[gobolinux-users] bemoaning the lack of sound

[Michael Homer]

On Nov 24, 2007 10:05 AM, Isaac Dupree <isaacdupree at charter.net> wrote:
> Isaac Dupree wrote:
> > Jonas Karlsson wrote:
> >> On Fri, 23 Nov 2007 19:15:39 +0100, Isaac Dupree <isaacdupree at charter.net> wrote:
> >>
> >>> and now testing the effect of headphones:
> >>>
> >>> when they're plugged in, no sound comes out of either the laptop's
> >>> built-in speakers nor the headphones.  Is there somewhere I need to set
> >>> plugged-in-speakers volume separately, or does it just not work yet? (or
> >>> something else)
> >>>
> >> I have no macbook but an intel sound card and the speakers and headphone
> >> jack is two different channels here. Use alsamixer (or kmix if you have
> >> kde) to see all channels and their levels.
> >
> > what are "channels"?  Are they the Front, Surround, Center, LFE, and
> > Side that I can see in alsamixer/kmix?
Yes. They probably continue well off to the right side too.
<snip>
> Wikipedia for IEC958 reveals it as a synonym for S/PDIF, but doesn't
> explain well enough what part of my hardware that is referring to or
> what it means
>
> but I'm slowly becoming educated about this! very good!
>
> What the heck??? I don't know what I did, but I just noticed that there
> is now a red glow coming out of the headphone jack in the computer, and
> the headphones have completely the expected behavior when plugging and
> unplugging!  Although I can't seem to find a way to mute the headphones.
>   Maybe having IEC958 unmuted for several minutes changed things (even
> though there is no effect if I mute it now for a few seconds)
>
> Any idea what's going on?
The names ALSA assigns to the different channels don't always
correspond to what they actually do, so it's worth fiddling with them
all until you track down which one does what. You probably changed
something you didn't realise was related. It's also (faintly) possible
there's another module powering the headphones that had to load
itself.

IEC958 may be an internal modem, if you have one, or "line out". If
you can't find a jack for it it may just be used internally - I have
far more channels than jacks, some of which seem to be connected into
each other.
-Michael