The ROSA Overdrive was born from the concept of a drive pedal that emulates playing through a tube-amp, getting pushed and saturated.
Lusithand really focused on the "feel" for the ROSA and how effortless it feels to play through it, either if you are playing softly, with your fingers at lower gain settings, or if you are digging in with a pick at higher gain settings (this pedal loves a PBass for that rock sound).
Go from fairly clean to well saturated (almost fuzz like) from one end of the Drive knob, to the other. The bottom end is big on this one!
CL switch: This inserts a good amount of the clean signal into the mix. This is essential to get a cleaner sound at lower gain settings (there is always some grittiness on the regular tone) or to add definition and an amp-like-tone at higher gains.
HOT switch: Change the voicing of the Drive channel; down for cleaner and up for hotter and thicker.
HI switch: Extends the higher frequencies for the driven signal.
VOL knob: Controls the overall volume of the pedal.
EQZ knob: A Tilt Equalizer allows to gently (and musically) compensate for different sounding instruments.
DRIVE knob: Go from slightly saturated to overly saturated and listen to your signal compress more as it gets dirtier, while maintaining some dynamics. (The Magic Control!)