Balanced vs Unbalanced?

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.

The pro and cons:

Balanced circuits only has an advantage if used as intended.

If the black box is truly balanced in designed circuitry, from source through final speaker out, then yes it should sound sonically quieter and better matched.

Cable design of a properly made single ended is three cables plus,common and shield. The common shares the path with the right and left negative part pf the circuit.

Cable design of a properly made balanced is four cables plus and negative on left and plus and negative on right which in return each conductor creates it own path and separation as intended.

When a company builds and manufactures a truly balanced source,pre-amp or a amp in practice the final outputs are two separate amp stages left and right that will be a true balanced design. Opposed to one that shares the left/right of the single ended circuit.

In theory and thought one would achieve balanced separation.

1) Less chances of phase shift

2) Higher gain

3) Less floor noise

4) Better and tighter connection with less chance of degregation.

Down size it is costly and debatable. A poorly designed balanced black box will sound less pleasing than a properly designed single ended circuit. Bottom line be aware and research carefully the company that so call design a truly balance components.

Enjoy music!