On Mon, 14 Jan 2008 16:40:21 -0800 (PST) "Tom Enderlin" <tom@xxxxxxxxxxxx> wrote: > Hello, > I'm having a heck of time trying to figure this out and could really use > some help. > > Problem is that I'm able to use an old (crappy) labtec microphone, but the > two different headset microphones I tried, don't pick up a thing. > I've tried the headsets on another computer so I know the headset mics are > working. > > Hardware: ALC888 on a Shuttle XPC SN68SG2 using the snd-hda-intel driver > with a model=6stack-dig option. > All the other functions on the soundcard that I've tried are working. > > Software: Debian unstable. Tried both the debian packages (Alsa 1.0.15) > and compiling Alsa 1.0.15 from source. > > Tried moving all the mic and mic boost sliders in alsamixer to their max > settings and it still didn't record any audio, just background static. > > Also plugged the mic into the line-in jack on the back of the computer and > same thing: the old labtec mic worked but the newer headset mics didn't > > I'm totally at a loss here. The old microphone has a plain mono plug and > the headset has a stereo plug but I didn't think that should matter since > it's just a mono signal anyways. This is a new computer so it should > definitely be able to accept an off the shelf headset. > > Looked around and found various asoundrc files with input configurations, > but nothing has worked so far. Tried all the different snd-hda-intel > module options with no success. > > Any ideas at all would be appreciated. > Thanks. > Tom > Modern microphones use electret capsule + FET, the latter requires DC bias. Microphone input has the needed bias, line input doesn't. Your old Labtec microphone appears to be of dynamic type, so it doesn't need the DC bias. So, I guess, you have a problem of missing DC bias. Hopefully, ALSA experts will be able to relate this to ALSA - I do not have the expertise. It may also be a connection issue. You can check bias presence using a voltmeter if you have one and can extract the electret capsule from its (typically plastic) enclosure. Regards, Sergei. ------------------------------------------------------------------------- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
