Balanced circuits and break-in

Both my preamp and CD player are fully balanced designs. That said, I am running (and have always run) them single-ended using RCA interconnects.

Question #1: Assuming both are new components and thus have only been run single-ended, is one "side" of the circuit literally not being used and is not passing signal? I have read comments to that effect, but perhaps I misunderstood.

Question #2: The first question put slightly differently, if I all of the sudden start using such equipment in balanced mode, does the theretofore unused half of the circuit have to break in like any new component?

These questions arise because I am thinking of switching out my single-ended interconnects for balanced interconnects (I did not already do so long ago because I spent a lot of money on my single-ended interconnects, and will take a bath on them if I sell them), but wonder whether the components will then have to break in all over again when they are finally run in balanced mode.

Thank you.
The answer to both your questions is yes. But the majority of your breakin in is behind you. You'll probably find the sound opens up fairly quickly as your not waiting on all the circuts to settle, however, that said you will of course have to break in the new cables, which is always fun (not). However, my experience in switching over to a balanced run from SE RCA was very worthwhile. I found running balanced did a few nice things. 1) Lowered the noise floor which increaced the dynamics. 2) Bass response was much better. and 3) the soundstage became wider and deeper, and floated a better central image. Good listening!-Ken