I am interested in modifying my M200s to accept a differential signal via an XLR cable, instead of the (factory) RCA jack, similar to the mod performed by Underwood HiFi.

I recognize that performing this mod would void the warranty and, depending on the complexity, I may not even attempt it. But, the equipment I'm using upstream of the M200s provides the differential outputs, these outputs provide better noise immunity, and I prefer the reliability of XLRs to RCAs.

Are instructions on how this could be accomplished available on the web somewhere?