Kubuntu 10.10 Maverick Meerkat comes with Amarok 2.3 pre-installed. For users of Kubuntu 10.04 Lucid Lynx, Amarok 2.3 will be among your normal updates.
Actually, in order to make it work, the package libxine1-ffmpeg is required, which probably isn't included in the default installation due to licensing issues. So, all you need to do is install the package and you are ready to amarok.
Libxine1-ffmpeg contains MPEG-related plugins used by libxine1, the media player library used by Xine engine, which Amarok and other xine-based players use. This package includes the ffmpeg plugin for Xine, enabling xine-based players a large variety of audio and video codecs.
sudo apt-get install libxine1-ffmpeg
Install Xine (if it is not there)
sudo apt-get install phonon-backend-xine
sudo aptitude install phonon-backend-gstreamer
Then you must restart Amarok.
If Still No Sound,
Open Amarok --> Setting --> Configure Amarok --> Playback --> Configure Phonon ( choose device)
if still No Sound,
System --> Preference --> Sound --> Hardware --> setting for the selected device (choose one)