QJack problem after installing ALSA Mixer

[Atitudes]

Hi everyone!

First of all I would like to say that I am an Ubuntu enthusiast, my knowledge is basic as a simple user but I do like to experiment and try different functionalities and software.

Overview:
As a musician, I use QJack along with Guitarix and other programs such as Audacity, Ardour, Hydrogen, Reason... Until yesterday everything was working fine although I had the "brilliant" idea to try to get sound output from my speakers and headphone set at the same time. After some forum and google searches, it seemed that ALSA Mixer could be the solution but I was not able to achieve my goal (If anyone could help me with this issue I would appreciate!). I sometimes use my sound card for audio input (Line-in or Mic entry), and other times an USB device when I do not have a Mixing table at hand. After having installed ALSA Mixer, my idea of having 2 sound output at the same time did not work, thus I removed it from my system.

The problem:
What happens now is that I have a sort of "by-pass" using my Line-in and QJack has no effect on it -> I disconnect everything and the sound continues to play. Even with all the connections properly connected it makes no input at all. I also noted that even without QJack, my line-in plays sound but do not make any input to any software, e.g. Audacity (Using ALSA and configuring the entry to Line-in).

Note:
None of the above applies when I use my mic entry as everything works as it should, the problem only affects the Line-in.


Everything happened after I installed and un-installed ALSA Mixer so I presume it to be the source of the problem, unfortunately with my poor knowledge I am unable to revert the situation now. I searched forums and googled about this but I was not able to find a solution to my problem. I really appreciate some help about this as I really want to make it work again as it was!!!

Thank you very much in advance.

[Atitudes]

Any tips please?

[stevem531]

Hello Atitudes

I too use audio related software (on Ubuntu 12.04) including Audacity and QjackCtl with Jack.

I am not an expert, but I offer the following comments in the hope that it might help resolve your problem.

If I have understood the symptoms correctly, having had ALSA Mixer (package gnome-alsamixer) installed and then removed there now appears to be a permanent through-route between the Line-in and the sound card output (speakers/headphones).

Something that you might consider is whether your sound card hardware has any provision for through-routing of input signals to the outputs ?

For examining and changing sound card settings I use the program alsamixer, part of the the alsa-utils package, which is run from a terminal window but has a basic (ncurses) graphical iinterface.

The alsa-utils package includes other command line utilities that are useful for debugging the ALSA configuration, but they need to be used with care and I do not have sufficient experience to advise you further - you will need help from one of the 'real experts'. With a bit of luck one will turn up very soon !!

Regards

Stephen

[Atitudes]

Hi stevem531, thank you very much for your feed back!

If I have understood the symptoms correctly, having had ALSA Mixer (package gnome-alsamixer) installed and then removed there now appears to be a permanent through-route between the Line-in and the sound card output (speakers/headphones).

You understood it all, that's completely what happened! And my goal is to revert the situation since it would be lovely to use mic and Line-in inputs at the same time again (of course, without the referred through-route in my Line-in...).

Something that you might consider is whether your sound card hardware has any provision for through-routing of input signals to the outputs ?

For examining and changing sound card settings I use the program alsamixer, part of the the alsa-utils package, which is run from a terminal window but has a basic (ncurses) graphical iinterface.

The alsa-utils package includes other command line utilities that are useful for debugging the ALSA configuration, but they need to be used with care and I do not have sufficient experience to advise you further - you will need help from one of the 'real experts'. With a bit of luck one will turn up very soon !!

My sound card is on-board and it doesn't seems I can do anything to configure input/output signals "outside" of ALSA resources (If it is possible, please guide me I would really appreciate, maybe it is the source of this problem).

I did installed ALSA mixer but didn't changed anything in its configuration as I only tried some volume options aiming for having two simultaneous outputs (speakers and headphones). Some posts stated that if I could enable the "Headphone Jack Sense" option it would work but the latter did not appeared in the ALSA mixer utility. Furthermore, I did ran ALSA mixer you referred (the ncurses graphical interface) but everything seems ok, perhaps I am missing something in the middle... I really don't know and thus requiring help!

I will keep on trying different solutions, step by step but I agree with you, I think I really need some "real experts'" help at the moment.

Once again, thank you for your feedback!
Cheers.

[stevem531]

Hi Atitudes

Just a couple more thoughts.

You could perhaps just check again the sound card settings by running alsamixer (ncurses version), and look especially at the Capture Options (F4 key) to make sure that the Line-in capture channel has not been muted (dotted lines being shown). Normal (unmuted) operation should show CAPTURE highlighted in Red. The keyboard Spacebar toggles the mute/unmute state.

Also check at the same time to look for perhaps an Input Selector Switch that allows the capture channel normally used by the Line-in input to be switched to any other input sources.


Some sound cards (even just the normal built-in ones) allow mixing of one or more inputs signals directly to the output. You might look in the alsamixer Playback (F3) settings to see if there is a slider for the Playback Volume level for the Line-in.

