All right
@Marplot and
@LuvMyQuad,
I think I have finally got it.
STEREO: the DSD conversion (24bit, zero compression) either 88.2 or 44.1 sample rate, both played well through the UConnect but the 88.2 had a little tiny hiss that the 44.1 did not have. I am referencing in the quiet of my garage, probably would not notice the difference while driving.
The winner of the Stereo is any format they come as, no conversion, except DSD to FLAC that conversion will be zero compression, 24 bit, 44.1 sample rate. USB SSD 5TB Format NTSF.
5.1 playing through decoder: Tried a 24/96 file as it comes and the decoder sounded like a little lag, like too big but played in surround, clearly.
Tried 24/48 with 6 compression, again played well but something not quite right.
Tried 24/48 with 0 compression, perfect, the winner. USB FAT32. 32 Gig.
All right, thanks for all the help, I feel pretty comfortable with the plan, and not thinking my Chinese decoder that came from who knows where is no good, maybe it is perfect if you play the way it wants to play.
You cannot be an audiophile if you do not have the help of others on QQ, thanks much.
Will keep you posted after DSP tuning, which is the last step, probably this Thursday, I still have to work.