Just hook them up to the old fashioned red/white CD connections on your receiver.
However, how much better it will sound also depends on your receiver. Some have a "stereo direct" setting which causes their analog inputs to completely bypass any internal digital circuitry. Some do not. Redigitizing the analog output of a quality DAC defeats the purpose. That's why some people invest in a separate analog stereo system.
I'm half way there. I'm looking for an older receiver from the 70's to suit my needs, however in the meantime the 2808 will do.
It does have a Pure Direct Mode which is different than the Direct/Stereo Mode it also has. I have read that is bypasses all the circuitry inside. Anyways, I'll eventually get an amp/receiver for 2 channel stereo, but then that also includes new speakers...so, I hope this sounds good for the time being.