Thanks Chris for the extensive review of the Noble. As someone who has been thru a huge amount of amplification gear over the years and now finds a natural diminution in interest (based on having solved the problem adequately) I find that the Tube preamp coupled with a good piezo is the compromise I can live with.
What the tubepre/piezo + the natural acoustic sound of the bass represents is the best, simplest, shared reality between player and audience and I'm glad you focused on that in your review. It is really in the high end information and the taming of the piezo "quack" (...and lack of feedback) that the Tube preamp shines in providing enough realism to allow the player to just get to playing and stop obsessing about the sound.
There are some differences in the way tube sets or circuits, get there, different granularity in the amplification factor, slightly different sound stages etc. but really it comes down to the feedback loop between the player and the nature of the sound entering his/her ear while playing (with other players/simultaneous sounds).
The tube pre I use is similar to the Noble, it uses a different tube set that has it's own characteristics, but the EQ is very similar and what you say about the simplicity of this type EQ is so true: it sounds good gig to gig in a way that stops restless hands from messing with it and you find yourself playing without altering much. Just great.
I love microphones, I really do, they are better, truer, wider, more live and genuine sounding etc. but they fail me time and time again in a live setting, because of the variables that I to overcome to dial it in (if I ever can) whereas the tube preamp gets to emulating that enough and with such ease that my ear is satisfied.
A lot of cats got their feet wet with the Black Box by Brad Sarno and it is a great inexpensive way get into tube preamps, but IMHO the sweetspot is with devices like the Noble and the Sarno V8 and (possibly the Jules Monique.) preamps where you can control the Treble. Controlling the treble knob is where the air is (mostly I spike it and leave it like you).
Anyway nice review, I love that Bird head and have been using the fractal fingering possibilities to come up with different phrasing variations...Bird endures.