[Samsung Notebook 7 Pro, Realtek ALC256, headphone jack] Headphone sound is faint and distorted (but works fine in Windows)

Thanks for the bug report. This kind of sound problem is usually a bad connection between the audio socket and the headphones. Usually it is because of the differing standards in common use:

https://www.cablechick.com.au/blog/understanding-trrs-and-audio-jacks/

and/or just slight imperfections in how the connectors come into contact.

So please try some different headphones as a test. Please also try using any kind of adapter or other audio cable you have to see if it gets a better connection and improves the sound.

First of all, thanks for replying!

I did this already when I noticed the problem a couple days ago with my main pair and with some gaming gear to no avail. But, since you asked, I did it again with all the wired headphones I could find around, even some crappy cellphone headphones and the results are the same: extremely low sound and heavily distorted. I even tried with a P2 cable extender and the problem remains, I'm 100% sure that it isn't my headphones.

Also tried all those headphones and cable extender on Windows and everything works fine.

(all of them work perfectly on other devices running Android, on my PS4 through the DualShock jack and with my smart TV)

It's important to point out that I know of at least another user of this machine facing the same issue. He posted about HDMI output problems - that I can confirm on my laptop as well - on the Linux Mint (link down below) forums and I got in touch with him, so I don't think that this has something to do with the physical connection, specially since the distortion goes away for a bit if you delete the /.config/pulse directory.

I didn't file a bug report about the HDMI output because it isn't as important as the headphone output for my workflow.
https://forums.linuxmint.com/viewtopic.php?f=49&t=303303

I'm assuming when you say Windows works fine that you mean Windows on this same laptop...?

Yes, I'm on a dual-boot setup.

I think it's also worth mentioning that I've tried Manjaro and experienced the same problems.

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1850702

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

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Tried the apport-collect command, but it fails because it says it didn't found linux and alsa-driver packages.

Just to give more insight about this, I just tried a live USB with 18.04.03 and the results are similar: the sound is extremely low, but with no distortion whatsoever.

I don't know if my problem is related specifically to the Realtek AC256 codec. In any case, it seems FreeBSD folk fixed a while back the same issue: no headphone output through some patches related to this codec on some Dell models.

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=219350
https://github.com/trueos/trueos/pull/279
https://reviews.freebsd.org/D19017

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

Please test latest mainline kernel:
https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.4/

Updated the kernel to the 5.4 as suggested and it didn't make any difference: sound through headphone jack still is low and heavily distorted.

That was the correct kernel to try for December 2019, but now 5.5 is released so please try that :)

https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.5.2/

Just updated to 5.5.2 and got the same results

Thanks. Please also run 'uname -a' each time to verify the new kernel is running.

I sure did, running both new kernels didn't fix it.

An update: testing some more, I can confirm that there were improvements on volume, now it is definetely louder: if it weren't the buzzing effect on the sound, I could say it was fixed. On the other hand, the louder it gets the more noticeable the distortion became.

Oh, and I noticed that both of the new kernels are throwing some acpi related errors on boot and on shutdown. I didn't really look that much about them online - so I don't really know if they are serious or not - but as far as I can tell, everything else that was working on the laptop remains so.

I redownloaded and reinstalled the 5.5.2 and saw some errors related to Nvidia drivers on install as well. But as I'm runnnig it with integrated graphics, I can't say if there's problem awaiting me as soon as I jump to the dedicated graphics.

Please test kernel parameter "snd_hda_intel.model=inv-dmic".

Pain is over!

https://www.linux.org/threads/samsung-notebook-7-force-headphone-jack-and-keyboard-lighting-issues.27304/#post-87920

Hey, I own a Notebook 7 and was having the same problem with the headphone jack (sound very low and distorted). I managed to solve based on the solution at https://bbs.archlinux.org/viewtopic.php?pid=1898849#p1898849. Basicaly, I created the files at /lib/firmware/alc256-sound-patch.fw with the content

[codec]
0x10ec0256 0x144dc824 0

[verb]
0x1a 0x707 0x05

and at /etc/modprobe.d/alc256-sound-patch.conf with content

options snd-hda-intel patch=alc256-sound-patch.fw

Reboot, and you should have sound working even after reboots.

The values may differ in the codec line, but it's all explained at the link I put. You may test before applying the patch with the command
sudo hda-verb /dev/snd/hwC0D0 0x1a 0x707 0x05
(the sound must be playing and headphones connected, but it will no persist after reboot)

Is it confirmed that this bug is fixed in newer Kernels? I am running 5.4.0.66 and have this problem in a Samsung laptop as well.

Thank you.

The command

sudo hda-verb /dev/snd/hwC0D0 0x1a 0x707 0x05

works for me, but the patch proposed (I added the files), do not seem to be working after reboots. Currently I have to run the command above everytime I reboot.