Balanced / single ended night and day difference

Just for kicks I connected the balanced and unbalanced outputs of my universal player (Marantz ud9004) to an unbalanced and balanced input on my multi channel analog preamp (Theta Six Shooter). I then ran the single ended output through the (single ended only) HT bypass of my 2 channel preamp, so the signal was never fully balanced end to end. Expecting little difference I was in for a shock. Completely different sounding. In a nutshell, RCA is more "dispersed" wider sonudstage, while balanced is more focused (especially vocals are dead in the middle between the mains), I guess better imaging in audiophile speak. Anyone had similar experience? How can this be?