NAMM '14 - Mad Professor Old School 20RT & Simble Overdrive Demos Rich OsweilerMarch 7, 2014VideoThe Finnish tone tweaker shows off a new reverb- and tremolo-equipped combo along with a new OD box.tremologearvideosmad-professorgear-show-demonamm-2014tube-combooverdriveeffectsreverbwhats-newGearEffectsVideosNAMMReviews