Linux software mixing

Am I right in understanding that in Linux you can hear sound in all your applications, but you just don't have a PCM control when you run alsamixer and select your card (F6)?

Do you mind showing the output of cat /proc/asound/modules, cat /proc/asound/cards and aplay -L?

If you're just missing a PCM control I suspect something like step 5 from the Dmix wiki is all you need, though I know you mentioned having problems with dmix before.

Is alsa-lib installed from your distro repo?  

Can you control your volume via amixer?

Do the following terminal commands work for you? 

amixer -c 0 -- sset Master playback 5dB+
amixer -c 0 -- sset Master playback 5dB-
amixer -c 0 -- sset Master playback mute
amixer -c 0 -- sset Master playback unmute

Thanks for the info shrimants. This should be your ~/.asoundrc file:

pcm.softvol {
    type softvol

    slave {
        pcm "front:DAC"
    }

    control {
        name "Master" # This can be called whatever you like.
        card 0
    }
}

We just told ALSA to control your DAC volume using the softvol device (built-in by ALSA). front:DAC was taken from your output of aplay -L as the name of your 2-channel output device.

card 0 tells ALSA that the new control should use your default soundcard. In troubleshooting your issue using my FiiO E10 (which also uses the snd_usb_audio module) I wasn't able to get dmix working using a !default statement in .asoundrc.

The latest version of ALSA (1.0.24.1 at the time of writing) will dmix the default soundcard automatically, letting multiple applications output sound at the same time. As a workaround to ensure that your Gamma2 is the default card, you can use a parameter for snd_usb_audio setting it as default whenever it's loaded. If your Linux distro has an /etc/modprobe.d/ directory (as root) create a file called sound.conf there that reads:

options snd_usb_audio index=0
options snd_hda_intel index=1 # Optional.  Just showing that you can create a list
                              # of your cards in order of preference like this.

If your distro doesn't use /etc/modprobe.d/ it might instead have a file called /etc/modprobe.conf. You should be able to place the above parameters there.

If all else fails you can manually remove all your ALSA modules then re-add only snd_usb_audio (so that it's forced to be default) when your computer boots. Slackware has a file called /etc/rc.d/rc.local for the purpose of executing commands at startup but your distro may use something else. The contents of such a file would look like:

rmmod snd_usb_audio
rmmod snd_hda_intel
modprobe snd_usb_audio

After restarting your computer run the command cat /proc/asound/cards to verify that your Gamma2 is the default. Then try speaker-test -D softvol -c 2 -t wav to test sound. Once you've run that command your new volume control should be visible with alsamixer.

After all that you may find that even with your volume control at 100% it's not loud enough. Here's a short example of how to create an ALSA pre-amp though I haven't tried it myself.

For more on softvol this ALSA wiki page was really helpful.

I have ubuntu 11.10 which supports sound from a Zotac mini-itx just fine... except when the Fubar DAC is connected.  Then it only works with the VLC media player.

Quote:

Originally Posted by fubar3 

I have ubuntu 11.10 which supports sound from a Zotac mini-itx just fine... except when the Fubar DAC is connected.  Then it only works with the VLC media player.

Ubuntu uses PulseAudio as its default sound server.  You may want to reinstall its components to make sure you're not missing anything:

sudo apt-get install libasound2-plugins "pulseaudio-*" paman padevchooser paprefs pavucontrol pavumeter

Could you then report what audio output plugin VLC is using? You ought to see it under Tools -> Preferences -> Audio -> Output from the menu. If it's set to Default try changing it to ALSA, replay your file and see if you can hear anything. Then try it again with PulseAudio.

Quote:

Originally Posted by shrimants 

Alright, I've tried what was suggested and still no luck. I've rebooted and such and I keep getting the error "Unable to find simple control 'Master', 0".
The sound.conf option has worked. Now USB audio is my default device and HDA Intel is my card "1"/fallback. The asoundrc is still wrong, however. I'm using archlinux with openbox. My volume frontend is "volwheel" though i'm open to suggestions for a different program. I was hoping to avoid having to mess around with Pulseaudio because I'd have to configure every single application independently and the thought of having to redo it if my system collapses makes me shudder.
i do have parts for a passive preamp so I suppose its not too big of a deal now that USB is at least my default sound card. I just have to figure out how to make perf board accomodate the gigantic pins of my RCA jacks. I'm pretty sure I can simply drill the perf board to size but I dont want to ruin the perf board by accident.
EDIT: Alright, I found the source of that error in my main TTY1. Its coming from volwheel, which was attempting to control the volume of the "master" channel. The volume control still isnt there, however. I think the only way I'll be able to get volume control is via hardware methods or via pulseaudio, which runs as a sort of server before actual hardware interaction. Dmix seems to be unable to deal with this sound chip (PCM2707). Thanks anyways for the help with setting default sound cards. That is a way better solution that the asoundrc !default statements IMO.

I'm glad setting the module parameter worked for you. Designating a default device might get more complicated if you add a second device that uses snd_usb_audio.

Volume Icon seems like a good replacement for volwheel. I was able to create a new volume control and Volume Icon manipulated it without any problems. I even managed to get the new control working with dmix.

Volume Icon's available from the AUR. It can be compiled with support for native desktop notifications (which appears to be disabled at the moment in the AUR package according to that page's comments) but I didn't like it. Its notification was blank for me.

Not associated with volwheel, I also tried GVolWheel but I didn't get far. It's interface was too kludgy for me (its slider kept popping up behind my AWN bar).

Just a reminder, as it notes on the ALSA softvol wiki, a program has to use your new mixer element before it can be seen (!) by alsamixer or whatnot. That step's really unintuitive for me.

Quote:

Originally Posted by shrimants 

Dmix seems to be unable to deal with this sound chip (PCM2707)

Sorry, I missed that bit.  That's unfortunate.