Digital noise with Ubuntu

What other apps and distros do you use to round out your studio?

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Re: Distorted sound with Ubuntu

Post by j_e_f_f_g »

Mister Mint wrote:

the noise now appeared with AV Linux + JACK...

there's no noise with AVL + JACK (only with AVL + Pulseaudio)...

AVL + JACK I only get sound in one channel / speaker now

There's something amiss in your trouble-shooting. You're getting conflicting results. Offhand, I'm guessing that you're not isolating one component at a time, applying one change, and observing the result. It seems like you're randomly applying changes, hoping that something will suddenly work, without carefully observing the full result of each change.

The net result is that you're introducing new problems with your changes, and not noticing what change has produced what behavior. You may want to check youtube for videos on trouble-shooting. It's supposed to be "a process of elimination", but what you're doing seems to be producing even more confusing results.

a PCI express bus, but how to check if that's the cause

If that's the problem, I would first try moving the audio card to a different slot. Sometimes, two slots may share an irq, and two devices in those slots will interfere with each others' operation. I would also get into the bios and disable everything that isn't necessary to boot your computer -- ethernet/serial/usb/bluetooth ports, motherboard audio, etc. If this fixes the problem, you need to turn things back on, one device at a time, in order to discover which piece of hardware is causing the problem. And when you find the culprit, see what resources it's using (ie irqs, ports) and check if your bios allows you to reassign those resources.

Remember: Process of elimination.

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Re: Distorted sound with Ubuntu

Post by Mister Mint »

Ok thanks, and sorry for my late reply.

Well, in general I do try to apply one change at a time, but maybe at some point I have done something unconsciencely that has either started or stopped the noise. Maybe a change done in a different context that, for some reason not obvious to me, affected the sound. Okay, just speculating. Apart from the possibility of some hardware damage that makes the noise random, I have no idea why at one time AV Linux + JACK also had noise.

I have moved the card to another slot now, but the noise remains. So now I'll disable some things in BIOS and see what happens. There's a lot in there I don't know the meaning of, though, so I'd better read a little about those things first :)

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Re: Distorted sound with Ubuntu

Post by Mister Mint »

I've now disabled everything in BIOS I don't use, but the noise is still there :(

As for AV Linux, I've logged in there several times now since last, and every time Pulseaudio has the same noise as on Ubuntu Studio, while JACK has no noise.

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Re: Distorted sound with Ubuntu

Post by asbak »

There could be all kinds of reasons, often it's to do with the hardware itself or other components in your house which causes problems.

For example:

Powerline / Ethernet adapters used in a home can be faulty or low quality and that noise comes in via Ethernet.
There could be issues with house earthing and ground loops.
There could be issues with PC power supply which introduces noise.
There could be BIOS settings (overclocking, overvolting etc) which causes power supply to cause noises.
It could perhaps be something to do with shared IRQs.
The audio device itself may have problems etc.

The first things I would try is to set BIOS / UEFI to factory defaults, to unplug Ethernet and to switch to a different soundcard.

Some Focal / 20.04 audio packages and resources https://midistudio.groups.io/g/linuxaudio
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Re: Distorted sound with Ubuntu

Post by j_e_f_f_g »

asbak, the fact that he hears this noise using PulseAudio, but not with Jack on the same hardware, seems to indicate it isn't a hardware problem. If he really has isolated the problem to pulseaudio, then it's either a pulseaudio bug or setting that needs to be adjusted. Since AV LInux doesn't use Pipewire, I think the culprit is pulseaudio itself.

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Re: Distorted sound with Ubuntu

Post by asbak »

Ahh, that is strange, thanks Jeff.

j_e_f_f_g wrote: Mon Mar 27, 2023 12:38 am

asbak, the fact that he hears this noise using PulseAudio, but not with Jack on the same hardware, seems to indicate it isn't a hardware problem. If he really has isolated the problem to pulseaudio, then it's either a pulseaudio bug or setting that needs to be adjusted. Since AV LInux doesn't use Pipewire, I think the culprit is pulseaudio itself.

