No more speaker output, only headphone - Xonar ST

[frapelli]

Speakers doesn't work anymore. Alsamixer analog aoutput let me select only "Headphones" and "FP Headphones". In System settings phonon selecting speakers gives no sound, or sometimes the test sound comes fron headphones (in left / right test).

I thing it happened after last upgrade (with KDE 4.9), but not sure.

Thanks

P.S. For those who don't know, Xonar ST have different output for speakers and headphone, and you select via software (usually alsamixer, phonon or both) wich one you prefer. You do not have to switch plugs. So switching plugs is not the solution.

[Fitzcarraldo]

Which Phonon Backend are you using? VLC or GStreamer? Have you tried both?

Also, have you tried using PulseAudio Volume Control (pavucontrol) to select the output channels?