303 can be used as transport using its digital outs. but the 306 has digital inputs so it can be a processor too for external sources.
what you are paying for in the difference between these 2 units are the dacs and audio output section on the 306, really (plus the 306 inputs i guess).
the 306 offers upsampling dacs that are burr brown 1704s which are 24 bit dacs.
the 303 also uses the 1704s (one per channel whereas the 306 uses 4 per channel). Both are using the PMD 200 filter.
Personally, I have preferred the 303/200 cd player to the more expensive 306 player. I thought it had more life to it. I'm not convinced that multi-dacs in parallel improves things at all... its all a bit of a hack. Certainly upsampling is a good thing, but the latest 303 has the same PMD 200 which I think does the upsampling as well as the HDCD decoding.
I've really enjoyed the 303 and not loved the 306 as much.
Talking to Dennis Had, owner of Cary, he outsources the design of both components to a group in Japan. I was wondering how he could be both an expert in analog tube amp design and digital cd design. he is not.
My recommendation is to listen to both in your system. I liked the 303 better, but that's just me I guess...
Ensure you get the metal remote control. The guy who makes the cool metal remote is retiring and they are replacing with a crap-plastic remote....