Some Focal / 20.04 audio packages and resources https://midistudio.groups.io/g/linuxaudio
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Re: Distorted sound with Ubuntu

Post by merlyn »

Mister Mint wrote: Mon Feb 20, 2023 10:21 pm

... I use Ubuntu Studio 20.04, and have done so for a year or so without any problems, but then I moved my hard-drive and soundcard to another computer, and after this I get a very distorted, crackling sound.

It's not 'distortion' as such. Distortion has a specific definition -- distortion is correlated with the signal. So when we have a distorted electric guitar we can still hear the pitch. The distortion is adding in upper harmonics, which is the definition of distortion. Distortion is usually produced in an analogue system going wrong (being overloaded). I think what you have here is digital audio going wrong, which produces 'xruns' -- buffer under-runs, which are heard as clicks, and a stream of them sound like crackling. If you could provide a sound sample of the crackling, that may help.

PS. When I moved the hard-drive and soundcard to the other computer, I also installed another graphics card, but I guess that has no impack on the sound.

So you're right, the graphics card is not in the audio path. But the GPU driver can stop the audio buffer being filled, which causes xruns. Is it an Nvidia card? There can be issues with the Nvidia drivers available.

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Re: Distorted sound with Ubuntu

Post by j_e_f_f_g »

merlyn wrote:

the GPU driver can stop the audio buffer being filled, which causes xruns.

Um, no. If it were the graphics driver, then the problem would appear with JACK and ALSA too, and not just with PulseAudio.

This is basic trouble-shooting.

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Re: Distorted sound with Ubuntu

Post by Mister Mint »

asbak wrote: Sun Mar 26, 2023 9:58 pm

Powerline / Ethernet adapters used in a home can be faulty or low quality and that noise comes in via Ethernet.
There could be issues with house earthing and ground loops.
There could be issues with PC power supply which introduces noise.
There could be BIOS settings (overclocking, overvolting etc) which causes power supply to cause noises.
It could perhaps be something to do with shared IRQs.
The audio device itself may have problems etc.

The first things I would try is to set BIOS / UEFI to factory defaults, to unplug Ethernet and to switch to a different soundcard.

Thanks for the suggestions, but as jeefg says, it seems like it's not a hardware problem. Anyways, I disconnected the Internet cable just to try, but it made no difference. About house earthing, I have no wall outlet with that nearby, so would need a long cable, but if ground loops are the cause of the noise, then I wonder why there was no noise with the old computer. It used the same outlet.

I've just set BIOS to factory defaults now, but the noise survived it :( Before that I also tried to update BIOS following this guide https://www.cyberciti.biz/faq/update-le ... stick-pen/, but when I rebooted and got the Startup Interrupt Menu, there was no F12 ("choose a temperary startup device") option, like shown here https://youtu.be/2CGrawsd_TA?t=201 in the video, and at the attached picture below.

Don't know if it's because I before that made a general update of firmware, following this guide https://itsfoss.com/update-firmware-ubuntu/, with this output:

