[G752VY, Realtek ALC668, Black Line Out, Right] Background whir or pipes

[Wenzel]

Problem: There is humming and high-frequency whistling over the entire volume of the line-out headphones and speakers. This problem does not exist under the WIN10 only under Ubuntu 18.04

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: alsa-base 1.0.25+dfsg-0ubuntu5
ProcVersionSignature: Ubuntu 4.15.0-32.35-generic 4.15.18
Uname: Linux 4.15.0-32-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.9-0ubuntu7.2
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: frank 1851 F.... pulseaudio
 /dev/snd/controlC0: frank 1851 F.... pulseaudio
CurrentDesktop: ubuntu:GNOME
Date: Sun Aug 19 11:58:46 2018
InstallationDate: Installed on 2018-05-13 (98 days ago)
InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: alsa-driver
Symptom: audio
Symptom_AlsaPlaybackTest: ALSA playback test through plughw:PCH successful
Symptom_Card: Eingebautes Tongerät - HDA Intel PCH
Symptom_Jack: Black Line Out, Right
Symptom_PulsePlaybackTest: PulseAudio playback test successful
Symptom_Type: High background noise, or volume is too low
Title: [G752VY, Realtek ALC668, Black Line Out, Right] Background noise or low volume
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 06/29/2017
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: G752VY.304
dmi.board.asset.tag: ATN12345678901234567
dmi.board.name: G752VY
dmi.board.vendor: ASUSTeK COMPUTER INC.
dmi.board.version: 1.0
dmi.chassis.asset.tag: ATN12345678901234567
dmi.chassis.type: 10
dmi.chassis.vendor: ASUSTeK COMPUTER INC.
dmi.chassis.version: 1.0
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrG752VY.304:bd06/29/2017:svnASUSTeKCOMPUTERINC.:pnG752VY:pvr1.0:rvnASUSTeKCOMPUTERINC.:rnG752VY:rvr1.0:cvnASUSTeKCOMPUTERINC.:ct10:cvr1.0:
dmi.product.family: G
dmi.product.name: G752VY
dmi.product.version: 1.0
dmi.sys.vendor: ASUSTeK COMPUTER INC.