Sound issue

[Bill Freeman]

bscott at ntisys.com writes:
< A discription of the two possible path from the bits on the CD to the
speaker jack: audio electronic signals; DAE, bits making their way through
software to the D to A converter(s) in the sound card.>

	Yes, and I'm not positive which path actually works when it works.

	I have some additional information. Soundcore and the driver
are modules, and are not configured to load at boot time(*).  The CD
app., gnome-cd, starts when the audio CD is inserted, but it does not
cause these modules to load.  Other apps that use sound, like "play"
or "iagno", manage to invoke the loading of these modules, and once
that has happened, CD music comes out of the speakers just fine.

[ * Thanks, Fred, for suggesting looking at this.  Fred sent a reply
off list.  I'm not going to post his E-mail address without his
explicit permission, and I'm not going to guess that his last name is
one of the fields of his domain.]

	Also, I was apparently mistaken: the mixer (volume control is
the name of the RH menu item) does make things start working.  My problems
despite using must have been with a previous hardware configuration.  (I
have a recenty acquired DVD+/-RW drive that replaced my old drives.)

 >   Most likely cause of difference behaviors: When the sound works, the
 > software is using DAE, and when it does not, it is using analog playback.  
 > This would also explain why your headphones do work.

	Actually, the headphones are always going to work no matter what
else is wrong, since that jack is part of the drive itself.

	The sliders on the far right of the mixer app, labeled "CD",
and those on the far left, labeled "vol", are the only ones that
affect the volume of interest.  Specifically, the sliders labeled
"synth" and "pcm" have no effect.  Does that tell me whether the path
is DAE or analog?

 >   Most likely cause of the analog failures: You have a connection problem
 > between the drive and the sound card.  It could be the cable simply was
 > never installed, or is loose, or whatever.

	It's installed.  I've checked this extensively.  Right now the path
goes through a TV/FM tuner card, but these problems are longstanding.  I'll
fool with a direct connection again, however.

	Actually, I've just done an experiment that I think proves
that I'm using the analog path.  If I unplug one of the cables from
the TV/FM card, Peggy Lee's voice goes away.

 >   Other possible causes of the analog failures:
 > 
 >   It could be your sound card is fried or otherwise defective.  It could
 > also be the mixer is not being programmed by the OS correctly.  You do
 > indicate the mic has never worked.  The mic input and the CD input are
 > basically two channels of the same thing, so I suspect they may be related.

	And this is still possible, though it is far fetched to say
that it accounts for the failure of modules to load for gnome-cd.  The
sound is built into the mother board (ASUS A7V266-E), and the mic jack
is on one of those mother board risers to present to the back panel,
so there's no cabling issue there (though I suppose that there could
be a jumper issue - I wish it were possible to get schematics for
these things - it's not like the rival company can't read the chip set
specs for themselves).  Certainly the mic doesn't go through the CD
drive audio cable.

 >   I usually tell people to also check their mixer settings, but you say
 > you've done that already.  If you set the mixer, exit the mixer program, and
 > then go back in, are the settings retained?  If not, that is a sign of
 > trouble.

	Settings are, indeed, retained.

	There are plenty of work arounds open to me at this point (for
gnome-cd, not for the mic jack).  For example, preloading the driver
at boot time.

	I'll spend a little time, though, seeing if I can figure out
what gnome-cd doesn't do that leaves the modules unloaded.  It
apparently doesn't hold a reference to the driver either: lsmod shows
a 0 usage count.  Perhaps gnome-cd just assumes, erroneously for this
sound chip, that this path is unmuted at reset, and that therefore it
makes no reference to the driver.  And that makes it interesting that
the driver, cmpci, doesn't seem to eventually unload, since it is
marked autoclean.

	If I figure anything out, I'll let the list know.

							Bill