XLR or RCA?

Dear audiogon community,

It was recommended, in another post, that I try a difference IC cable. I was considering the audio quest columbia XLR. ( I am currently using xlr cable between by c2300 preamp and mc275 amp). However, I then read that xlr cables only provide a real benefit if you are using balanced cables throughout your entire system, which I presume means from my turntable into my preamp. Is this true? Because if it is, perhaps I should switch to RCA. That is, my tonearm cable ends with RCS cables. In fact, my pre-amp does not have xlr inputs for phono (though it has them for everything else).

I plead with you, the wise audition community, to lead me out of this mystery!