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

The problem with most DACs is not the chipset on the front-end.
It is the analog stage that follows. The digital data to be converted to analog far out strips the ability of the analog section to pass along the stored image.

" the preamp itself isn't really improving "
This was true up until now.

The digital data to be converted to analog far out strips the ability of the analog section to pass along the stored image.

This statement is false.

My point was that unless you attach a distortion-less analog stage to the back end, the full resolution cannot be realized.

I can run a 16 bit dac that will out perform a 24 bit dac simply be using a distortion free (0%) analog stage.

In a DAC the analog stage is the weak link.

I'm assuming that you have used tube output stages and recognized the difference in sound quality.

^^The premise of the post above is false.

Try running an analog source through that output stage and you will see why.

As a bit of a tip: its probably not a good idea to talk about 'distortion-less' in the way that you do, it strains credulity.

hi @ roger_paul
I guess the loss of distortion has become a single minded pursuit for many amp maker - HAlcro; Neodio; LAvardin - do they not address 'velocity' already?
It is fascinating that single ended amps and valves - particularly OTL designs have such legions of fans and they major on the reproduction of a live sound.