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

@roger_paul 
You do know the more you talk the more you sound like you don't know what you're talking about, right? 
A variety of Pass push-pull circuits feature a pot to balance the ground of the input stage. By off balancing it a bit you get a warmer second order and it sounds better, because as pretty much all of us know, near-zero distortion amps sound cold and lifeless. A TON of amplifiers are designed with some ability to manipulate the modes of distortion. Unlike most, I know where mine is and how to do it. What's more, as I previously pointed out, the nature of dimension is distortion so it's reasonable to conclude that well chosen distortion can enhance or reduce that perception. Those of us in the know are well aware of the fact that distortion can be utilized as a tone control to an extent, too. Really good designers understand that carefully chose distortion is much better than no distortion. That, in a nutshell, sums up the entire philosophy of the single ended triode topology. 

"Here is where there is a problem. It is the absolute absence of manipulation that makes it distortion-free. You know like air." 
This is just a lie. Not only can you not furnish a measurement to justify that claim, you can't even provide a theory, circuit diagram, or patent. It's just a lie.
"I can't wrap my head around the idea that we need distortion in our playback systems."
You don't understand how a volume knob works. I'm not at all surprised you don't recognize the usefulness of distortion. 

As for my F5, it uses MOSFETs on the output stage and they're not the most linear devices in the universe. Big power JFETs are 10 times more linear. The F5 uses a good bit of negative feedback to achieve it's specs. Without it the damping factor is weak, the bandwidth is narrower, and the distortion is much higher. Big deal. I'm not ashamed of it. I don't think Nelson is ashamed of it. I don't consider it a bad thing. It's necessary for the voltage gain stage to drive the current gain stage accurately and it's implementation is carefully considered. You see, I recognize the impossibility of the lies you claim and I embrace artfully utilizing shortcomings. I emphasis "artfully" because art is what it is. The opposite of art would be science. And since you deny there's art to this, you must be in the science camp. But you're not really in the science camp because scientists measure things. You're just making it up!

So what now, Roger? You gonna take more of my words out of context to weakly mock them? Just keep running from the fact you've got bogus claims you've been called out on? Keep accusing me of being the measurements freak when it's you claiming perfection with ZERO proof? ZERO circuits. ZERO patents. ZERO actual theory. Your white paper reads like the mombo-jumbo on Geoff's Machina Dynamica snake oil page. It's not a technical piece of work. It lacks what defines a white paper; PROOF of the theory. 

You do realize I know the circuit you are listening to.

Really good designers understand that carefully chose distortion is much better than no distortion.

Not true. If that's what they think then they are not a really good designer.
Something else is happening and they are blaming it on the zero distortion [settings]. They are using distortion as a partial countermeasure to the real issues. I happen to know exactly what the problem is with that circuit but I don't get involved with other designers stuff.

When I said I don't think the designers are thinking outside the box - I was giving them the benefit of the doubt. Unfortunately they just don't know where to look to resolve the issues in their circuits. That's why things seem to have slowed to a crawl. They have run out of things to try.

A circuit can actually measure zero distortion and still not be zero distortion.Typically a sign wave test does nothing but tell how good a low frequency servo it is. Music is an entirely different matter.

kosst,
I'm not accusing you of being the measurements freak. I'm sorry if you got that impression. I'm trying to show the difference between an amp that measures zero compared to an amp that IS zero.One sounds awful and one sounds incredible. Can you tell me how to measure zero distortion with a music signal as the source?

If you measure the voltage level (of the source) like an orchestra playing normally and you get X amount. (lets say 1/2 volt nominal) Then without changing a beat - add the guy with the triangle at the back of the hall when he adds a single note to the mix. Besides not being able to identify it on a scope - how much additional voltage appears now that the triangle is playing. How big is just the triangle voltage? Millivolts? microvolts? nanovolts? picovolts? This is the range of signals I work with and have mastered control over.

If the entire orchestra was quiet and just left the triangle - it would be seen on a scope as closer to the noise floor. In order to successfully project that object back to the rear of the hall and keep it in focus - you need circuitry with enough sensitivity and resolution to handle the task of rendering that object at that distance. The greater the depth or distance of an object - the harder it is to place it back into the image unscathed.

Pseudo-techno-babble. And you sure don't talk like you're familiar with the F5. You don't talk like you're familiar with electronics or physics. 
You're triangle comparison is silly. Sure, if you're silly enough to try to find it on a scope viewing the entire wave you'll probably never notice it. You brag you work in values of picovolts, but you can't prove it. You can't show me a circuit that does what you claim. You can't because it doesn't exist. If it existed you'd have patented it. But you can't patent imaginary things.