Just a repport on this unit after using it stock for a while.
This is trully great piece. It's kind of a tone box. Two plate voltage modes produce very different harmonic content. Low plate voltage sounds great on DI bass, clean DI guitars, especialy if they are going through some speaker simulator or amp afterwards.
Can be used to crush stereo room mics, or what ever stereo source that would benefit from SansAmp kind of treatment.
High voltage mode can be overdriven too, and creates different harmonic content (measured with scope and generator).
In the past i was using some tube pres, like Blue Robbie, La610, and i was missing that high amount of tube harmonic distortion when i wanted to go crazy for what ever reason... Even though they are tube, they are for the most part clean pres.
This box can get both really dirty, and clean in high plate mode if gain is backed off.
Variable impedance is very cool on ribbons, dynamics, and transformer coupled tube mics. Doesn't do much on modern high output condensers.