I have great sound playback on my PC sound card for mp3, internet
radio, computer sounds, midis, etc. The sound from audio cds I put
into either of my cdrom drives, however, is lousy: scratchy, gurgly,
out of tune, etc. The cd drives work fine with a software cd and I can
burn from one to another accurately. The timing seems to be ok. The
sound card is an Avance ALS300. I am running Windows 98.

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Request for Question Clarification by mvguy-ga on 29 Oct 2002 05:31 PST

Does this happen with all audio CDs, or just certain ones?  Thanks.

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Request for Question Clarification by blader-ga on 29 Oct 2002 05:55 PST

Have you tried replacing the small thin wire that connects the CD
drive to your motherboard? It's not the big ribbon, which is the IDE
cable. A better quality one of the small wire, or a clean one, might
help a lot. CD audio in a CD drive isn't read through the IDE cable
like regular data, but rather it's sent through the smaller wire.

Let me know if this helps.

Just to take care of one simple possible cause, check your audio
volume properties and make sure the slider for "cd audio" is set to
maximum. A very low setting will likely cause the garbling you have
described.

Your problem is likely a consequence of the fact that the audio for a
cd-rom drive when playing audio cds comes through a different cable
than that of all other sounds. It connects to the back of the cd rom
drive inside of the computer via a 4 wire connector to the soundcard.
You may get poor results if this connector is loose, frayed, or low
quality.

First to troubleshoot this problem, I would try connecting headphones
to the front headphone jack of your cd rom drive, if it has one (most
do). If the sound quality is still poor, your particular cd rom drive
simply will not do a good job playing audio cds.

If the headphones sound good, you can trace the problem to one of a
few possibilities. Firstly, you should try replacing the audio cable
on the back of the cdrom drive that connects to the sound card in your
computer. Have a computer geek friend bring one over. Chances are they
have a few extras since most sound cards and cdrom drives come with
more than one.

If this does not solve the issue, there are three possibilities. 

Firstly, the cdrom drive may have a poor quality digital to analog
converter chip. However, if the headphones connected directly to the
cd drive sound good, this will not be the case.

The second possibility is that your sound card is of exceptionally low
quality. This is not likely since everything else sounds fine.

The third possibility is that your drive is doing digital audio
extraction to play back audio discs, but your drive is not very good
at doing digital audio extraction. As sparky noted in a comment below,
some versions of windows media player can enable or disable digital
audio extraction when playing back audio discs.

If your digital to analog converter is of low quality, I would
recommend enabling this option. If your DAC is good (as tested with
headphones) I would recommend disabling this option, since many cd rom
drives are not very good at doing digital audio extraction.

I hope this fully answers your question. If you find in
unsatisfactory, please request a clarification before rating the
answer.

CD-ROM drives have a built-in DAC (digital-analog converter) that
outputs analog sound to the pc sound card.  You could have one of the
best computers in the world and CD's will still sound like crap
because most CD-ROM drive manufacturers skimp on the DAC to lower
costs.

The cord you are referring to is a flat, 4-pin cable. This sends
analog audio to the sound card. Many drives (not all) also have a port
for a flat, 2-pin cable that sends the _digital_ audio stream to the
soundcard. Many CD player programs (for example, Windows Media Player
7+ if you are on a Windows platform) have an option to read digital
data ("digital audio extraction", i believe its called) from the CD.
If you select this option, the digital data will bypass the crappy
CD-ROM DAC and will be processed by your sound card which probably has
a better digital-to-analog converter. Note that this will increase the
processor load, sometimes a lot if you have an older machine.

Try enabling digital audio extraction on your CD playing program (try
windows media player if you are using a different program and cannot
find it).  If that doesn't work, check your CD-ROM to make sure that
it has the 2-pin digital audio port, and install the cable if it
doesn't already have one installed.

RE: Digital Audio Extraction.

This feature in some versions of Windows Media Player, other players,
and music ripping software (such as for burning custom CDs and for
making MP3s) doesn't normally rely on the digital audio plug on the
cd-rom drive. Digital Audio Extraction is done through the IDE cable.
What you're describing could be caused by poor DAE support, or a
system that isn't really fast enough for it. You could try disabling
DAE in media player, and see what happens. (Make sure you have the
regular cd audio cable connected first.)