Every digital format out there, whether CD, DVD, SACD, or streaming in any format CD or greater is as good as you are, you being a human being, and better than your speakers by a fair amount. Stop worrying about the format, and start worrying about the recording. There could be 10 different versions of a recording, one of them may only be on CD. It will be the best one, not because it is CD, but because it is the best mix. Same could be true on SACD. Same could be true with a streamed version. I would suggest learning to stream locally. You can rip CDs perfectly using a computer. The computer can take multiple passes to reduce errors. You can purchase and download some SACD recordings.
@kraftwerkturbo if there is a big difference in the analog in of the receiver and digital, then you are using a processing mode of the receiver, not pure amplification. The levels are likely to be different which makes a difference in the sound.
