Dear experts,
 
I already tried to get some help via https://unix.stackexchange.com/questions/675121/sound-via-jack-is-totaly-distorted-pulseaudio-without-jack-works as well as in the german forum https://forum.ubuntuusers.de/topic/audio-ausgabe-bei-nutzung-von-jack-voellig-ueb/2/#post-9282854 unfortunatelly with no success although in the german forum many things were discussed.
So I decided to do a total fresh install of my Ubuntu Studio 21.10 but my problem still exists: The sound via JACK is totally distorted while the output with PulseAudio is ok. So now I would like to know, which posibilities there are to adjust JACKs output or if there is a bug and I only have to wait for a fix.

First of all, here is the information about my system (Ubuntu Studio 21.10) - in advance: The sound output is completely distorted as soon as Jack is activated (regardless of whether via JackDBus or JackD), although it was still working without any problems until a few days ago:

silvermoon@ubuntupc:~$ lsb_release -d
Description:    Ubuntu 21.10
silvermoon@ubuntupc:~$ uname -r
5.13.0-20-lowlatency
silvermoon@ubuntupc:~$ cat /proc/asound/cards
 0 [sofhdadsp      ]: sof-hda-dsp - sof-hda-dsp
                      LENOVO-20QF0027GE-ThinkPadX1Yoga4th
 1 [AUDIO          ]: USB-Audio - CONEXANT USB AUDIO
                      Conexant CONEXANT USB AUDIO at usb-0000:0a:00.0-2.1.1.2, full speed
silvermoon@ubuntupc:~$ aplay -l
**** Liste der Hardware-Geräte (PLAYBACK) ****
Karte 0: sofhdadsp [sof-hda-dsp], Gerät 0: HDA Analog (*) []
  Sub-Geräte: 1/1
  Sub-Gerät #0: subdevice #0
Karte 0: sofhdadsp [sof-hda-dsp], Gerät 1: HDA Digital (*) []
  Sub-Geräte: 1/1
  Sub-Gerät #0: subdevice #0
Karte 0: sofhdadsp [sof-hda-dsp], Gerät 3: HDMI1 (*) []
  Sub-Geräte: 1/1
  Sub-Gerät #0: subdevice #0
Karte 0: sofhdadsp [sof-hda-dsp], Gerät 4: HDMI2 (*) []
  Sub-Geräte: 1/1
  Sub-Gerät #0: subdevice #0
Karte 0: sofhdadsp [sof-hda-dsp], Gerät 5: HDMI3 (*) []
  Sub-Geräte: 1/1
  Sub-Gerät #0: subdevice #0
Karte 1: AUDIO [CONEXANT USB AUDIO], Gerät 0: USB Audio [USB Audio]
  Sub-Geräte: 1/1
  Sub-Gerät #0: subdevice #0
silvermoon@ubuntupc:~$ aplay /usr/share/sounds/alsa/Noise.wav
Wiedergabe: WAVE '/usr/share/sounds/alsa/Noise.wav' : Signed 16 bit Little Endian, Rate: 48000 Hz, mono
silvermoon@ubuntupc:~$ lspci -nnk | grep -iA2 audio
00:1f.3 Audio device [0403]: Intel Corporation Cannon Point-LP High Definition Audio Controller [8086:9dc8] (rev 11)
        Subsystem: Lenovo Cannon Point-LP High Definition Audio Controller [17aa:2292]
        Kernel driver in use: sof-audio-pci-intel-cnl
        Kernel modules: snd_hda_intel, snd_sof_pci_intel_cnl
00:1f.4 SMBus [0c05]: Intel Corporation Cannon Point-LP SMBus Controller [8086:9da3] (rev 11)
silvermoon@ubuntupc:~$ ps -C esd
    PID TTY          TIME CMD
silvermoon@ubuntupc:~$ ps -C arts
    PID TTY          TIME CMD
silvermoon@ubuntupc:~$ ps -C pulseaudio
    PID TTY          TIME CMD
   3654 ?        00:00:08 pulseaudio
silvermoon@ubuntupc:~$ grep "^audio" /etc/group | grep "$USER" | wc -l
1
silvermoon@ubuntupc:~$ dpkg -l | tr -s " " | grep " alsa-"
ii alsa-base 1.0.25+dfsg-0ubuntu7 all ALSA driver configuration files
ii alsa-tools 1.2.2-1 amd64 Console based ALSA utilities for specific hardware
ii alsa-tools-gui 1.2.2-1 amd64 GUI based ALSA utilities for specific hardware
ii alsa-topology-conf 1.2.5.1-2 all ALSA topology configuration files
ii alsa-ucm-conf 1.2.4-2ubuntu4 all ALSA Use Case Manager configuration files
ii alsa-utils 1.2.4-1ubuntu4 amd64 Utilities for configuring and using ALSA
silvermoon@ubuntupc:~$ lsmod | grep "snd"
snd_seq_dummy          16384  0
snd_usb_audio         299008  0
snd_usbmidi_lib        36864  1 snd_usb_audio
mc                     57344  5 videodev,snd_usb_audio,videobuf2_v4l2,uvcvideo,videobuf2_common
snd_ctl_led            24576  0
snd_soc_skl_hda_dsp    24576  5
snd_soc_intel_hda_dsp_common    20480  1 snd_soc_skl_hda_dsp
snd_soc_hdac_hdmi      36864  1 snd_soc_skl_hda_dsp
snd_hda_codec_hdmi     61440  1
snd_hda_codec_realtek   147456  1
snd_hda_codec_generic    81920  1 snd_hda_codec_realtek
snd_soc_dmic           16384  1
snd_sof_pci_intel_cnl    16384  0
snd_sof_intel_hda_common    98304  1 snd_sof_pci_intel_cnl
soundwire_intel        40960  1 snd_sof_intel_hda_common
snd_sof_intel_hda      20480  1 snd_sof_intel_hda_common
snd_sof_pci            20480  2 snd_sof_intel_hda_common,snd_sof_pci_intel_cnl
snd_sof_xtensa_dsp     16384  1 snd_sof_intel_hda_common
snd_sof               135168  2 snd_sof_pci,snd_sof_intel_hda_common
