Basically a lot of us who were earnestly trying to mesh out the standards saw it as you thread-crapping.
Get it now.... shouldn't have used the cheeky emoticons....
On the comparator:
If the argument that tube amps do certain things better than solid-state amps is true, than it seems that a comparator (using solid-state parts or opamps) might not yield any meaningful results.
Why ?
rethorical question as I understand where it comes from.
It comes from the notion/conviction/idea that transistors/opamps can't do what tubes can.
Let's just say I don't share your P.O.V. and see why you will probably not test this way, assuming an opamp cannot capture the effect.
Here is an idea for you to experiment with.
Play music on the tube amp and load with a headphone (or speaker)
record it using a PC (24bit many kHz) and play it back on an amp like the Rag.
Listen if 'the sound' is recorded and captured.
IF it has ... opamps can accurately follow it.
Can't do those tests myself. No access ... no time.
Yes... I also tested a (crappy, not high end) tube amp.
Was interesting to do.
Would like to do this again once with real tube amps.
Not in the business anymore nor access to high-end gear.
What I'd like to see is a method that can capture and present dynamic / transient behavior differences of amps - namely in amount of feedback. Feedback does wonderful things like tighten up the bass and extend FR, but it closes the soundstage and makes everything flatter and duller sounding.
You will need to create a signal that jumps from 0dB to say -70dB (which appears to me my limit when listening to loud extremely resolving speakers)
The signal needs to jump in level exactly around the '0'.
Reproduce it and look with a scope (not a digital recording) and see IF there is overshoot or the signal behaves other than the source.
Easy to see with 2 channnel scope and overlay.
That'll tell you which amp has problems.
Sort of a monotonicity test but with a much larger dynamic difference.
DC shifts will play a role as well, perhaps use a suitable high pass.
Certainly with non-balanced and coupled stages.