I posted this in neighboring discussion recently:
I will describe to you my experience, not what I had read or heard from others. I bought Denafrips Ares II and utilized Arcam CD192 as a transport, it was great improvement, then I replaced Arcam with Cambridge CXC transport that was very noticeable improvement over Arcam transport section. I did go further up the ladder since. I have learned from my own experience that dedicated transport matters.
Now I am using Jay's Audio CDT2-MK3 with Denafrips Venus II 12th it is impressive improvement in comparison to Cambridge/AresII. Also, the HDMI connection over coaxial makes considerable difference, mostly much greater three dimensionality and placement of the instruments using HDMI. I do agree with Harley that a DAC makes greater difference then transport. My experience.