Wow, thanks steelyad! I had thought it was like a saturation control for a preamp gain stage (similar to how the AxeFx 2 has a preamp saturation switch and level control). That is a great tip. I figured Kazrog would have this covered somehow. Time to give that a deeper look. I know I had been critical of the interface stuff on Thermionik in the past but, man, I am getting some great sounds with it of late. It is really climbing up my list of favorite amp sims rapidly and I'm sure this info will help me out even more.