Is using an Apple Computer a weak link...?

Absolutely. With that level of gear you would definitely benefit from a dedicated streamer.

Dough...! So I could actually use the Aurender A10 as a server using the USB out...????

I would appreciate some clarification w/r to this discussion:
(1) I am under the impression that the "effect" of a computer on sound quality depends on the software used to send the music file to the DAC.  For example, I have read that if you have a MacPro ("desktop" not laptop) and use Audirvana that since Audirvana takes control of the reading/interpretation/transmission of the music files that there is no decrement in sound quality vs a dedicated server.
(2) I have read that if you use an ethernet connection (rather than USB) from the Mac to the DAC, that there is no loss of sound quality vs a dedicated server
(3) I have also read that if you are using music files (FLAC, DSD) stored on the Mac (vs. streaming from Qobuz or Tidal or Amazon) that there is no difference in sound quality vs having a dedicated server.
If anyone has actual experience with these scenarios or conditions, please provide your experience and opinion.  Thank you

Craig - All very good questions…!

I'm curious WHY you want to go from The Aurender A10 to a Desktop unless you can't use it as a dedicated streamer. But I'll stick around and maybe learn some more.