Cdx2/Hdx/Hdx(ssd) bare sound quality

Of these three, based purely on SQ and not on what they do, which is the winner and why? 

I have searched for a similar thread and whilst one or other have been talked about many times before, I have not found a direct SQ comparison of all three in bare format ( without nDac or Xps2 which I am sure would improve all three to a certain extent).