snd_soc_hdac_hda       24576  1 snd_sof_intel_hda_common
snd_hda_ext_core       32768  4 snd_sof_intel_hda_common,snd_soc_hdac_hdmi,snd_soc_hdac_hda,snd_sof_intel_hda
snd_soc_acpi_intel_match    49152  2 snd_sof_intel_hda_common,snd_sof_pci_intel_cnl
snd_soc_acpi           16384  2 snd_soc_acpi_intel_match,snd_sof_intel_hda_common
snd_soc_core          294912  7 soundwire_intel,snd_sof,snd_sof_intel_hda_common,snd_soc_hdac_hdmi,snd_soc_hdac_hda,snd_soc_dmic,snd_soc_skl_hda_dsp
snd_compress           28672  1 snd_soc_core
ac97_bus               16384  1 snd_soc_core
snd_pcm_dmaengine      16384  1 snd_soc_core
snd_hda_intel          53248  0
snd_intel_dspcfg       28672  2 snd_hda_intel,snd_sof_intel_hda_common
snd_intel_sdw_acpi     20480  2 snd_sof_intel_hda_common,snd_intel_dspcfg
snd_hda_codec         147456  7 snd_hda_codec_generic,snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec_realtek,snd_soc_intel_hda_dsp_common,snd_soc_hdac_hda,snd_soc_skl_hda_dsp
snd_hda_core           94208  11 snd_hda_codec_generic,snd_hda_codec_hdmi,snd_hda_intel,snd_hda_ext_core,snd_hda_codec,snd_hda_codec_realtek,snd_soc_intel_hda_dsp_common,snd_sof_intel_hda_common,snd_soc_hdac_hdmi,snd_soc_hdac_hda,snd_sof_intel_hda
snd_hwdep              16384  2 snd_usb_audio,snd_hda_codec
snd_pcm               122880  12 snd_hda_codec_hdmi,snd_hda_intel,snd_usb_audio,snd_hda_codec,soundwire_intel,snd_sof,snd_sof_intel_hda_common,snd_soc_hdac_hdmi,snd_compress,snd_soc_core,snd_hda_core,snd_pcm_dmaengine
snd_seq_midi           20480  0
snd_seq_midi_event     16384  1 snd_seq_midi
ledtrig_audio          16384  4 snd_ctl_led,snd_hda_codec_generic,snd_sof,thinkpad_acpi
snd_rawmidi            36864  2 snd_seq_midi,snd_usbmidi_lib
snd_seq                73728  7 snd_seq_midi,snd_seq_midi_event,snd_seq_dummy
snd_seq_device         16384  3 snd_seq,snd_seq_midi,snd_rawmidi
snd_timer              40960  2 snd_seq,snd_pcm
snd                    94208  31 snd_ctl_led,snd_hda_codec_generic,snd_seq,snd_seq_device,snd_hda_codec_hdmi,snd_hwdep,snd_hda_intel,snd_usb_audio,snd_usbmidi_lib,snd_hda_codec,snd_hda_codec_realtek,snd_timer,snd_soc_hdac_hdmi,snd_compress,thinkpad_acpi,snd_soc_core,snd_pcm,snd_soc_skl_hda_dsp,snd_rawmidi
soundcore              16384  2 snd_ctl_led,snd
silvermoon@ubuntupc:~$ head -n 3 /proc/asound/card0/codec#0
Codec: Realtek ALC285
Address: 0
AFG Function Id: 0x1 (unsol 1)
silvermoon@ubuntupc:~$ head -n 3 /proc/asound/card0/codec97#0/ac97#0-0
head: '/proc/asound/card0/codec97#0/ac97#0-0' kann nicht zum Lesen geöffnet werden: Datei oder Verzeichnis nicht gefunden
silvermoon@ubuntupc:~$ head -n 3 /proc/asound/card0/codec97#0/ac97#0-0+regs
head: '/proc/asound/card0/codec97#0/ac97#0-0+regs' kann nicht zum Lesen geöffnet werden: Datei oder Verzeichnis nicht gefunden
silvermoon@ubuntupc:~$ cat ~/.asoundrc
cat: /home/silvermoon/.asoundrc: Datei oder Verzeichnis nicht gefunden
silvermoon@ubuntupc:~$ cat ~/.asoundrc.asoundconf
cat: /home/silvermoon/.asoundrc.asoundconf: Datei oder Verzeichnis nicht gefunden
silvermoon@ubuntupc:~$ cat /etc/asound.conf
cat: /etc/asound.conf: Datei oder Verzeichnis nicht gefunden
silvermoon@ubuntupc:~$ cat .config/jack/conf.xml
<?xml version="1.0"?>
<!--
JACK settings, as persisted by D-Bus object.
You probably don't want to edit this because
it will be overwritten next time jackdbus saves.
-->
<!-- Tue Oct 26 11:43:30 2021 -->
<jack>
 <engine>
  <option name="driver">alsa</option>
  <option name="realtime">true</option>
  <option name="verbose">true</option>
  <option name="sync">false</option>
  <option name="self-connect-mode">a</option>
 </engine>
 <drivers>
  <driver name="loopback">
  </driver>
  <driver name="netone">
  </driver>
  <driver name="alsa">
   <option name="device">hw:0</option>
   <option name="capture">hw:0</option>
   <option name="playback">hw:0</option>
   <option name="rate">48000</option>
   <option name="period">1008</option>
   <option name="nperiods">2</option>
   <option name="duplex">true</option>
   <option name="dither">n</option>
   <option name="midi-driver">raw</option>
  </driver>
  <driver name="dummy">
  </driver>
  <driver name="firewire">
  </driver>
  <driver name="net">
  </driver>
  <driver name="alsarawmidi">
  </driver>
  <driver name="proxy">
  </driver>
 </drivers>
 <internals>
  <internal name="netmanager">
  </internal>
  <internal name="audioadapter">
  </internal>
  <internal name="profiler">
  </internal>
  <internal name="netadapter">
  </internal>
 </internals>
</jack>
silvermoon@ubuntupc:~$

