Balanced to RCA adaptors

I have a system using all XLR cables, and recently ordered a new preamp that is all RCA. (No choice here)
I am wondering, should I switch all my IC's to RCA, or can I just use the XLR to RCA Cardas adaptors and not have a sound degredation? If I do use the adaptors, do I need to use them at both ends of the IC or can I leave the amp end plugged in with XLR and the preamp end plugged in using the adaptor, to the RCA connection?