Digital

A lot of audio equipment has a digital input (optical or coax).

You won’t find many computers with a digital out (SPDIF).
Sometimes the headphone out doubles as a digital out (Toslink)
Apple, Toshiba, Asus and in general multi media models offers this type of output.

 

If your PC doesn't have SPDIF this might a matter of not having a receptacle.
Often there is SPDIF out on the motherboard.
If you don't mind a bit of DIY you can make your own SPDIF out.
http://projects.loetaffe.de/index.php?option=com_content&task=view&id=34&Itemid=12


Every PC has USB but very few audio equipment has a USB input.
Except of course for the USB speakers but these are targeted at the desktop.
Slowly but surely the audio world recognize the impact of computer based audio and starts to produce audio equipment with a USB input.

 

In practice you have two major options to connect your computer digitally to your audio.

©Vincent Kars