I still have a CD 3.1X (as my spare player). I changed the two output/coupling caps to Aura caps and had an entirely different and new player. And that was before their new teflon caps were available. This is a 15 minute effort so I highly recommend it. Hens' suggestion to simply insert a new DAC is probably your best solution for an upgrade. In the $1-2,000 there are some good options. Also $3000 DACS can be bought used in this price range too.
Looking to upgrade Audio Note CD-2
Although this is still a good unit, it is ten years old. I would like to hear recommendations of "better", newer units that would bring me into this century- anywhere between $1000- $2000. Tube or SS. New or used. Please don't suggest streaming, it's not for me. Thanks in advance, and best wishes to everyone. Xrayz