If you don't have sound, even though the application's volume is turned all the way up, Puredyne's audio channels might be muted. You can unmute the audio using a simple application.
Volume Control using a GUI
Open up Mixer, it is located in the Puredyne menu under Audio -> Mixer.
Make sure that the sliders of the channels you are using are not all the way at the bottom (muted) and the mute buttons off. If so, turn them up to your desired level. If you don't see any sliders at all, you might have to add the specific controls first. No worries, its simple. Click on the "Select Controls" button and you will be presented with a small list of controls available:
Select the ones you need (or all of them) and go back to step 1 adjusting the levels.
Volume Control using a terminal
You can also control the volume using alsamixer. Open a terminal and type alsamixer and ENTER. Alsamixer is started.
You can navigate using your keyboards arrow-keys. Left and right arrows select different channels, and up and down arrows control the level of a channel.
If you have no sound, it could be that one of the channels is muted. Channels that are muted have a MM at the bottom of the channel. The levels can still be turned all the way up (see image below).
To un-mute a channel, select it using the arrow keys, and press M. The MM at the bottom of the channel should be replaced with 00.
Advanced sound module tweaking
For some cards some tweaking is required, for example you need to pass some arguments to the sound driver (module) in order to work properly. This is usually the case for exotic, rare or very recent hardware.
Reloading Alsa modules
There are different reasons why you would need to reload entirely the Alsa modules, for example:
- some modules crashed or your manually removed some and don't know which ones need to be reloaded
- udev is making a mess of your cards order, ie you specified in alsaconf that you want your internal sound card to be card0, but it ends up being card1 every now and then during boot time.
- something weird is going on and you need to reload the whole sound system without having to reboot
Use this command
sudo alsa force-reload