Getting sound from the computer to home stereo

I have a HP pavivillon PC with a built in sound device.  I would like
to here the sound output from the computer on my home stereo.  I know
that you can connect the stereo to the PC through the line out on the
sound card.  But what do you do if the sound card requires powered
speakers? I tried to connect the stereo from this output but no sound
from the stereo.  Any suggestions would be appreciated.  Thank you.