Upgrade CD, New CD or Universal Player?

I have an ARCAM CD72 and a Marantz 6005 AVR driving it. Got new B&W 683's but do not hear a huge difference when playing CD's. Is it better to upgrade the CD72, get a new CD player or go with a universal player? I have read good things about the OPPO BDP 95 (we have a BDP 93 for home cinema). Thanks for advice.
"Is it better to upgrade the CD72, get a new CD player or go with a universal player?"

Neither. Get rid of the Marantz. There's nothing wrong with it but it is clearly the weakest link in your system. Something like a matching Arcam integrated would make a huge difference in sound quality.
Check out the Arcam DVD-139 listed on Audiogon.

No interest or relationship to the seller.
I had an Arcam AVR100 but it developed a buzz I could not resolve. What if I added a nice amp (was looking at the Parasound A52)- would that improve sound or would it just magnify the Marantz?
I second the idea of getting the Marantz out of the chain. I used a Marantz 7001 AVR as a preamp for a long time, and when I finally got a real two-channel integrated (Cambridge 850A v2) it was like someone took a blanket off my speakers.
You are getting good advice. Using the Marantz AVR and expecting better CD sound struck me as the odd statement. What is your budget at this point (including the possible resale of the Marantz) and you can probably get good recommendations for an integrated amp.

Being a novice, if I dump the AVR I need a pre-amp and amp, right? I have a 5.1 speaker system. Guess I could spend another $1500-$2000 if I had to.
FYI, I appreciate the advice. Going with an Integra 40.2 for the pre-amp, and a Parasound A52 for amp. Got a deal on both.
I don't know much about the 40.2 but the A52 should make a very big improvement in sound quality. Once you have a chance to listen your new gear, please post and tell us what you think.