I am finishing up my testing of a borrowed Noble and getting ready to send it back. I have it in the FX loop of a PJB Super Flightcase amp after an Fdeck HPF, which is where it seems best. On the fence about whether to order one, but leaning toward it because it seems I would not have any trouble selling it if I decided I didn't want to keep it. Please let me know if I am wrong about this part!
I played several concerts and a small house gig with it and it sounded good, but at the time I had not yet found the "sweet spot" for how to set it and I think it could have sounded a lot better. And truthfully, the sound I have been getting with the Sansamp Para Driver DI in the same spot in the chain has also been excellent. The difference, for me, is that the Noble is simpler, and than the Volume knob doesn't seem to do all that much to change the tone, whereas on the Para Driver it changes the tone every time you move it. If I am wrong about this, please let me know - but I kind of like using the Noble between the input stage (where I can set the level to just before clipping) and power amp, cutting the low bass I don't like and then using the volume control to get maximum makeup volume that I can see on the limiter light; this gives me much more volume and "heft", for lack of a better word, with the master volume on the PJB set lower than before, and without necessarily making the signal too hot sounding.
The sweet spot on the EQ for DB seems to be bass all the way counter clockwise and treble at about 9 o'clock, which gives a little bit of nice definition to the sound. If I am understanding what the tube preamp is doing in conceptual terms, it would be something like emphasizing the upper partials of the overtone series rather than the fundamental. Is that in the ballpark?