How to connect Digital PC to Hifi?


Hi Folks!

I have stored about 500 hours of my favorite recordings onto a computer hard drive drive. I'm currently using a cable to connect my computer from the headphone jack of the computer to a tape input of the hifi. This is okay but there is a noticeable loss of signal when comparing the input from the CD player. I noticed that the receiver we use has several digital audio inputs....

The question: where can I find a piece of hardware for creating a digital audio output from my computer? The other question is what software can be programmed to output to this hardware?

~Thanks~
lebenz