Top right, I click the sound icon, select sound settings, and connect my USB-headset. I can them see the headset being detected as it pops up in the menu. I click it, and expect the currently played audio to get sent to the headset instead. My problem is that it does not. The audio keeps playing through the built-in speakers.
More info:
The icon for my built-in card in the sound settings is a circuit with a note symbol on top. The symbol for the headset is just black background with a "No" symbol on it. Might mean it doesn't work somehow.
I installed pavucontrol, and notice that no second sound card shows up in there.
When connecting, the syslog says
Jun 20 09:38:46 yuna kernel: [40144.553431] usb 2-1.2: new full-speed USB device number 11 using ehci_hcd
Jun 20 09:38:46 yuna kernel: [40144.650609] input: C-Media USB Headphone Set as /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2/2-1.2:1.3/input/input20
Jun 20 09:38:46 yuna kernel: [40144.650895] generic-usb 0003:0D8C:000C.000B: input,hidraw0: USB HID v1.00 Device [C-Media USB Headphone Set ] on usb-0000:00:1d.0-1.2/input3
Jun 20 09:38:46 yuna mtp-probe: checking bus 2, device 11: "/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2"
Jun 20 09:38:46 yuna mtp-probe: bus: 2, device: 11 was not an MTP device
