i have seen this on 14.04 & 14.10 Running Google Music from FireFox to Arcam Irdac.
It ran fine for around 12 minutes then after a track change it turned into cracking due to high volume sounded like it was going to crack my speakers. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to pulseaudio in Ubuntu. https://bugs.launchpad.net/bugs/1414402 Title: [USB-Audio - USB Audio DAC, playback] Ocassional crackling, rarer light hissing in one of the two channels Status in pulseaudio package in Ubuntu: Confirmed Bug description: I see this output from "pulseaudio," but nothing is logged when the sound crackles: W: [pulseaudio] sink.c: Default and alternate sample rates are the same. W: [pulseaudio] source.c: Default and alternate sample rates are the same. E: [alsa-sink-Intel ICH] alsa-sink.c: ALSA woke us up to write new data to the device, but there was actually nothing to write! E: [alsa-sink-Intel ICH] alsa-sink.c: Most likely this is a bug in the ALSA driver 'snd_intel8x0'. Please report this issue to the ALSA developers. E: [alsa-sink-Intel ICH] alsa-sink.c: We were woken up with POLLOUT set -- however a subsequent snd_pcm_avail() returned 0 or another value < min_avail. W: [alsa-sink-USB Audio] protocol-native.c: Failed to push data into queue This is all with default settings. Disabling the Pulse Audio scheduler doesn't help. The audio output should be flawless. It's practically impossible to figure out ALSA, even with the Internet. ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: pulseaudio 1:4.0-0ubuntu11 ProcVersionSignature: Ubuntu 3.13.0-37.64-generic 3.13.11.7 Uname: Linux 3.13.0-37-generic i686 NonfreeKernelModules: nvidia ApportVersion: 2.14.1-0ubuntu3.6 Architecture: i386 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: westonlast 3706 F.... pulseaudio westonlast 6055 F.... pulseaudio /dev/snd/controlC1: westonlast 3706 F.... pulseaudio westonlast 6055 F.... pulseaudio CurrentDesktop: Unity Date: Sun Jan 25 01:33:09 2015 InstallationDate: Installed on 2014-10-03 (114 days ago) InstallationMedia: Ubuntu 14.04.1 LTS "Trusty Tahr" - Release i386 (20140722.2) SourcePackage: pulseaudio Symptom: audio Symptom_AlsaPlaybackTest: ALSA playback test through plughw:DAC successful Symptom_Card: USB Audio DAC - USB Audio DAC Symptom_PulsePlaybackTest: PulseAudio playback test failed Symptom_Type: Underruns, dropouts, or "crackling" sound Title: [USB-Audio - USB Audio DAC, playback] Underruns, dropouts or crackling sound UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 04/03/2006 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 1204 dmi.board.asset.tag: alienware dmi.board.name: A8N32-SLI-Deluxe dmi.board.vendor: ASUSTeK Computer INC. dmi.board.version: Rev 1.xx dmi.chassis.asset.tag: Asset-1234567890 dmi.chassis.type: 3 dmi.chassis.vendor: alienware dmi.chassis.version: alienware dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1204:bd04/03/2006:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKComputerINC.:rnA8N32-SLI-Deluxe:rvrRev1.xx:cvnalienware:ct3:cvralienware: dmi.product.name: System Product Name dmi.product.version: System Version dmi.sys.vendor: System manufacturer modified.conffile..etc.pulse.default.pa: [modified] mtime.conffile..etc.pulse.default.pa: 2015-01-24T22:30:13.991660 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/1414402/+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