Asus M3A / Realtek ALC883: Cannot change connected device in SoundManager

[SoWhy]

Hi,

I recently upgraded my motherboard and replaced my MSI K9N-Neo F with a Asus M3A. Both have a Realtek HD Audio chipset, as far as I know of very similar design. With my old motherboard, I used the black connector to reroute the same signal as with the green one to my headset (so my speakers and my headset had the same signal (=audio out)). I could set this with the Sound Manager in the "Audio I/O" tab.

I installed the drivers for the audio codec with the new board and I had the same Sound Manager, but with this version, I can't change the connected devices (by clicking the symbols). How can I get back the functionality I had before?

TIA
SoWhy