Distortion Realtek ALC887

[fleamour]

Sounds can distort even when not amplified. Amplification worked well for years before recent PulseAudio update. The audio is Realtek ALC887 under an IntelG41 Chipset with GA-G41M-Combo main board;

Description: Ubuntu Bionic Beaver (development branch)
Release: 18.04

I am seeking to engage upstream for April LTS release. Windows have abandoned this esoteric hardware! Please Ubuntu! Keep a C2D user going!

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: pulseaudio 1:11.1-1ubuntu6
ProcVersionSignature: Ubuntu 4.13.0-32.35-generic 4.13.13
Uname: Linux 4.13.0-32-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia
ApportVersion: 2.20.8-0ubuntu10
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: fleamour 1049 F.... pulseaudio
 /dev/snd/controlC2: fleamour 1049 F.... pulseaudio
 /dev/snd/controlC0: fleamour 1049 F.... pulseaudio
CurrentDesktop: ubuntu:GNOME
Date: Mon Feb 19 13:54:33 2018
InstallationDate: Installed on 2018-02-19 (0 days ago)
InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Alpha amd64 (20180214)
ProcEnviron:
 LANGUAGE=en_GB:en
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
SourcePackage: pulseaudio
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 10/25/2012
dmi.bios.vendor: Award Software International, Inc.
dmi.bios.version: FB
dmi.board.name: G41M-Combo
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.board.version: x.x
dmi.chassis.type: 3
dmi.chassis.vendor: Gigabyte Technology Co., Ltd.
dmi.modalias: dmi:bvnAwardSoftwareInternational,Inc.:bvrFB:bd10/25/2012:svnGigabyteTechnologyCo.,Ltd.:pnG41M-Combo:pvr:rvnGigabyteTechnologyCo.,Ltd.:rnG41M-Combo:rvrx.x:cvnGigabyteTechnologyCo.,Ltd.:ct3:cvr:
dmi.product.name: G41M-Combo
dmi.sys.vendor: Gigabyte Technology Co., Ltd.

[Daniel van Vugt (vanvugt)]

This may be related to bug 1576420 with the same audio chip, but let's keep it separate for now...

Please tell us:
 * Does the bug exist in Ubuntu 17.10.1 if you live boot that?
 * Does the bug persist if you try installing older or newer kernels?
   http://kernel.ubuntu.com/~kernel-ppa/mainline/?C=N;O=D
 * If there is a kernel version that doesn't have the bug, are you able to narrow it down to find the kernel version that introduced it?

[fleamour (gtx-swift)]

Can confirm kernel makes no difference, also present in 17.10.1 & !6.04.3.

[fleamour (gtx-swift)]

Just by way of reference it is present in pretty much all modern distros.

[Daniel van Vugt (vanvugt)]

OK, please try some older (or much newer) kernels then:
http://kernel.ubuntu.com/~kernel-ppa/mainline/?C=N;O=D

[fleamour (gtx-swift)]

Can confirm kernel makes no difference.

[Daniel van Vugt (vanvugt)]

Please clarify exactly which kernel versions you have tested. It will help us to narrow down the problem.

[fleamour (gtx-swift)]

4.3.0
4.8.0
4.15.5

[Daniel van Vugt (vanvugt)]

Thanks.

I wonder if your system has Over-Amplification stuck on (even if the GUI says otherwise). Can you please look at Settings > Sound and make sure that:
  1. 'Over-Amplification' = OFF
  2. Lower the value of 'Output volume'

Can you find some combination of settings there that avoids the distortion?

[fleamour (gtx-swift)]

I have installed a PCI soundcard & it demonstrates same behavior. With amplification off, volume at 100%.

Turning sound down seems to cure, but obviously this is not loud enough!?!

[fleamour (gtx-swift)]

I installed Win 10 & still had audio glitching. This is not a software bug, got working in Mint 18.3 (will now test Ubuntu Beaver.) I have a 3.5mm audio splitter for double monitor set up. The upper one is toast (soundwise). Whether this is due to running full amplification not sure?!? What say you?

[Daniel van Vugt (vanvugt)]

If you experience the same sounding glitching in Win 10 then yes this sounds like a hardware problem. But you also said that "Amplification worked well for years before recent PulseAudio update", so I wonder if you can find any older Ubuntu release where it works still? Try live booting some of these:

  http://cdimages.ubuntu.com/releases/

Otherwise, try replacing your 3.5mm audio splitter and related cables. I was stunned in the past to discover that cheap/broken audio cables can severely distort sound, so it's probably worth trying other cables and connectors.

[fleamour (gtx-swift)]

Routed line out audio through a Monoprice component to VGA converter (PlayStation II anyone?) this box failed. Sorry to waste your valuable time.

[Daniel van Vugt (vanvugt)]

Was that the problem or the solution? :)

[fleamour (gtx-swift)]

Both! The Monoprice box of tricks caused distortion, but only in one monitor. I had completely forgotten my ever doing so. Never assume. Please delete this bug report.