In the Amarok Settings menu, select 'configure amarok', engine. See if there is a sound engine selected (choose one if not set).
If that doesn't work, try starting Amarok from the command line, and watch for error messages as a means of debugging the problem.
I'm not acquainted with SoundKonverter. I use grip to rip cds or convert from one format to another. In the grip configurations, you can specify the input file format (mp3) and the output format (ogg).
Remember that both mp3 and ogg are lossy formats. Converting from one to another may not produce acceptable results. I find it better to rip from wav to ogg, or wav to mp3, but not mp3 to ogg or vice versa.