I fixed the glitches with "load-module module-udev-detect tsched=0" and "load-module module-udev-detect tsched=0"
like I read on https://wiki.ubuntu.com/Audio/PositionReporting. I had to apply both fixes to solve the problem.
ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: alsa-base 1.0.25+dfsg-0ubuntu4
ProcVersionSignature: Ubuntu 3.8.0-19.29-generic 3.8.8
Uname: Linux 3.8.0-19-generic x86_64
ApportVersion: 2.9.2-0ubuntu8
Architecture: amd64
Date: Sat Apr 20 18:52:06 2013
InstallationDate: Installed on 2012-10-23 (178 days ago)
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Release amd64 (20121017.5)
MarkForUpload: True
PackageArchitecture: all
SourcePackage: alsa-driver
Symptom: audio
Symptom_AlsaPlaybackTest: ALSA playback test through plughw:PCH successful
Symptom_Card: Audio interno - HDA Intel PCH
Symptom_Jack: Speaker, Internal
Symptom_PulsePlaybackTest: PulseAudio playback test successful
Symptom_Type: Underruns, dropouts, or "crackling" sound
Title: [K53SD, Realtek ALC269VB, Speaker, Internal] Underruns, dropouts or crackling sound
UpgradeStatus: Upgraded to raring on 2013-03-06 (44 days ago)
dmi.bios.date: 11/02/2011
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: K53SD.202
dmi.board.asset.tag: ATN12345678901234567
dmi.board.name: K53SD
dmi.board.vendor: ASUSTeK Computer Inc.
dmi.board.version: 1.0
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: ASUSTeK Computer Inc.
dmi.chassis.version: 1.0
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrK53SD.202:bd11/02/2011:svnASUSTeKComputerInc.:pnK53SD:pvr1.0:rvnASUSTeKComputerInc.:rnK53SD:rvr1.0:cvnASUSTeKComputerInc.:ct10:cvr1.0:
dmi.product.name: K53SD
dmi.product.version: 1.0
dmi.sys.vendor: ASUSTeK Computer Inc.
This release of Ubuntu is no longer receiving maintenance updates. If this is still an issue on a maintained version of Ubuntu please let us know.