Balanced vs Unbalanced?

No tubes, no noise when I put my ear up to my speakers. I see reason to complicate things by adding a bunch of extra stuff in order to improve things.

Ditto.

There is no fundamental difference in sound quality between "balanced" and "single-ended" circuits. The major upside to balanced circuits is that they are less susceptible to correlated noise picked up by interconnects, ground loops and power supplies since the balanced circuit floats inside its own insulated world.

Agreed.

I would add that balanced usually has a higher signal level (pro audio).

I would add that ground loops are quite often a problem if you talk about audiophile quality with recordings that have tremendous dynamic range. However for your average Green Day of Red Hot Chilli Peppers hyper-compressed releases there is unlikely to be any audible difference between RCA and balanced.

One question about balanced and amplifiers. I know sources and preamps need to have true balanced topology to make use of balanced's advantages. Is this true when the signal reaches its final stage of electronics - the amplifier? Or is this where the balanced signal is ultimately converted to a simpler signal to drive the speakers? How does balanced work in an amplifier? IE - compared to amplifiers that have XLR in but don't employ true balanced?

I have amps that have been reported to run best in balanced mode, but I couldn't really hear a difference. These days my preamp (Herron VTSP-3A)does not have balanced outs so it is not even a possibility. With that said, I don't care, my preamp is the best one I have ever had and my system and I don't see not being able to run in balanced mode for my amp as a big deal as it sounds darn good to my ears the way things are.

My amps have not only separate connections but separate curcuits for rca's and XlR. You have to switch curcuits when changing between the two and the paperwork says that the amp must be turned off.