(I have never tried the GNOME Alsamixer but I understand that apart from a few enhancements and the nicer GUI interface it does much the same job as the ncurses alsamixer. I would expect that any sound card settings that GNOME Alsamixer changed can be changed back again using the ncurses version alsamixer).

Apart from the above though I am now running out of ideas.

You mentioned that you were planning just to try things out step by step and that seems to be the best way forward, and what I also try to do when faced with a problem to solve.

Hope that you get it sorted soon, and let us know how you get on.

Regards

Stephen

[Atitudes]

Thank you very much stevem531 for another excellent input. I still haven't managed to solve the situation, I will have more time to experiment during the upcoming week.

The alsamixer is a bit "tricky", I really have no idea about some of the options. Trying them one by one did not performed any desired change, I will try some combinations from now on registering the steps in order to be able to revert.

One thing I was thinking, but as I stated my knowledge is rather basic and this could be ridiculous but I will ask it anyway (I also found this post). I know that some users disables the PulseAudio driver and use only the Alsa-mixer configurations to configure their sound settings. My thoughts were to remove PulseAudio, re-boot and re-install it. Do you think it could make any difference? (just a thought...)

Thank you very much for your kind help and inputs.

[stevem531]

Hi Atitudes

I understand what you meant when you say that alsamixer is a bit "tricky". Even for just a normal built-in sound card there can be quite a large number of sliders and switches to control which can be a bit confusing.

As your system has PulseAudio you might consider installing the PulseAudio Volume Control (pavucontrol). This has a proper GUI and would allow you to more easily control many of the sound card settings, and it also features a 'bar' type level meter. I have pavucontrol on my system and I find it very useful at times.

If you leave the alsamixer terminal window open while running pavucontrol you should see the associated alsamixer settings change in response to any changes made in the pavucontrol settings. Also take care, (I expect that you already are), when experimenting with the sound settings and leave speakers & headphones unplugged until sure that the levels have been set correctly.

I would be inclined to leave the PulseAudio installation as it is though. I do not think that the process of de-installing and re-installing would necessarily fix the sound card issue, and it brings with it at least some risk of introducing other problems.

I will leave you to try out a few more options over the next few days. Please let us know how it is going and if there are any other questions that arise.


Regards

Stephen

[Atitudes]

Hi stevem531!

I performed some more experiences today without getting any luck... I did not mess with the PulseAudio installation but did installed the pavucontrol as per your suggestion. It did not provided any help with regards to my issue unfortunately but thank you for the suggestion, I did not knew about its existence. In fact, I managed somehow to be able to record through the Line-in but now I detected another problem I wasn't aware: the Line-in can't be muted while recording, it plays through even if I check/uncheck the mute options either in pavucontrol or in the normal sound managing options from the system settings. As you can imagine, it can be a bit annoying while recording voices/instruments while having a playback track and an amp screaming by my side...

For now, I think I will resign myself for the Mic input but I am quite unhappy as my Line-in seemed to have a nice dB cut (around 6/8 dB) that was perfect for some recording e.g. guitar through Guitarix (Line-in), with voice (Mic)... Unfortunately, I am back to the old days now

From my experience, it is better to try again in a few days since I sometimes solve issues without even knowing how I did it! It seems stupid but it is true! I fought as a mad man to get QJack, Guitarix, Hydrogen and Ardour or Audacity to work all together with a USB mixer for a long time without any success. I left it alone and forgot about it for some weeks and when I got back on it, surprise! Managed to put everything working perfectly, QJack wasn't bugging or crashing without knowing why, Ardour and Guitarix recognized everything and I could finally have some fun with the connection settings. Even working with Reason was a real pleasure!!

Anyway, that was just an outburst; I really hope some expert could solve my issue with some magical powder, it would be a treat to my ears


Once again, thank you very much for your help and do not hesitate to drop more useful tips, I most appreciate and I will give updates to the situation if any changes arise.

Cheers!

[Atitudes]

And after some more experiments, nothing good happened so far

As I've seen many queries for the https://wiki.ubuntu.com/Audio/AlsaInfo output, here is mine in case it may provide some gentle help http://www.alsa-project.org/db/?f=e9...36222b9e416492

Thanks in advance, I'll keep posting my new findings.

Cheers!

[stevem531]

Hi Atitudes

I have had a look at the Alsainfo output and from my understanding of the mixer controls there is a fader and mute switches for 'Line Playback Volume'. It seems that this is unmuted, and the fader turned up. If you are still hearing the sound from the Line Input continuously, I think this could be the cause.

You should be able to see the fader and mute controls in the PLAYBACK (F3) option in alsamixer, but it might need use of the left/right arrow keys to scroll them into the window.

I note that there are also similar controls listed for front and rear mic but they are muted and/or the levels turned down which would explain why the Mic input is not heard at the output, only the Line input.

Something to try anyway. Let us know how you get on. In any case it was a really good idea to post the Alsainfo as it will contain much of the info the 'Sound Gurus' might need.

Regards

Stephen