The field of transparent dirt boxes is crowded, but how many were based on a film projector? Enter the Walrus Audio 385 Overdrive. Built with the Bell and Howell 385 Filmosound in mind, a projector which guitarists discovered could also be a warm, organic amp, the 385 serves up the standard four-knob configuration of volume, gain, and hi/lo EQ controls to achieve sounds from clean boost to tweed-like breakup.