wofgdkncxojef@... wrote:

will check the attachments later, but evidently amixer and amixer_c0 differ,
which means either you capture wrong output, or pulse is not your default
mixer.

I found this for you perhaps you double check

> Realtek ALC888

I have here linux-4.15.8 but you can look in whatever release you have

ALC88x/898/1150
======================
acer-aspire-4930g
    Acer Aspire 4930G/5930G/6530G/6930G/7730G
acer-aspire-8930g
    Acer Aspire 8330G/6935G
acer-aspire
    Acer Aspire others
inv-dmic
    Inverted internal mic workaround
no-primary-hp
    VAIO Z/VGC-LN51JGB workaround (for fixed speaker DAC)
dual-codecs
    ALC1220 dual codecs for Gaming mobos

[linux-4.15.8/Documentation/sound/hd-audio/models.rst]


anyway, try a different model option if you have such a problem.
Some other models may match better and give you more matching
functionality.  If none of the available models works, send a bug
report.  See the bug report section for details.

[linux-4.15.8/Documentation/sound/hd-audio/notes.rst]


this is (was) done via adding in /etc/modprobe.d/alsa-base.conf

options snd-hda-intel model=MODEL

sudo alsa force-reload 

or reboot after