Balanced vs Unbalanced?

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!

How does balanced work in an amplifier? IE - compared to amplifiers that have XLR in but don't employ true balanced?

A fully balanced amplifier maintains separate signal paths for each of the two input signal polarities, all the way to its output terminals. So the negative or black speaker terminal is not connected to ground as it would be in an unbalanced amplifier, and is actively driven with a signal. The signal is similar to the one on the red speaker terminal, except that it is inverted.

An amplifier that is unbalanced/single-ended internally but has a balanced (xlr) input feeds that input into a differential receiver stage that has a single-ended output. That single-ended signal is fed into the rest of the amplifier circuitry, which is unbalanced.

Re the original question, several advantages (or at least theoretical advantages) of fully balanced design have not yet been mentioned. These include cancellation of some forms of distortion that may otherwise be generated internally; and, particularly in the case of a power amplifier, lower levels of power supply-related noise. There are some others as well. See this Atmasphere white paper.

My feeling is that both single-ended internal design and single-ended interfaces are inherently compromises, assuming equal quality, starting with the fact that in nearly all modern designs that have single-ended interfaces signal returns, circuit ground, chassis ground, and ac safety ground are all common. However, there seems to be ample anecdotal evidence that in most systems and for most people the degree of that compromise is either insignificant or is overshadowed by many other variables, one of which is price.

Regards,
-- Al