Code: Select all

thomas@thomas-P5Q-SE:~$ sudo apt update && sudo apt upgrade -y
[sudo] adgangskode for thomas:
Havde:1 http://dk.archive.ubuntu.com/ubuntu focal InRelease                    
Havde:2 http://dk.archive.ubuntu.com/ubuntu focal-updates InRelease
Havde:3 http://dk.archive.ubuntu.com/ubuntu focal-backports InRelease
Havde:4 http://ppa.launchpad.net/pipewire-debian/pipewire-upstream/ubuntu focal InRelease Havde:5 http://security.ubuntu.com/ubuntu focal-security InRelease
Indlæser pakkelisterne... Færdig Opbygger afhængighedstræ
Læser tilstandsoplysninger... Færdig 13 pakker kan opgraderes. Kør »apt list --upgradable« for at se dem. Indlæser pakkelisterne... Færdig Opbygger afhængighedstræ
Læser tilstandsoplysninger... Færdig Beregner opgraderingen... Færdig Følgende pakker blev installeret automatisk, og behøves ikke længere: gir1.2-goa-1.0 libxmlb1 Brug »sudo apt autoremove« til at fjerne dem. Get more security updates through Ubuntu Pro with 'esm-apps' enabled: libgraphicsmagick-q16-3 libavformat58 libmagick++-6.q16-8 libavfilter7 libimage-magick-perl ffmpeg liburiparser1 libmagickcore-6.q16-6-extra libimage-magick-q16-perl imagemagick libswresample3 libgegl-0.4-0 libzmq5 python2.7-minimal libhdf5-103 libmagickwand-6.q16-6 libgegl-common libpython2.7 python2.7 libmediainfo0v5 libpostproc55 imagemagick-6.q16 libavcodec-extra libjs-jquery-ui libavutil56 libavdevice58 libswscale5 libopenexr24 libsdl2-2.0-0 libmagickcore-6.q16-6 libpython2.7-minimal libgraphicsmagick++-q16-12 libhdf5-openmpi-103 libavcodec-extra58 libdcmtk14 libpython2.7-stdlib libavresample4 imagemagick-6-common Learn more about Ubuntu Pro at https://ubuntu.com/pro Følgende pakker vil blive opgraderet: bind9-dnsutils bind9-host bind9-libs gnome-software gnome-software-common gnome-software-plugin-snap libsnmp-base libsnmp35 python3-software-properties software-properties-common software-properties-gtk update-notifier update-notifier-common 13 opgraderes, 0 nyinstalleres, 0 afinstalleres og 0 opgraderes ikke. 9.326 kB skal hentes fra arkiverne. Efter denne handling, vil 15,4 kB yderligere diskplads være brugt. Henter:1 http://dk.archive.ubuntu.com/ubuntu focal-updates/main amd64 update-notifier amd64 3.192.30.17 [56,4 kB] Henter:2 http://dk.archive.ubuntu.com/ubuntu focal-updates/main amd64 update-notifier-common all 3.192.30.17 [173 kB] Henter:3 http://dk.archive.ubuntu.com/ubuntu focal-updates/main amd64 bind9-dnsutils amd64 1:9.16.1-0ubuntu2.14 [134 kB] Henter:4 http://dk.archive.ubuntu.com/ubuntu focal-updates/main amd64 bind9-libs amd64 1:9.16.1-0ubuntu2.14 [1.109 kB] Henter:5 http://dk.archive.ubuntu.com/ubuntu focal-updates/main amd64 bind9-host amd64 1:9.16.1-0ubuntu2.14 [43,0 kB] Henter:6 http://dk.archive.ubuntu.com/ubuntu focal-updates/main amd64 gnome-software-plugin-snap amd64 3.36.1-0ubuntu0.20.04.1 [73,0 kB] Henter:7 http://dk.archive.ubuntu.com/ubuntu focal-updates/main amd64 gnome-software amd64 3.36.1-0ubuntu0.20.04.1 [893 kB] Henter:8 http://dk.archive.ubuntu.com/ubuntu focal-updates/main amd64 gnome-software-common all 3.36.1-0ubuntu0.20.04.1 [5.559 kB] Henter:9 http://dk.archive.ubuntu.com/ubuntu focal-updates/main amd64 software-properties-common all 0.99.9.11 [10,4 kB] Henter:10 http://dk.archive.ubuntu.com/ubuntu focal-updates/main amd64 software-properties-gtk all 0.99.9.11 [69,1 kB] Henter:11 http://dk.archive.ubuntu.com/ubuntu focal-updates/main amd64 python3-software-properties all 0.99.9.11 [21,6 kB] Henter:12 http://dk.archive.ubuntu.com/ubuntu focal-updates/main amd64 libsnmp-base all 5.8+dfsg-2ubuntu2.7 [206 kB] Henter:13 http://dk.archive.ubuntu.com/ubuntu focal-updates/main amd64 libsnmp35 amd64 5.8+dfsg-2ubuntu2.7 [978 kB] Hentede 9.326 kB på 3s (3.157 kB/s) (Læser database ... 