Replacement CD Player?

FWIW - been listening to my Hegel CDP-4 lately, first CDP I’ve owned that takes me beyond comparing CDs to my much more expensive and preferred medium vinyl rig.  I just forget about thinking ‘what’s better’ (and why) and enjoy listening to music. Fantastic player.  I’ve owned Marantz, Electrocompaniet, Jungson, and NAD players and the Hegel sounds so much more like analog it’s just not a fair comparison.  Highly recommended.  Zero shortcomings I can think of;  it no longer feels like a compromise when I cue up a CD. 

Good deal OP
Now just enjoy

Thanks everyone for the helpful responses. I went with the Oppo 203 and connected it to my 561 via the optical ports. 

Very pleased with the result!

As stated the main difference between203 and 205 ( just like 103 and 105) is in the audio.
The 205 has much better built in DAC than 203.
But if you are going to use just as a transport then yes it would be a total waste of money. However the 205 might be more of a future proof purchase if you also decided to change your preamp at any time.
Your choice.....

Thanks everyone for the feedback. So I think the Oppo UDP-203 at $599 will likely fit the bill with its optical output (plus a couple of nice extra features like the USB on the front). Based on everyone's input I'm not sure the 205 is worth the extra $600?

If Bluray is not important but occasionally still useful a cheap Bluray player is also a good idea. Unfortunately many of the cheaper ones no longer have optical audio outputs, so you would need to inspect the specifications carefully. Most Playstations will do the job, however.

 I second the Oppo 205 recommendation.  @willemj makes a great point in that you can still use the digital inputs on Meridian.  So if you find the Oppo somewhat disappointing just use it as a transport.
However you will gain all the flexibility that mentions.  Even if you don’t need or want it’s file playing capabilities you may want to purchase some Blu Ray Concerts

However, the OP does not really need a complete CD player. A normal CD player essentially consists of two parts, the drive/laser assembly that produces a robust digital signal (for years Meridian just like many other high end manufacturers used bog standard Philips asemblies), and a DAC that converts that digital signal into an analogue signal.
Thanks to robust error correction, the digital signal is a bit perfect copy of the original recorded file (see here for an explanation of digital error correction: http://abcnews.go.com/Technology/story?id=119305&page=1) So whatever your player, and as long as you have not totally destroyed the disc, the digital file will be the same bit perfect file. Sonic differences (though quite small) only emerge afterwards, when the digital file is converted into an analogue stream. Since the OP already has a digital to analogue converter in his pre amp/processor all he needs is a player with a digital output (preferably optical in his case). Whatever player he uses, as long as he uses the digital output, there will be no sonic differences. So he might as well use that old Sony Playstation 3, or whatever he has or buys cheaply. The only two things to consider are the mechanical noise level of the drive (that proverbial Playstation is pretty noisy) and the convenience of the user interface. But make sure it has an optical output.

Two CD only players that I would consider in your price range (new).

Exposure 2010

http://shop.generubinaudio.com/Exposure-2010S2-CD-Player-132698575963.htm

Musical Fidelity M3

https://www.musicdirect.com/disc-player/musical-fidelity-m3scd-cd-player-dac

http://www.audioadvisor.com/prodinfo.asp?number=MFM3SCD


Rich 

The 508-24 was one of the best in its era. I'm not sure that $1500 would capture what the Meridian had to offer. The Hegel cd-only players are at the top of the game today, but expensive. Rega, Arcam, and Cambridge Audio, as well as Marantz and Yamaha are making very fine players these days.

The biggest difference is in the audio part. But you have a cheap alternative. Since your Meridian 561 DSC has an optical digital input you only need a pretty basic cd player, as long as it has an optical output (or coax if you are willing to put up with a - simple - coaxial to optical converter). The part of the cd player that is responsible for the sound quality is essentially the DAC (digital to analogue converter), and you already have that in your Meridian 561 DSC. In fact, you also have optical inputs on the speakers  - I am not quite sure how these units combine. What is the purpose of the 561 DSC?

If I’m only interested in using it as a CD player would the 205 be worth the extra expense over the 203?

Oppo UDP 205? It is not only a very fine CD player, but it will also play many other formats, up to and including UHD Bluray (for your opera recordings, or to get good sound playing movies on your TV). It also has additional digital inputs, if you want to add something like an external streamer. It has a variable output, so you no longer need a pre amplifier, and both rca and xlr connections.