Streaming Equipment and Sound Quality

Please correct me if I'm wrong here. Will music 320 downloads on your computer sound not as good over a stereo system as CDs? If the answer is no, then I wouldn't be interested in buying a device that plays downloaded music over my stereo system. If the answer is, it sounds comparable, what streaming equipment that produces great sound would you recommend? I'm not sure if I worded this correctly. At times I've converted downloaded music to CDs but I've never played just download music directly through my stereo system.
Downloaded 320 mpgs won’t sound as good as CDs when both are played through a good system. Downloaded FLAC files are more popular among audiophiles, and to my ears, they can sound as good as or better than physical CDs. The difference is entirely in what equipment you use for each source.

mp3 files are great for the car or portable player or for background music, in my opinion, and can be quite enjoyable in such uses. But they wind up sounding a little flat when compared to lossless files or CDs on a very good audio system in a quiet environment.