XLR to RCA adapters

With a fully balanced CD player and pre-amp, and a power amp that is RCA only, should I use an XLR to RCA adapter to the amp? Would there be audible losses, perhaps in noise floor, compared to using an amp with balanced inputs?
In this case it would be the Acoustic Reality Enigma, which is RCA only, or the PS Audio HCA-2, which has the XLRs.
Another related question, for people using the Panasonic XR45 with the Behringer crossover. The Behringer is fully balanced and the XR45 is not. I assume that XLR to RCA adapters are being used?
Thanks, Sonny
I use to use rca to xlr hybrid connector from cdp to preamp. that was with an Aleph P and X600 monos. I wanted to take advantage of the increased balanced gain feature of my preamp. Everything sounded fine. Then I got the eAR2 and it sounded awful with the same hybrid. Replacing the hybrid with a fully rca connector solved the problem. Now the eAR sounds fantastic.
Muralman, If your eAR2 and your pre are fully balanced, wouldn't you benefit by having a CD player that is balanced as well? I have read that if equipment is balanced, it would sound better using it that way. Sonny
The Aleph P and the eAR are fully balanced. My CDP is not. Actually it is not a CDP, it is a DVDROM. All I know, is going RCA with my rig is so much better than balanced with any other rig, there is no question rca is better in my experience. If one is trying to maintain a balanced system, then they will have to use a balanced front end. Using hybrid cables is not the way to go aboout things.

I will be auditioning fully balanced sacdp soon.