Thank you Bill, if I remember correctly, C-03 has pseudo-balanced inputs and outputs, while it is internally single ended. This design might have a 'normalizing' effect on C-03, as X-03 output is transformed into single ended no matter what. It might be interested to drive a symmetrically balanced pre that has both XLR and RCA inputs... with X-03 and see what happens.
Saluti,
Guido