I have a workstation running Platform Version 4.8.4 (4.8.4) fromt he Kubuntu backports PPA. I have disabled my internal audio cards using Pavucontrol. When I log in by default Kmix is running int he system tray with the speaker plugin, it shows the Dummy Ouput as master channel. When I plug in my headset (Logitech Clearchat) it does work, but the master channel does not pick the new (and only) headset as master channel, it is neither dummy, it becomes unselected, so the icon changes fromt he speaker to the Unknown icon, ie. white page with question mark in it.

Reproducable every time.

Reproducible: Always

Steps to Reproduce:
1. Disable onboard audio in pulse audio volumn control.
2. Log out and back in.
3. Kmix will show speaker icon with dummy output as master channel.
4. Connect USB headset
5. Icon will change to white page/unknown icon
6. Right clicking KMix and selecting the correct master channel (there is only the usb headset in a radio button that is currently unselected)
7. Speaker icon will reappear.


Expected Results:  
Either pick the new master channel automatically or leave it as dummy, although picking the new usb headset would be more user friendly given there is only one on my machine.