Neutral electronics are a farce...

atmosphere

^^ of course, there is the issue of what is meant by 'zero distortion'.

I think it narrows down to obviously having ultra low or no harmonic distortion but more importantly it has to have the absence of dynamic phase errors that fall far below harmonic distortion measurements.

Take for example ground loops and grounding in general.
If you cue up your cartridge with the volume up and listen for noise (hum buzz etc.) it it is dead quite, it does not mean that you do not have a problem with ground loops. The problem caused by some ground loops show up when the music is playing. This is where electromagnetic broadcasts such as current running through your speaker cables can be picked up by a low Z loop that includes your IC's.

The other problem is extremely low level hum (not audible) that is contaminating the phase angles of bass info between 60 to 120 hz.
It dynamically modulates the presented image like a shake table. As a result, the velocity of the sound waves is modulated and the total presentation is perceived as a smear or out of focus.

Amplifier errors in the area of phase distortion must be removed first..
Harmonic distortion only happens when the phase distortion is unchecked.
If you kill the phase errors you kill harmonic distortion.

That's zero distortion.

Roger

"^^ of course, there is the issue of what is meant by 'zero distortion'."

That's true and there is another related issue concerning whether "live" can actually be undistorted.  

geoffkait

Would you settle for whatever distortion you get in the concert hall during a live performance?

Its nothing but air which is a linear transfer medium.

If it did exactly the same thing in your home would you say "this is just like being there"? If not then some kind of distortion is happening at home and the alternative medium [electrical] transfer of sound waves does not match the purity of air.

It is a simple concept. Make the electronics act like air.
It requires that you match the velocity of air which is zero with no wind.
The sound waves velocity riding on top of a zero velocity (air)  results in a single un-modulated constant speed of Mach One (about 750 mph)
When that happens you will not be able to tell them apart.

If music is traveling toward you in the hall at 750 mph why would you not want it to hit you in your living room at 750 mph? That is your proof that it is live.

If it deviates even a little (747 mph - 753 mph)  it becomes a red flag to your brain and tells you it is not live.

This is no longer a theory.

Roger

If you kill the phase errors you kill harmonic distortion.

Hm. That's good work if you can get it.
https://en.wikipedia.org/wiki/Phase_distortion
In a nutshell though such is not the case, you have have harmonic distortion while at the same time having little or no phase distortion. They are not mutually exclusive.

The difference is one is static phase error and one is dynamic phase error.
I am referring to dynamic phase error caused by the amplifying process.

If you have a dynamic speaker with tweeter, mid and bass drivers and they are time aligned (distance from you ear and delivering a coherent sound)  and you add a shim under the back of the speaker stands so they are now tilted down slightly - you would still be able to hear the music but the coherency will be off by the same amount all the time. this is due to the physical maneuvering of the cabinets (mis-aligned). The tweeter is now somewhat closer to you and so the highs will now arrive too soon.
This is an example of a static phase error. if you had someone take your speakers and rocked them back and forth while you were listening - that would be dynamic phase errors. It is a process of modulation not tilt.

A tilted speaker still gives you a view of the soundstage (but from slightly different view)

A modulated speaker cabinet will cause the sounstage to blurr like a shake table. Under those conditions it is difficult to nail down where everything is.

Bottom line - even with perfect bolted down loudspeakers with good coherency they cannot project a stable image due to the dynamic modulation of the velocity fed to the speakers by an unstable amplifier.

90% of all system problems are from the electronic amplifiers.
10% is all the cables, power cords and magic pebbles.

Phase modulation is gross amounts of distortion since your entire perception of a live soundstage depends on objects not shifting around during the playback process. (like someone shaking you speakers)

It is literally the same thing as a photograph taken out of focus.

Remove the shaky nature of the display and everything is stable and in focus.

That can only happen inside the amplifier circuitry.

Roger