Comment 7 for bug 619194

Also please look at another "master channel" issue.

For example Analog output selected. You press hardware volume buttons on laptop or change volume using tray icon - volume of analog output changed, everything is fine.
If you select digital output as main channel in KMix, you get this result: change volume using hardware buttons is work as expected, but if you click to KMix tray icon, you will see Analog output volume slider.