* Takashi Iwai <tiwai@xxxxxxx> [2007-10-31 11:47]: > At Mon, 29 Oct 2007 01:44:34 +0100, > Peter Plessas wrote: > > > > Dear List, > > > > having a Compaq Presario notebook in front of me, running Debian testing > > and a 2.6.18-4-686 kernel, i have a strange DC offset when trying to > > record audio via the mic/line input. As the audacity level meters > > suggest, it resides at -30dBFS. > > Audio comes through and gets recorded though, but the offset severely > > limits the headroom of course. > > The sensitivity of the line/mic input seems to be quite high, although i > > have the mic boost setting turned off of course. > > Setting the module option ac97_quirk=yes did not help either. > > Can it be that a soundcard of this strange behavior is manufactured, or > > is it an alsa/driver issue? I really don't want to install another M$ > > operating system to check if it works there, so any help is deeply > > appreciated. > > > > lspci lists the device as: > > 00:07.5 Multimedia audio controller: VIA Technologies, Inc. VT82C686 > > AC97 Audio Controller (rev 20) > > AFAIK, there is no specific issue about recording (capture) in via82xx > driver. So, it should be likely about AC97 codec, if it really > matters. > > The first thing is to show your mixer setting. Run "alsactl -f > somefile store" and the file contains the mixer status. You can show > here together with the contents of /proc/asound/card0/codec97#0/* > files. > > Also, trying another apps, such as, arecord is a good test. In > addition, it's worth to upgrade the ALSA driver version, too. > > > Takashio I just checked with a windows installation, and there the DC is appearing too. Also with arecord it is the same. So it might really be the hardware... argh! alsactl -f file: http://mona.mur.at/alsactl.txt cat /proc/asound/card0/codec97#0/: http://mona.mur.at/ac97_0-0.txt http://mona.mur.at/ac97_0-0+regs.txt I might need to get an external soundcard it seems. I wonder how hard it is to find a working usb stereo card. Thanks for the help! Peter _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
