I just started having this problem today:

Every song change, my PCM volume is set to 0 and I can't hear anymore music.  No settings were changed that I can remember.  Any suggestions?

well, normally we would suggest you give some detail, what engine, etc, but almost certainly you are having this problem:

http://amarok.kde.org/forum/index.php/t ... 595.0.html

yes sorry about not giving information but that solved it. thank you.