That's a great Q, and sort of like asking if a great turntable, arm, and stylus may sound better than a good entry level turntable.
If you play disks through a PLAYER with DAC's (transports don't have DAC's), the PLAYER's DAC's produce analog signals. Now, they need to be converted back to digital in your processor, then, recoverted back to analog with the pro's DAC's. That process can sound funny and washed out.
This re-explains a couple members recommendations for additional clarity. I would recommend determining your best audio TRANSPORT connections first by reading both the CD players' and processors' manuals or calling them, then, connect your player as a strict transport. That bipasses the player's internal DAC's and sends pure digital signals to your pro.
Read the components spec sheets and look for required input and output specs. These technical specs need to match between your transport and pro for the best sound.
System-matching components together seems to be the holy grail in digital sound.
I use a separate system-matched transport for redbook, DTS, HDCD's, etc., and a OPPO 981 for multi-channel music and videos only.
For less than perfectly system-matched components, I've had the best results using glass optical digital cables. Optical cables bipass some technical sheet recommendations for wire connections. A glass optical cable may be best for your current CD player when set-up in the strict transport mode - again, read the tech sheets recommendations. You'll have to AB-test the digital cables and connections for comparison. I like Van Den Hul glass cables very much.
A great system-matched transport for redbooks, DTS, HDCD, etc., is hard to beat. I had to buy one myself to believe it.
