[Ubuntu 12.04 32bit, Realtek ALC662 rev1, Pink Mic, Front] Sound is distorted

[Skif]

Ubuntu 12.04; linux-kernel 3.2.0-27; alsa driver ver. 1.0.24 i have some problem with my HDA Intel ALC662 rev1. When i unmuting front mic in alsamixer, noise appear in my speakers in rear panel, but anyone devices is not plugged in in front panel. Besides in pulseaudio-control panel in hardware properties my device set to analog stereo duplex, and i can't set it to analog stereo output beacouse it's always set back to stereo duplex.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: alsa-base 1.0.25+dfsg-0ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-27.43-generic-pae 3.2.21
Uname: Linux 3.2.0-27-generic-pae i686
NonfreeKernelModules: nvidia
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
ApportVersion: 2.0.1-0ubuntu11
Architecture: i386
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: skif 1850 F.... pulseaudio
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xdbef8000 irq 43'
   Mixer name : 'Realtek ALC662 rev1'
   Components : 'HDA:10ec0662,10438290,00100101'
   Controls : 38
   Simple ctrls : 20
CurrentDmesg: [ 24.064008] eth0: no IPv6 routers present
Date: Thu Jul 19 23:01:21 2012
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release i386 (20120423)
PackageArchitecture: all
SourcePackage: alsa-driver
Symptom: audio
Symptom_AlsaRecordingTest: ALSA recording test through plughw:Intel successful
Symptom_Card: Встроенное аудио - HDA Intel
Symptom_Jack: Pink Mic, Front
Symptom_PulseAudioRecordingTest: PulseAudio recording test through plughw:Intel successful
Symptom_Type: Digital clip or distortion, or "overdriven" sound
Title: [System Product Name, Realtek ALC662 rev1, Pink Mic, Front] Sound is distorted
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 01/07/2008
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 0404
dmi.board.asset.tag: To Be Filled By O.E.M.
dmi.board.name: P5G-MX
dmi.board.vendor: ASUSTeK Computer INC.
dmi.board.version: Rev x.xx
dmi.chassis.asset.tag: Asset-1234567890
dmi.chassis.type: 3
dmi.chassis.vendor: ASUSTek Computer INC.
dmi.chassis.version: Rev 1.xx
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr0404:bd01/07/2008:svnSystemmanufacturer:pnSystemProductName:pvrRev1.xx:rvnASUSTeKComputerINC.:rnP5G-MX:rvrRevx.xx:cvnASUSTekComputerINC.:ct3:cvrRev1.xx:
dmi.product.name: System Product Name
dmi.product.version: Rev 1.xx
dmi.sys.vendor: System manufacturer

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Raymond (superquad-vortex2)]

that is normal as you tron front mic playback switch and rear mic playback switch

Simple mixer control 'Front Mic',0
  Capabilities: pvolume pswitch penum
  Playback channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Mono:
  Front Left: Playback 31 [100%] [12.00dB] [on]
  Front Right: Playback 31 [100%] [12.00dB] [on]
Simple mixer control 'Front Mic Boost',0
  Capabilities: volume penum
  Playback channels: Front Left - Front Right
  Capture channels: Front Left - Front Right
  Limits: 0 - 3
  Front Left: 3 [100%] [30.00dB]
  Front Right: 3 [100%] [30.00dB]

[Launchpad Janitor (janitor)]

[Expired for pulseaudio (Ubuntu) because there has been no activity for 60 days.]