xlr or rsc i/c's for Luxman D-05

I recently found my D-05 performs much better with Tara Labs RSC Vector 1 RCA i/c's than with cheap balanced i/c's. This seems to be an obvious i/c issue so I'm thinking of upgrading the balanced i/c . I've never believed i/c's make that much difference and I'm still not sure thinking the balanced output of the D-05 may be a more mellow sound. I lack cable access and experience so any advice will be appreciated. I'm looking at the Tara Labs RSC M series, Furutech Evolution II, or Tara Labs ism 2 I've found used.