Ring modulator synth

Pigtronix Ringmaster is a ring modulator synth designed to create analog harmonizer and tremolo effects that can be made to follow the notes you play. Expanding on the “Intelligent Ring Mod” found in the original Mothership pedal, Ringmaster adds LFO and Sample + Hold modulation sources, pitch following tremolo and well as wave shaping for both inputs to the analog multiplier circuit at the heart of this uniquely musical ring modulator.

https://www.pigtronix.com/pedals/ring-master-analog-multiplier/