting digital sound. I say this
because if I select 'Digital Output Only' in the Mixer the sound
immediately
cuts off.

Why would you select "digital output only" in the mixer? That checkbox only
applies to the sound outputs on the back of the soundcard itself, so unless
you have a SPDIF digital-capable receiver hooked up to your soundblaster and
switch its input over to digital, you will naturally not get any sound when
your PC's analog audio output is disabled with that checkbox. This feature
has nothing to do with digital output from a CDROM drive.

A. What is the preferred method of connecting a CDRW drive to the sound
card? Via Audio and/or SP-DIF cables between the CDRW drive and the sound
card or via the IDE cable?

No straight answer possible. "It depends", sort of. If your CDROM has SPDIF
out, you should use it, as that bypasses the traditionally VERY sub-standard
digital-to-analog converter in the CDROM itself. When you use SPDIF out from
your CDROM, you can mute the analog CD audio input in the sound mixer,
though be aware that applications (such as games, etc) that allow you to
adjust CD audio volume will not understand you're using digital SPDIF, so
the slider will have no effect.

If you're using an application that can do digital audio extraction and send
the data across the IDE bus, and the CDROM unit can extract audio reliably,
then that could be an useful feature. You'll have to decide for yourself
which method you prefer. There might well be minute differences in sound
quality, and IDE digital extraction might have some (very minor) impact on
system performance too. With SPDIF connection between the soundcard and
CDROM, the CD is simply spinning and data goes straight through the cable to
the soundcard and then out to speakers. With the IDE method, data has to be
buffered in main RAM, the CPU has to oversee the process, send commands
periodically to both the CDROM and soundcard to make them keep fetching
data. A sudden strain on the CPU or your IDE interface might potentially
cause sound break-up, though I haven't actually experienced that myself.

B. Is it possible to get digital sound from a Sound Blaster Live card
and/or
a Sound Blaster Live 5.1 Digital and if so how?

If it has a SPDIF output on the rear bracket (or on the livedrive break-out
box that attaches to the expansion connector on the card), then you'll have
a pure digital output that can either be used to play straight stereo sound,
or using a DVD software player, output multichannel Dolby Digital or DTS
audio. As mentioned before, you need a digital-capable receiver to decode
the signal and convert it back to analog of course, and multiple speakers to
take care of more channels than standard stereo...

C: If it is the case that the IDE cable transfers digital sound to the
sound
card why are CDRW drives and the SB Live card fitted with CD Audio and
SP-DIF sockets?

Legacy reasons.

I've gone over most of them in my post already, additional reasons are that
optical drives are used in computers other than PCs too, and they might not
use the IDE extraction method.

"Lenny" wrote in message
...
This feature will most likely only work in applications that actually
support that feature (such as Microsoft's Media Player version 8 or
greater), and provided your CDROM drive is capable of digitally extracting
audio that way. Also, some CDROM drives are far from perfect when reading
audio CDs digitally and introduce what is known as 'jitter', which reveals
itself as annoying snaps and pops in the sound.

Thank you for your advice.
Well I tried it all ways now. CDRW to CD IN, CDRW dig out to SP-DIF IN &
just IDE
Sound quality seems much the same except that IDE only does cause jitter and
does break up the sound if I load any 'heavy' software while it's playing
All music software I use works in either configuration
I'm gonna send the 5.1 card back since the extra socket could be useful.

One other question. Does the insertion of a CD IN or SP-DIF cable switch off
the IDE route. How would I know which is active?
Once again, thanks for your help

Thank you for your advice.

You're welcome. Glad to help!

I'm gonna send the 5.1 card back since the extra socket could be useful.

This may perhaps not be of help to you, but the Audigy series (the basic
version of the cards, the one lacking the internal/external break-out boxes)
all have a full battery of analog audio inputs, including cd-in. I have the
Audigy2 ZS, and while it is pricyer than the other Live/Audigy cards, it is
also a very, very nice soundcard.

One other question. Does the insertion of a CD IN or SP-DIF cable switch
off
the IDE route.

No, they are just dumb inputs. You could potentially have one optical drive
connected to cd-in and another to the spdif-in, for example.

How would I know which is active?

If you use a program that actively allows you to select (such as MS Media
Player), it's the program that decides. The IDE method isn't seen as playing
the music disc by the optical drive, so it won't send any data to the analog
audio or spdif outputs.

If you choose to not use the IDE method, you just mute the input you do NOT
want to use in the audio mixer. You may also need to go into the device
manager, then open the optical drives sub-heading, then double-click each
drive you have installed. In one of the tabs in the new window you'll find a
checkbox that says something along the lines of "activate digital audio for
this device". Uncheck it if neccessary, that way you'll only get CD audio
the regular way.

Once again, thanks for your help

No problem.

Was just perusing another article and came upon something that might
help you. "The audio signal from the drive playing a music CD passes
through your sound card via a small cable, which may have only one
connector for audio input. To play audio CDs from either drive you'll
need a Y-cable (available at most consumer electronic stores) that
splits a single line into two, as a telephone-line splitter does, so
that you can connect both drives' sound cables to the sound card. Or
you can get a sound card with two ports." Taken from "How to Solve the
Weirdest PC Mysteries",Steve Bass and Kirk Steers, June2002 issue of
PC World Magazine
"D Allen" wrote in message ...
"Lenny" wrote in message
...
This feature will most likely only work in applications that actually
support that feature (such as Microsoft's Media Player version 8 or
greater), and provided your CDROM drive is capable of digitally extracting
audio that way. Also, some CDROM drives are far from perfect when reading
audio CDs digitally and introduce what is known as 'jitter', which reveals
itself as annoying snaps and pops in the sound.

Thank you for your advice.
Well I tried it all ways now. CDRW to CD IN, CDRW dig out to SP-DIF IN &
just IDE
Sound quality seems much the same except that IDE only does cause jitter and
does break up the sound if I load any 'heavy' software while it's playing
All music software I use works in either configuration
I'm gonna send the 5.1 card back since the extra socket could be useful.

One other question. Does the insertion of a CD IN or SP-DIF cable switch off
the IDE route. How would I know which is active?
Once again, thanks for your help