Note: In relation to the problem, it makes no difference whether frames / periods in Jack is set to this strange value of 1008 or 128 or 512 or 1024 or ... I've already tried a lot here.

Setting without Jack: Jack is inactive, LoudnessLevel (LL) 100%, aplay Front_Center.wav, output normal via pulse audio without any distortion or clipping,

Settings below are with active jack

  • Setting 1: LL=100%, PulseAudioJackSink (PAJS)=100%, aplay via PulseAudioJackSink->system-playback, output is totaly distorted
  • Setting 2: LL=100%, PAJS=20% (shortly before distortion), aplay output not nice but understandable ;-)
  • Setting 3: LL=20%, Output MuseScore via Jack->system-playback, whereby the volume control in MuseScore is set to -79.5db (normal at approx. -25db): already distorted
  • Setting 4: same setting as in #3 but LL=60%: output totaly distorted. Same effect if volume control in MuseScore is set to more than approx. -78db. Not only the output of PAJS and MuseScore, everything is distorted, especially if the soundsource using jack couldn't be leveled down itself.

Without knowing what I might have changed and where there could changes be made: A short time ago (in any case with 21.04, but I also mean under 21.10) everything worked without any problems. Do you have any ideas where to change appropriate settings? I have already done the following:

  • ALSA module reinstallation
  • Complete reset of alsa and trying different levels of the alsamixer settings, although what is strange (for me) here: I don't have a PCM controller
  • tried JackD instead of JackDBus
  • reset of pulseaudio configuration
  • total stop of pulseaudio while running Jack
  • fresh installation of Ubuntu Studio 21.10

Thanks in advance for any hint!