Running balanced. Difference between XLR vs. RCA.

I've purchased a pair of Simaudio W-10 mono blocks and P-5 preamp. The manufacturer suggests either interconnects, XLR or RCA, for balanced operation. From the little amount I know of balanced operation... it takes both signals (+ and -) and only amplifies the difference of what is 180 degrees out of phase? Thereby cancelling any added noise? Can it do this with RCA? The manufacturer says if you aren't running in a balanced mode then use only the + input with RCA, and cap the un-used - input, as long as your preamp doesn't invert the signal. If running balanced mode with RCA then use + and -. Of course it does have XLR capabilities also. I contacted Simaudio on this with no recommendations, just some suggested cables. Wanted to get some info from the Audiogoner's experts, and then audition some cables, and let my ears make the final conclusion. Thanks for the responses.

their literature is a little misleading, you will need a balanced xlr cable to us the amp in balanced mode as they are designed for. Just get any cable you like or even a generic pro cable like a Canare or Belden based one and enjoy those amps!

steve

I'm not certain that posts here are directed at my comments about "true balanced." To clarify, pasted below are manufacturers comments that explain the issue I have in mind.

Balanced or TRUE balanced?
"Quite a few high end audio manufacturers have built their amp and preamp circuits around single ended designs (not balanced). When the balanced craze began, they all wanted to jump on the bandwagon, so they did a quick fix to make their single ended circuits balanced. They simply added an extra input (for the 3d wire) which created a balanced input (because it has CMR), but not a balanced circuit.

So, when you hear the term 'true balanced,' it usually means that not only is the input balanced, but so too is the entire circuit."

I recently converted my long time ICs to balanced operation. Other than the increased gain noted above, the sound was the same. IMO, if you have a noise/RF problem, and 'true balanced' equipment,then balanced cables should be explored. Otherwise, relax and enjoy your SE
gear.

If SE CKT, using RCA or XLR IC would make difference. But for balanced CKT, XLR will benefit from more gain, CMRR, .... CMRR is more the power supply related, a better power supply will help also. Lower RF noise will help both SE and BL, but not make SE the same as BL.