High Quality Interconnects for Luxman L-590AXII

I would like to seek experiences from current owners of the Luxman L-590AXII (or other Luxman models). Have you tried different interconnects particularly the balanced XLR versions and heard a profound difference with the cables? I only compared a $1,500 balanced XLR to a $500 single-ended RCA and so far the balanced XLR sounded superior. I believe the balanced connection of the Luxman is capable of producing better results when compared to single-ended.

Has anyone compared different balanced interconnects on the Luxman and noticed a difference in sound quality between the cables?