Now that I have updated kernel and so on the audio is coming through quite nicely. However, I'm not particularly impressed with the sound stage. In fact I'm quite dissappointed.
I have an old Arcam Alpha 9 Amp that I purchased new which I have always used and recently migrated (due to apartment size requirements) an old Fatman iTube (minus the dock) which was night and day beautiful with the cheap FiiO D07. I was simply streaming from the Apple TV.
So the idea was to remove all the extra paths, use an old Raspberry Pi I had and see what the flagship DAC + Pro would do.
The sound is much clearer and crisper, though far less rounded. The dynamic range seems to have reduced in that the lower end is far less prominent - which isn't an issue in itself except that the tube amp sounds like I've gone back to transistors. I suspect if I plug the Arcam in, the sound will be even flatter.
I'm using Volumio and I suppose I could try Rune, but I doubt that will be any different. As an experiment I also tried Airplay and all that happened was it got softer, though other uneducated ears preferred the softness of airplay describing Volumio's direct play as like being in a bathroom!
The only upgrade I can think of is power supply.
Does anyone with more experience than me (I have only 1 day with HiFiBerry so far) want to suggest anything? I do have two new Russian NOS tubes ready to put in which might help.