A purely balanced application -in proper use and context- can bring some sonic changes to the table.
a bad thing: In balanced, real balanced... the transients are made up of two separate amplifiers moving in opposite directions, that creates the transient, each done piecemeal, and put together into a paired whole.
Not all transients are the same, ie the reality of the chaos of music in all it’s infinite facets. Electrically, in build terms, it looks like nearly unpredictable chaos.
thus we hear ’new stuff’ in the music when we go balanced. Part of it may be for good reasons, as two may work better than one. less stressed, less distortions as they are working each at half capacity, re their ability to correctly delineate high speed changes. That is all fine and good. ie, each amp reproduces only half the speed of change required, as they do the single thing, together.
but.
Truth be known, some of that new stuff heard is the distortions that occur when two amps, moving in opposite directions, try to delineate a transient and micro transient. We get twice the transient speed capacity as they are ’moving away ’ from one another at their normal speed or capacity for speed of change. That is the advantage to a truly balanced system, re transient delineation. Each is working only half as hard, in the area where they distort the most, ie transients, or the highest speed of change in electrical value possible for the circuit.
but the drawback is that it is being re-created by two distinctly separate amplifiers, like two people walking away from one another to delineate the size of the space between them. it can be done twice as fast, or with a capacity to do things twice as fast re the size of the space between them.
problem is that it is supposed to be one reliable, perfectly delineated in behavior space, each time under all possible conditions.. but it’s done by two distinctly different people (even if twin like!) so it will never be truly properly delineated. distortions in motion will be there. Inescapably so.
With the amplifiers, it happens in the transients, and the ear works and hears ONLY the transient for 100% of what it hears, so we WILL hear those micro differential distortions, even if measurement weighting criteria says it is vanishingly small.
Engineering does not weigh (the meaningful bits it assigns value to) it’s analysis in the same way our ear does, so the method and the logic of the analysis, in engineering term, as compared to how the ear weighs the whole signal... is INVALID. this is how we hear ultra tiny differentials, when engineering says the differences are vanishingly small. The two components (ear vs engineering measurements) have almost zero meaningful relative relevance to one another. this is why the audiophile argument persists for decades upon decades. the question and the answer have very little relevance to one another.
Or, the longer a problem persists... the more fundamental the error in the formulation of the question. I’ve personally been working with the correct weighting in this, for over 30 years. but it really does not go anywhere when the rest of the system is not thinking that way. One ends up being dismissed as a kook, even if they’ve been right the whole time. That’s the way bell curves related to the masses- works.
Point is, balanced amplifiers simply present a NEW to your ear different distortion pattern of/in the transients, and transients are all you ear hears, so we hear it, as it represents 100% of what we hear.
A single ended amplifier does not have this two step or two stage transient delineation and may sound MUCH more homogeneous and correct to some or many ears, as compared to a differential amplifier, ie a true balanced amplifier.
Some might even say that the new distortion pattern might be realized by some as being better detail, when in fact it is just a new distortion pattern occurring in the most important (only) area we hear via. It is cleaner, yes, but it is also a new semi-random harmonically and complex loading related distortion pattern at the same time.
A mere difference in when listening to balanced vs single ended is not some form of correctness, it is merely a difference noted. This can show something to us but it is indeterminate if it is the correct thing. Noggin power needs be applied.
in most cases I’ve heard, it is not cleanly and totally (as whole analysis may go) the correct thing as to what is heard in balanced. to me it sounds cleaner but it is at the same time a dirty obscuring fuzz that I have to try and listen through. It’s great for trying to mix audio but that is not how the music actually sounds.
for example.. with balanced transistor amplifiers, we get double the transistor noise added to the transients, as we’ve got two circuits trying to do the single thing, as compared to the single ended amplifier. With class D, it is far, far worse, in multiple ways, and can lead to people thinking it is revealing detail when it is is actually detail obscured by high levels of micro-transient semi-random harmonic noise posing as detail. That’s mess - I won’t get into here. I’ve done considerable levels of single cause analysis in all of this and it is quite clear to me.
Since it involves human ears and it is not calculable as a hard number as ears are personal, engineering (in it’s limited scope of foolishness) dismisses what we hear and relies on badly interpreted and badly thought out numbers, alone. Such blinkered madness....(which leads to the problem with places like ASR, which can be like a Circle Jrk, where everyone thinks they are coming from the right direction, and confidence in that is brought about by others thinking the same. The human body as a carrier of intellect can be quite damaging to logic and fundamentals in logic. Physician - heal thyself)
Since we each weigh and build out our individual bits of human hearing differently, one has to figure out if it is ’true’ for themselves, individually.
But the tale or story about the distortions encountered in balanced vs single ended and what it means to the ear --- is definitely true.
Ie, that balanced ain’t all goodness, it is half bad, and half bad in the most critical area for the human ear and how it works.
Single ended ain’t all goodness, but it is goodness in some fundamental ways, with regard to how the ear works.
The Truth We Dare Not Face, by Divine Electronics ('tis fitting):