FYI: I have been experimenting with a couple of 384kHz/32-bit FLAC music files and I found that the Pre-8 plays these files with no problem when rendered directly from my NAS through Volumio. There should not be any down conversion going on since the ESS Saber D/A chip in the Pre-8 should be able to easily render these files.
On the other hand, when the same files are served through LMS (Lyrion Music Server) through the LMS DNLA/UPnP bridge plug-in, the file appears to be playing when viewing its progress on the Volumio player screen, Though the Volumio screen states that the file is in-fact 384kHz/32-bit and progresses right along, I do not hear any sound. I’m still trying to figure this one out.