The Fulltone Ultimate Octave (UO) is a guitar effect pedal that combines a monophonic sub-octave generator with a distinct fuzz circuit. Unlike digital pitch shifters, the UO utilizes an analog frequency divider to generate a note one octave below the input. The design is widely considered a modernization of the Tycobrahe Octavia and Univox Super-Fuzz, but with improved tracking, a dedicated blend knob, and a versatile fuzz section. The schematic reveals a hybrid approach: precision analog dividing combined with germanium or silicon clipping stages depending on the specific revision.