Bad combination. :(
You have to change to the Oppo 105, which has USB 2.0 outputs, OR change your DAC.
I like the 9, but it’s VERY source fussy. I haven’t heard the Codex, but hear good things about it. How about a Mytek 192? About $1k new since it’s discontinued (direct from Mytek) and will take optical and coax inputs.