@Gabriele, Dell ships it with this problem, my XPS shipped with Ubuntu 12.04 and it had this problem out of the box.
-- You received this bug notification because you are a member of Desktop Packages, which is subscribed to alsa-driver in Ubuntu. https://bugs.launchpad.net/bugs/1252733 Title: [XPS 12-9Q33, Realtek ALC668, Black Headphone Out, Left] Background noise or low volume Status in “alsa-driver” package in Ubuntu: Incomplete Bug description: When listening to sound on my laptop through headphones, there's a constant background hiss (which disappears only when all sound has been stopped for a few seconds. power saving I guess). I also need to turn the volume *way* down to 10% for the sound volume to be reasonable (it's way too loud otherwise). ProblemType: Bug DistroRelease: Ubuntu 13.10 Package: alsa-base 1.0.25+dfsg-0ubuntu4 ProcVersionSignature: Ubuntu 3.11.0-13.20-generic 3.11.6 Uname: Linux 3.11.0-13-generic x86_64 ApportVersion: 2.12.5-0ubuntu2.1 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC1: martijn 2130 F.... pulseaudio /dev/snd/pcmC1D0p: martijn 2130 F...m pulseaudio /dev/snd/controlC0: martijn 2130 F.... pulseaudio Date: Tue Nov 19 14:26:46 2013 EcryptfsInUse: Yes InstallationDate: Installed on 2013-11-13 (6 days ago) InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1) MarkForUpload: True PackageArchitecture: all SourcePackage: alsa-driver Symptom: audio Symptom_AlsaPlaybackTest: ALSA playback test through plughw:PCH successful Symptom_Card: Intern geluid - HDA Intel PCH Symptom_Jack: Black Headphone Out, Left Symptom_PulsePlaybackTest: PulseAudio playback test successful Symptom_Type: High background noise, or volume is too low Title: [XPS 12-9Q33, Realtek ALC668, Black Headphone Out, Left] Background noise or low volume UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 09/24/2013 dmi.bios.vendor: Dell Inc. dmi.bios.version: A03 dmi.board.name: XPS 12-9Q33 dmi.board.vendor: Dell Inc. dmi.board.version: A03 dmi.chassis.type: 8 dmi.chassis.vendor: Dell Inc. dmi.chassis.version: Not Specified dmi.modalias: dmi:bvnDellInc.:bvrA03:bd09/24/2013:svnDellInc.:pnXPS12-9Q33:pvrA03:rvnDellInc.:rnXPS12-9Q33:rvrA03:cvnDellInc.:ct8:cvrNotSpecified: dmi.product.name: XPS 12-9Q33 dmi.product.version: A03 dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/1252733/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp