A good few years ago I auditioned so many CD Transport/DAC/CD Players I could get hold of. I came to only one that satisfied - THETA.
Expensive, but well built and sounds amazing - still working like a dream and still sounds fantastic. Occasionally available second hand.
The designer is called Mike Moffat, and he now co-owns Schiit Audio.
If I was going to buy a replacement for Theta, that is the first place I'd look.