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

Ok teo... Sounds to me like all you've got is the most long winded way of saying there aren't anymore real breakthroughs and Nelson is right. 

So, I imagine someone is thinking, well, what’s an example of a psychological issue related to human perception of hearing, you know, something consciously or consciously that affects how you perceive the sound? You need to look no further than the standard, tried and true naysayer arguments - the placebo effect and expectation bias. These are both psychological effects, not physiological effects. I believe they are both real phenomena and both affect the sound, presumably for the better. Alas, while they are examples of psychological influences on the sound, they are not really examples of what I am referring to when I mention mind-matter interaction and Morphic fields. Wait’ll the naysayers get a load of this. 😀

Geoff--finally something on which I think I can sort of at least partially agree with you, although the distinction between the purely psychological and the physiological is getting blurred as more folks monkey with brains.

Has a mood affected hearing/perception?  Has anyone had auditory hallucinations--"natural" or, ahem, induced?  Synesthesia?  Ever said, "Hey, did you say something?" when the he/she hadn't made a peep?  "Hear" more deeply into the music, when relaxed with a clear head?  Had a great day and the birds chirped more loudly?  Been irritable and every little annoying noise that's usually tuned out now heard.

Not just hearing...every sense can be impacted in similar ways.  Some of it is hormonal, too.

What's this have to do with amps/preamps?  Depends.

I’m pretty sure morphic fields were laid by the wayside years ago. Sheldrake had great ideas, but the details didn’t seem to pan out..

Teo - absolute objectivity has been dead for almost 100 years. But the mass of humanity will not believe this because it doesn’t match the world they experience. Not until we are consciously involved in the creation of our existence will people ’believe’ it.

Interesting thought, it basically wrong and right.  Yes, the circuit topologies commonly used are reaching a limit in refinement. No, there are other topologies that we are just exploring that are proving better.  I and others have heard them, some now posses products based on these new topologies.  They are groundbreaking but they are a new wave of doing things in a world habituated to the old way.

But only time will tell, and it is telling as listeners discover it.

Barry Thornton