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

Let me ask a simple question of anyone reading this post. This might lead to an understanding of what I'm talking about. It also may pull your thinking slightly outside the box.

Do you know what part or area of a circuit determines the signal to noise ratio of the circuit?

Please refrain from wise guy answers. Thank you.

As I understand it Roger, you have a means of detecting this 'velocity' but what I found peculiar last time I engaged in this topic was that you had not quantified this velocity as a specification. I'm pretty sure you're not talking about risetime/slew rate.

The question is, have you quantified this circuit operation with a spec? Or put another way, have you quantified the 'velocity' spec?

At least you confirmed one thing- that you are not talking about risetime/slew rate.

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?