Can anyone recommend a smooth, rich CD player?

there is only one warm and rich cd player ever made, namely the cal tempest.

One of the smoothest richest sounding cd players was the venerable pioneer pd-65. Many now use it soley as a transport but it had a very smooth dac. If your system is treble bright or you want a rich sound this may be one of the best and cheapest ways to achieve your goals.

I would listen to the Cary 303/300. Listen to the tube output. It is special.

The Cayin 15, now updated to the 17 version really delivered="smooth/rich" with their tube outs.
I owned both and recently sold the 15.I paid $1K included ship last yr for the 17.

I second Entrope above with regard to introducing a tube if you want to veer towards a richer sound. Re the 508.24, I owned one and a/b'd it against a Granite 657 tube player. I and all who heard the comparison preferred the Granite. It wasn't even close (which surprised me because I'd heard such good things about the Merdian). The Meridian sounded thin--clear, but cool and analytical (too much so)--compared to the Granite. The Granite's tube output likely was part of the reason. The Granite's more $$ than your budget, but I'd check into the recommendations above that have a tube output. Surely you'll find one that sounds rich without sacrificing detail.