481142 filer og kataloger installeret i øjeblikket.) Gør klar til at udpakke .../00-update-notifier_3.192.30.17_amd64.deb ... Udpakker update-notifier (3.192.30.17) over (3.192.30.16) ... Gør klar til at udpakke .../01-update-notifier-common_3.192.30.17_all.deb ... Udpakker update-notifier-common (3.192.30.17) over (3.192.30.16) ... Gør klar til at udpakke .../02-bind9-dnsutils_1%3a9.16.1-0ubuntu2.14_amd64.deb . .. Udpakker bind9-dnsutils (1:9.16.1-0ubuntu2.14) over (1:9.16.1-0ubuntu2.12) ... Gør klar til at udpakke .../03-bind9-libs_1%3a9.16.1-0ubuntu2.14_amd64.deb ... Udpakker bind9-libs:amd64 (1:9.16.1-0ubuntu2.14) over (1:9.16.1-0ubuntu2.12) ... Gør klar til at udpakke .../04-bind9-host_1%3a9.16.1-0ubuntu2.14_amd64.deb ... Udpakker bind9-host (1:9.16.1-0ubuntu2.14) over (1:9.16.1-0ubuntu2.12) ... Gør klar til at udpakke .../05-gnome-software-plugin-snap_3.36.1-0ubuntu0.20.04. 1_amd64.deb ... Udpakker gnome-software-plugin-snap (3.36.1-0ubuntu0.20.04.1) over (3.36.1-0ubun tu0.20.04.0) ... Gør klar til at udpakke .../06-gnome-software_3.36.1-0ubuntu0.20.04.1_amd64.deb ... Udpakker gnome-software (3.36.1-0ubuntu0.20.04.1) over (3.36.1-0ubuntu0.20.04.0) ... Gør klar til at udpakke .../07-gnome-software-common_3.36.1-0ubuntu0.20.04.1_all .deb ... Udpakker gnome-software-common (3.36.1-0ubuntu0.20.04.1) over (3.36.1-0ubuntu0.2 0.04.0) ... Gør klar til at udpakke .../08-software-properties-common_0.99.9.11_all.deb ... Udpakker software-properties-common (0.99.9.11) over (0.99.9.8) ... Gør klar til at udpakke .../09-software-properties-gtk_0.99.9.11_all.deb ... Udpakker software-properties-gtk (0.99.9.11) over (0.99.9.8) ... Gør klar til at udpakke .../10-python3-software-properties_0.99.9.11_all.deb ... Udpakker python3-software-properties (0.99.9.11) over (0.99.9.8) ... Gør klar til at udpakke .../11-libsnmp-base_5.8+dfsg-2ubuntu2.7_all.deb ... Udpakker libsnmp-base (5.8+dfsg-2ubuntu2.7) over (5.8+dfsg-2ubuntu2.6) ... Gør klar til at udpakke .../12-libsnmp35_5.8+dfsg-2ubuntu2.7_amd64.deb ... Udpakker libsnmp35:amd64 (5.8+dfsg-2ubuntu2.7) over (5.8+dfsg-2ubuntu2.6) ... Sætter bind9-libs:amd64 (1:9.16.1-0ubuntu2.14) op ... Sætter update-notifier-common (3.192.30.17) op ... Sætter libsnmp-base (5.8+dfsg-2ubuntu2.7) op ... Sætter gnome-software-common (3.36.1-0ubuntu0.20.04.1) op ... Sætter python3-software-properties (0.99.9.11) op ... Sætter update-notifier (3.192.30.17) op ... Sætter bind9-host (1:9.16.1-0ubuntu2.14) op ... Sætter libsnmp35:amd64 (5.8+dfsg-2ubuntu2.7) op ... Sætter software-properties-common (0.99.9.11) op ... Sætter bind9-dnsutils (1:9.16.1-0ubuntu2.14) op ... Sætter software-properties-gtk (0.99.9.11) op ... Behandler udløsere for desktop-file-utils (0.24-1ubuntu3) ... Behandler udløsere for mime-support (3.64ubuntu1) ... Behandler udløsere for hicolor-icon-theme (0.17-2) ... Behandler udløsere for libglib2.0-0:amd64 (2.64.6-1~ubuntu20.04.4) ... Behandler udløsere for libc-bin (2.31-0ubuntu9.9) ... Behandler udløsere for man-db (2.9.1-1) ... Behandler udløsere for dbus (1.12.16-2ubuntu2.3) ... Behandler udløsere for shared-mime-info (1.15-1) ... Sætter gnome-software (3.36.1-0ubuntu0.20.04.1) op ... Sætter gnome-software-plugin-snap (3.36.1-0ubuntu0.20.04.1) op ... thomas@thomas-P5Q-SE:~$ sudo service fwupd start thomas@thomas-P5Q-SE:~$ sudo fwupdmgr refresh WARNING: UEFI firmware can not be updated in legacy BIOS mode See https://github.com/fwupd/fwupd/wiki/PluginFlag:legacy-bios for more information. Updating lvfs Downloading… [***************************************] Successfully downloaded new metadata: 0 local devices supported thomas@thomas-P5Q-SE:~$ sudo fwupdmgr update WARNING: UEFI firmware can not be updated in legacy BIOS mode See https://github.com/fwupd/fwupd/wiki/PluginFlag:legacy-bios for more information. Devices with no available firmware updates: • Hitachi HDS721616PLA380 • ST3320620AS No updatable devices
j_e_f_f_g wrote: Mon Mar 27, 2023 12:38 am

