I’ve used xlr to rca adapters as a test. I’ve used them on a First Watt J2,and a pair of Monarchy Audio amps. I don’t run a balanced pre,but I wanted to see if there was a noticeable difference. I could not detect any. Now,if I was running a balanced pre, I’m guessing the outcome would have been different with end to end XLR cables.
Okay to use RCA adapter on a fully balanced amp?
Not a XLR is better or RCA is better question BUT if I have an amp (Digital Amplifier Co) that is fully balanced and only has XLR inputs, if you use a converter and go RCA from a Preamp, are you losing out in quality?
Here is something from audioholics and their review of one of their amps -
"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."