Adding to my previous post, if what you are referring to is continuing to use balanced cabling, but using an XLR to RCA adapter at its end to adapt to an RCA input, that too would defeat the noise and ground loop-related benefits of a balanced interface. It would also change the configuration of the input circuit that is being used, and it might reduce system gain by 6 db. Also, and perhaps most significantly, many XLR to RCA adapters short one of the two signals in the balanced signal pair (usually and perhaps always the one on pin 3) to ground (pin 1), and depending on its design the output stage of the component driving the cable might not react well to that. I believe, btw, that Cardas adapters are one of those that do NOT short pin 3 to ground, on XLR female to RCA male adapters. (Pin 3 SHOULD be shorted to ground on XLR male to RCA female adapters).
Regards,
-- Al