I have a Dr Z Maz 38 that Im thinking about putting a negative feedback loop in for some more clean headroom. I have always heard it will clean it up. I read on Z's page that the Mazerati he added global feedback to give it alittle more clean headroom. it is my understanding the first Maz 38 had feedback. anyone ever done this to one of their amps that had no feedback, and after the fact how did it sound?