" They can take a garbage source and make it CD quality, can they? "
No, and don't let anyone tell you different (some people will actually try to argue that.). MP-3 is lossy. When you rip a CD to MP-3 files, information is lost in the process, and you can't get it back. Not to be confused with losless compression like FLAC. The information is compressed to make the file size smaller, but you get it all back when its decoded.
Is it worth getting a dac for MP-3's? Its hard to say. I would pick up a Dragonfly from Best Buy and try it. It can always be returned. If your files were CD quality (16/44) and above, then yess, a dac would be a sensable upgrade.
No, and don't let anyone tell you different (some people will actually try to argue that.). MP-3 is lossy. When you rip a CD to MP-3 files, information is lost in the process, and you can't get it back. Not to be confused with losless compression like FLAC. The information is compressed to make the file size smaller, but you get it all back when its decoded.
Is it worth getting a dac for MP-3's? Its hard to say. I would pick up a Dragonfly from Best Buy and try it. It can always be returned. If your files were CD quality (16/44) and above, then yess, a dac would be a sensable upgrade.