Okay to use RCA adapter on a fully balanced amp?

So, with your amp you paid a lot extra because the manufacturer had to create two independent channels instead of just one, which ups the parts count and price considerably and you basically lose that benefit by sending it an unbalanced signal.  Use a fully-balanced preamp would be my suggestion.

You likely will experiience no difference. However, instead of an adapter, I would make or have made a quality cable with XLR on one end and RCA on the other.

@soix   You are assuming there is an inherent benefit to balanced cables.  Many, if not most, do not agree with that assumption.  Having multiple inputs=good.  Having ability to accomodate both xlr and rca=good.  Needing another RCA because your component doesn't have xlr out=common problem.

On a normal 1 meter cord, you won’t hear the difference, but on longer runs, XLR. 

Using an adapter as you stated in your original question technically will create additional noise on the line, I have no idea if you will detect the noise.

Not really concerned about the noise or if XLR is better, the only thing I'm worried about is the quote again.....I've never heard of this before and don't want to only get partial power from my amp.

"The MEGAschino is a true fully balanced differential amplifier from input to output. It is essentially two  amps for each channel, and one amp per phase. This means it really should be used in a fully balanced system.The manufacturer supplies an XLR to RCA adapter, but these should not be used. If a balanced connection cannot be used, note that the amp cannot be driven to full power from a 2-volt single-ended output, the limit of most receivers."