Are future improvements in Amp/PreAmps slowing to a crawl?

Yes I am not talking about slew rates like volts/us.

The velocity spec is that the output velocity must = the input velocity.
By default the signal entering the circuit has a horizontal (time domain) velocity of Mach One because the music was captured at that speed.
Unless you maintain this "embedded" velocity you are going to inject small amounts of Doppler into the chain producing an out of focus result.

If you record music on a tape machine at 15 ips you must set the playback speed also at 15 ips. If your tape machine during playback is actually 15.05 ips you will have a slight leaning towards Micky Mouse.
If it is playing back at 14.95 ips it is leaning more towards Barry White.
This degree of deviation does not sound like a lot but to the projected image it is devastating.

Even thought the amplifier has no moving parts and does not seem like it can vary the playback speed - but it does.

It alters the velocity the same as a poor capstan servo. It is the equivalent of wow and flutter.

When the music signal encounters a non-linear event - the delivery speed is altered.

A superposed "hologram" will collapse and every instrument in the performance will have the same degree of focus or lack thereof.

Your analogy of analog tape does not hold water when applied to amplifiers. Amps don't cause pitch variation. Speed variation in analog recorders does.

From your description, if I had to guess its almost as if you are describing the speed of the amplifier in terms of propagation delay- that the delay from input to output must be at the speed of sound.

But I suspect that interpretation is not correct either...

But at any rate you've not answered the original question- which is: have you got a means to quantify this?

Again with all due respect..

"Amps don't cause pitch variation"

This is in fact a false assumption. They can and do cause pitch variation.
This is not something I suspect (as in theory) - it is something I know (as in proof)

I started out years ago with a theory of what was happening in analog amplifiers. Today it is no longer a theory.

The breakthrough has already happened.

I'm really very sorry for coming off as an arrogant "know it all". The facts are on my side. This is one argument that you cannot win.

Its up to me to perhaps provide a better understanding or illustration of what I'm talking about but it is absolutely true that analog amplifiers do vary the pitch.

The reason it has not been known before is because of the amount being so tiny. It is this tiny amount the determines the degree of focus realized in the image.

kosst_amojan,

Thanks for being civil and open minded. I will be happy to fill out your form. You need to give me time to generate the math on a sample of this phenomenon. In fact I was going over some figures that I thought might allow more understanding of the problem found and how my solution is implemented.

BTW - question for you.
" Circuits vary the pitch through intermodulation distortion through summing the fundamental with harmonics."

Where do these harmonics come from exactly?