I have made the same experience with my Onkyo nr-807 receiver, streaming with dlna is a dramatic improvement to sound quality that outperforms any other connection method from the same PC.
In my DLNA Server setup I have made the following:
Conversion: Convert unsupported formats
Encoder: Uncompressed - L16 No header
In the Advanced section I have checked DLNA, DLNAExtra and Playstation 3 compatible
By the way, where do the filetype .Ma4 come from. I seemed to have missed that one. I do not think it is native supported by MC. Or you maybe have installed a codec for that separately.
Thanks for the setting info I am configuring it now. I apparently have either a Windows 8 problem or a Creative Soundblaster problem in play back. I am getting a frequent and very irritating momentary buzz in the play back which I don't have in Network streaming. It did this with an very old SB Audigy card and the brand new SB Recon 3D card that just replaced it. This is what I get for getting in on the ground floor of a Windows OS
I never though about it until now but I see your confusion with .Ma4 ? I have God only knows how many files with this codex noted, which is flat wrong the file extension should be .m4a. otherwise known as, ALE, ALAC, or Apple Lossless. Apparently people editing file tags have miss typed it. Since they play I have not given it a though. When I look at the detailed file name there it is in the extended file .m4a. I must have 4 or 500 gig's of .m4a files as if my file are not already royally screwed up by iTunes.
Thankfully JRiver has at least straightened things out for it's use.