The digital out on a CD player just sends the digital stream from the CD (with error correction and interpolation applied) to the DAC at the other end. So your player is working as a CD transport, just as the Cambridge would.
It's possible that the Cambridge has a better drive mechanism, but I doubt you'd notice. Compare the two on the basis of looks, features, quality of the remote if any, etc.
From Yamaha's website:
So Pure DIrect does the opposite of what you wanted.
My advice these days is, where possible, only to buy a device where you can download and read the manual online, or find a comprehensive description of what the product does, before purchase.
Basic measurements, at least, as well, for the purpose you have in mind, if available.
Never assume.