When i have my gibson les paul and i can play the cords of ZZ top / Just got paid / under pressure for example , i ll record it on the studer / telefunken .
To see/ hear whats left of it
No more so than traditional transistor stuff. More of this has to do with the design rather than the actual parts!
If the feedback is insufficient, it will add distortion of its own (mostly higher ordered harmonics thru bifurcation). This is why most solid state amps are bright. If you are able to add enough feedback the brightness goes away. That's a lot of feedback! Most amps made in the last 70 years or so simply don't have enough. That is at the heart of the tubes/transistors thing.
Distortion is an interesting phenomena in how the ear converts it into a tonality. Equalizers OTOH actually change the frequency response. But the ear can treat the two in very much the same way. There seems to be a tipping point where tonality induced by distortion is favored over actual frequency response.
Proponents of transistors don't like to admit how much they have to be manipulated in order to properly reproduce music. That is why the better ones (amps) are these huge mammoths.
The output impedance of a good number of tube amps is low enough that they can operate as a voltage source with many speakers so with them this is a non-issue. There are also a good number of speakers these days that are meant for tube amps that don't have a low output impedance. So tubes don't have to be a cause for frequency response error.
Ralph, i am happy that you are one of the few manunfacturers that openly and honestly discuss amplifier's true nature (positive and negative as compromises are inevitable in any design may it be transistor or tube) !
It would be nice if others would follow !
There is no magic involved in electronics ! Sure there are different aproaches and by chance sometimes you hit a sweet spot in bias settings of a specific tube (this by the way can explain why we love tube rolling, not because the tubes are different but the bias settings change, but that is for an other thread maybe).