I have an M-Audio Delta 1010LT. You see, all of the card outputs start with DAC, and each output is mono. However, in pairs they act as stereo, i.e. DAC is left and DAC 2 is right, DAC 3 is left and DAC 4 is right, and so forth.



And then comes the problem - I can only control the volume of one of those at a time, which makes a simple task such as volume adjustment more of a pain than it should be. Adjusting the volume via the tray or the media keys on the keyboard only adjusts DAC, which pretty much makes that aspect useless.

Is there any way to link or join these two channels in KMix?

Whilst this is not possible from the KMix user interface, you could change the ALSA configuration, which may be able to make this function correctly.

You may also wish to check with (Right Click in KMix main window) > Device Channels.

Kmix doesn't really have any control over this, it gets its information from the underlying sound system.