If he really has isolated the problem to pulseaudio, then it's either a pulseaudio bug or setting that needs to be adjusted. Since AV LInux doesn't use Pipewire, I think the culprit is pulseaudio itself.

I replaced Pulseaudio with Pipewire on Ubuntu Studio, but that didn't kill the noise. Oh, I have forgotten to give you an important info: The 'Ubuntu Studio Controls' that used to be under Menu -> Settings is no longer there. I can't remember exactly when it disappeared, but it puzzles me :? I'll attach a picture of its Audio Setup, taken from the internet, so you can see it yourself.

Btw, the noise is only present when some sound is played (regardless of the player), it's not a constant background noise.

merlyn wrote: Mon Mar 27, 2023 2:54 pm

It's not 'distortion' as such. Distortion has a specific definition -- distortion is correlated with the signal. So when we have a distorted electric guitar we can still hear the pitch. The distortion is adding in upper harmonics, which is the definition of distortion. Distortion is usually produced in an analogue system going wrong (being overloaded). I think what you have here is digital audio going wrong, which produces 'xruns' -- buffer under-runs, which are heard as clicks, and a stream of them sound like crackling. If you could provide a sound sample of the crackling, that may help.

PS. When I moved the hard-drive and soundcard to the other computer, I also installed another graphics card, but I guess that has no impack on the sound.

So you're right, the graphics card is not in the audio path. But the GPU driver can stop the audio buffer being filled, which causes xruns. Is it an Nvidia card? There can be issues with the Nvidia drivers available.

Thanks for the explanation. Good to get the definitions right! I tried to record a sample with the mic that's connected to my computer, using Audacity, but strangely, when the recording is going on, there is no noise! My system is playing a game on me :shock: Apart from Ardour, which I haven't got access to, the only other recording app is OBS Studio, but the same happens here, except that here simply having the app running stops the noise. If for instance I play a sound file with say VLC, and OBS Studio is running in the background at the same time, then there is no noise! Well, naturally there's a logical explanation, but to me it's a digital jungle.

