New CD Player

Haven’t heard the Onkyo and it may well be the best cd player on the market - but at its price range not overall

I find the Onkyo to be incredibly transparent and a little more forward sounding, the marantz a little more fuller and warmer. With the return policy of some online dealers you can try both which is what I would do. You will use this player for another 10 years, get the one that best suits your system. The Marantz is 30% off here:

https://www.accessories4less.com/make-a-store/item/marcd60blk-rb/marantz-marantz-cd60-single-disc-cd-player-w/usb/1.html

First, I am the distributor for CEC in the America's.

Since your CD player came on the market, there has been a major change in the design of laser pickups. This made a difference in the performance of CD transports across the board.

The idea that it is all one's and zero's, as a result all cd transports sound the same is not an accurate statement. The error correction used in transports is not all the same. Some transports with exotic error correction will nearly always play music, but is it what was originally recorded. NO and some audiophiles can hear this and don't appreciate it others do.

CEC transports use a belt drive system for the spindle this decreases the noise in the music. If you want to know more see the Audio Union web site.

Can’t refer to anything from your old player, but we are many generations later now in CD player technology. 
 

the Marantz for its price would be a great player if you don’t need SACD. 

$1,000 is likely reasonable. 
 

Cary Audio does upgrades to some of their gear. Maybe your gear qualifies for an upgrade? Perhaps contacting them would be a decent path. Any company that stands by their “obsolete” gear is ok in my book. Sonic Frontiers “The Parts Connexion” is another example of a company that performs such work.