Question About Amp Hook Ups

I am currently listening to a Krell 400cx amp and using balanced cables from my preamp. I am going to audition an Edge NL-10 amp later this week and have just found out that it only takes RCA ended cables. Can anyone tell me why a manufacturer would make this choice. Is there any sonic benefit? I was under the impression that balanced cables were better than RCA ended cables, especially to the amp. But what do I know if a top company such as Edge would use RCA ended cables only.

Any advice or opinions would be most appreciated.
I also have Krell . Sound better with XLR input. If you using RCA you will have a pin from Krell ( OR DIY) insert to XLR to avoid noise
There was a long thread on this titled "balanced is inherently flawed"... Here's a link I think will get you there:
Balanced cables do reject common mode RFI hum etc, but that's only part of the story. The Krell has balanced circuits which means each channel has mirror image circuitry that drive the signal either positive or negative. Single ended components are cheaper because they contain only half the parts (nominally).

It would be a pitty to pay for a nice Krell and drive it with something single ended. However Pre amps like the CJ 17 and ART are only single ended and great preamps. So the balanced prejudice is like any other, only sometimes true.
My system is truly balanced from source to pre to amp and I believe very stongly in it, however let your ears decide.