Anyways, instead I took two samples using a phone. The cracle is more audible in quiet music, like the first sample, and I think some frequencies give more noise than others.

https://www.reverbnation.com/klingband/ ... rtistMusic

https://www.reverbnation.com/klingband/ ... rtistMusic

Yes indeed, it IS a Nvidia card (Quadro FX 580). I've had it suspected too, or rather its driver as you say, but as jeefg points out, why doesn't the problem appear with JACK on AV Linux then? Unless this Nvidia driver somehow conflicts with both Pulseaudio and Pipewire?

A probably irrelevant, but strange note: Before I installed the Nvidia card, I had first moved my original GPU (a Radeon) from the old computer to the new one, but there its cooling fan apparantly didn't work, because after 10 minutes or so I got a black screen, and when I turned the computer on next time and immediately ran Psensor, I saw how the temperature quickly raised to 100 C or so. Strange (to me) because the card had worked perfectly on the old computer, and I didn't damage it during the movement. But again, probably irrelevant.

Congratz for getting through this long post :)

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Re: Digital noise with Ubuntu

Post by j_e_f_f_g »

Oh, that's not underruns. It sounds like phase shifting. It's like you have your stereo output being doubled, with one set slightly delayed. Offhand, I suspect a routing problem. Specifically, something is "echoing" your stereo output, with a slight delay. It strongly suggests a software problem. Turn off any "software monitoring", and unnecessary "bridges" (ie, get rid of anything that routes PulseAudio through JACK. Set PulseAudio to go directly to ALSA).

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Re: Digital noise with Ubuntu

Post by merlyn »

It certainly is strange. If I were to put this into loose sound engineering language I would describe it as narrow band noise gated by the signal. How exactly that could happen, I'm not sure. Strange enough for me to load the quieter track into Sonic Visualiser.

Image

The vertical lines are attack points. The notes themselves are the red bit down at the bottom; the yellow horizontal bars are harmonics. The plot more or less stops at roughly 13kHz. That is half the sample rate of your phone I would think. The problem -- the noise -- is above the gap at 8kHz. It seems everything above 8kHz is noise. If anyone has a clue WTF is going on here, please post.

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Re: Digital noise with Ubuntu

Post by merlyn »

If there was a problem at 50Hz or 60Hz we would immediately think that that was the mains frequency. So what is operating at 8kHz? 8kHz is the frequency that USB 2.0 sends audio packets at. It sends 8 packets per millisecond giving a frequency of 8kHz.

Although there is evidence that the problem is due to configuration, the sound sample sounds like hardware going wrong. As far as I understand it, digital audio doesn't go wrong in this way.

Do you get the same noise when using headphones that are known to work?

Do you get the same noise when using different outputs on the interface?

Do you get the same noise when using a different USB port on the computer?

Do you get the same noise when using a different USB cable that is known to be good?

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Re: Digital noise with Ubuntu

Post by asbak »

Yes strange problem Mr Mint. I've had issues in the past with BIOS settings (voltage, clockspeed etc) and the power supply conspiring to create weird "pinging" sounds in the audio chain but your case is obviously something different.

I'm out of ideas aside from reinstalling the audio servers and / or starting over with default audio configuration files.

Is there an .asoundrc file?
Were changes made to pulseaudio client & server configs?
Does the situation improve when using a different sound card?
Is there maybe weird going on with inconsistent sample rate settings somewhere (applications, sound servers or whatever) or sample rate conversion being done somewhere?

On my box almost everything is set to 48kHz

Some Focal / 20.04 audio packages and resources https://midistudio.groups.io/g/linuxaudio
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Re: Digital noise with Ubuntu

Post by asbak »

Mr Mint said: Thanks for the explanation. Good to get the definitions right! I tried to record a sample with the mic that's connected to my computer, using Audacity, but strangely, when the recording is going on, there is no noise!

