There we go. In my older pc I only had one soundcard so I never needed something to change the devices. In my new pc I do have 1 onboard card and a Soundblaster card (7.1, no, not enough speakers
Switching between them means plugin out the headphone from the front of the pc to one of the speakers to listen with the headset. Unplugging the headset if I want it through the speakers. Rather annoying so I was looking for a solution to do it with some kind of menu entry. So glad all the standard stuff is there. I can now switch with a single mouse click using a gnome extention.