The brainchild of legendary effects designer Howard Davis (progenitor of many classic Electro-Harmonix creations) and Pigtronix's David Koltai, the Rototron is an all-analog effect that combines frequency modulation, phase shifting, tremolo, bucket-brigade chorusing and a three-way crossover to achieve that illusive, magical Doppler effect that's at the heart of the rotary speaker sound. In addition to stereo outs (which can create a stereo effect from a mono input) there are dual inputs to receive signals from preceding stereo effects, plus connections for a remote Brake footswitch and expression pedals for remote control of both High and Low rotors.
Hunter, Dave; Ross, Michael (2014) Hermida Dover Drive / Pigtronix Rototron Analog Rotary Speaker Simulator. In: Guitar Player, Vol. 48, No. 10, pp. 126. Available at https://openmusiclibrary.org/article/765338/.