Which reminds me, Audacity uses Port Audio. I'm not a programmer and already having enough problems not to get horribly confused with how the different audio components interact with one another, but aren't you effectively removing Pulse Audio from the chain here when recording with Audacity? Ie, Port Audio + ALSA?

If that's the case (somebody else know?) then that may explain why Audacity is working for you, because there's no Pulseaudio involved?

So confusing.....

Some Focal / 20.04 audio packages and resources https://midistudio.groups.io/g/linuxaudio
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Re: Digital noise with Ubuntu

Post by Mister Mint »

j_e_f_f_g wrote: Thu Mar 30, 2023 7:32 am

Turn off any "software monitoring", and unnecessary "bridges" (ie, get rid of anything that routes PulseAudio through JACK. Set PulseAudio to go directly to ALSA).

Sorry, but where do I do that?

Wow, interesting to see the noise. A lot nicer than hearing it!

"Do you get the same noise when using headphones that are known to work?"

Yes. And also when I play a CD from the computer drive, but not when from a CD player.

"Do you get the same noise when using different outputs on the interface?"

Sorry, what interface do you mean?

"Do you get the same noise when using a different USB port on the computer?"

Yes. The only USB devices are the mouse and keyboard. I have moved them to different ports, and also tried disconnecting them from the computer, both one at a time, and both at the same time while playing sound, but in every case the noise remains.

"Do you get the same noise when using a different USB cable that is known to be good?"

The mouse and keyboard have their own cables, so I guess I'd have to try another mouse and /or keyboard (equipped with good cables)?

"Is there an .asoundrc file?"

I can't find any, and I haven't created one, so I don't think so.

"Were changes made to pulseaudio client & server configs?"

I don't remember, but since I replaced Pulseaudio with Pipewire, I thought pulseaudio played no role anymore? Well, there's probably a lot about these clients and servers I don't understand right.

"Does the situation improve when using a different sound card?"

Presently I haven't got another, but maybe I should get one. Worth a try. It worked fine on the old computer, though, and afaik I didn't damage it during the movement.

"Is there maybe weird going on with inconsistent sample rate settings somewhere (applications, sound servers or whatever) or sample rate conversion being done somewhere?"

In the Qjackctl settings I have tried shifting between 44.1 and 48 kHz, but it made no difference. I'm not sure where to set it in Pipewire?

"aren't you effectively removing Pulse Audio from the chain here when recording with Audacity? Ie, Port Audio + ALSA?"

I guess so, but to be honest I haven't got a clue :?

Audacity.png
Audacity.png (118.22 KiB) Viewed 1594 times

Probably nothing to do with the noise, but something is apparently wrong with my Ubuntu Studio installation, because every time I start / restart it, I get a pop up message saying "Problem with system program found. Do you wish to report the problem now?" I have reported it, but of course that doesn't solve any problem here and now. I'm not sure, but I think it popped up after having tried to update BIOS. But since the same noise also appears on AV Linux using Pulseaudio, I believe this problem is not the cause.

Problem med systemprogram.png
Problem med systemprogram.png (14.61 KiB) Viewed 1594 times

Maybe I should upgrade from US 20.04 to 22.04. I haven't because 22.04 was criticized a lot. It had many drawbacks and bugs, but perhaps updates have improved it since then.

Btw, it's not only Audacity and OBS Studio that stops the noise, also having "Volume Control" running does it (no matter its settings). And I guess more apps will do the same.

Volume Control.png
Volume Control.png (18.71 KiB) Viewed 1594 times

So actually, just having one of those running all the time in the background would in a way solve the problem, but of course that wouldn't be an ideal sollution.

I could imagine the source of the problem is some combination of wrong software settings and perhaps incompatible, dated hardware. Maybe I should just bite the bullit and replace it all :cry:

Last edited by Mister Mint on Sun Apr 02, 2023 7:39 pm, edited 1 time in total.
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