RCA to XLR connection

Why not just buy your favorite cables and have the vendors convert them instead of using the converters that, no matter how good they are built, almost always degrade the sound. Most cable makers can do it with a little extra charge. Nonetheless, you must specify the configuration (pin2 negative or ground).

I don't have their web address, but find a company out of Texas called Milestek. They sell a variety of audio/computer related products. They have the excellent Neutrik adaptors in a variety of configurations for $12/each. You do not have to pay alot of money very good adaptors.

Here's the exact webpage of the adaptors the milestek makes, they have all kinds of different configurations Male RCA to Male XLR I think is what you're looking for though.

http://www.milestek.com/interseriesadapt.htm

goodluck

Another option:
When I owned an Audio Research LS-5 MKIII (only built with balanced inputs/outputs), this unit came supplied with XLR/rca adaptors that had excellent build quality. I believe Audio Research still sells them. Good luck.

Another source (have not bought from them though)http://www.markertek.com/MTStore/product.CFM?BaseItem=HK-110M