"AC & RC Boosters are both very dynamic/responsive/musical pedals.
 
The RC booster is very natural sounding. It just kicks "Your Tone" up a notch according to the way you have the gain & volume knobs.  The bass and treble knobs are detented, so if you keep them there (12:00/Flat) your tone goes through uncolored. Aside from being a "Great" clean boost (with gain knob hard left/7:00),  the RC booster also will give you "Sweet/Smooth" sounding overdrive (gain knob hard right/5:00).
 
The AC Booster kinda takes off where the RC booster stops as far as gain is concerned, and gives you a nice range of gain from overdrive to distortion. RC & AC Booster's both have Volume/Gain/Treble/Bass knobs, LED, great soldering work, 9 volt jacks, true bypass switching, and are built like Tanks!!!"

-- Joe Allocco