Device for producing chorus effects

Abstract

A device for producing a chorus effect for an electronic musical instrument. The device has two sets of parallel time delay modulating circuits with each set having two circuits therein and the circuits being adapted to have the musical tones from the electronic musical instrument supplied thereto. Saw-tooth wave generators are coupled to the respective time delay modulating circuits for supplying the respective time delay circuits in each set with a saw-tooth modulating wave having a gradually increasing slope and a sharply decreasing slope, the saw-tooth wave supplied to one circuit in the set having the gradual slope increasing in the positive direction and the saw-tooth wave supplied to the other circuit in the set having the gradual slope increasing in the negative direction so that the waves in the set have opposite polarities, and the saw-tooth waves for one set of modulating circuits being 180° out of phase with the saw-tooth waves for the other set of time delay modulating circuits. A plurality of amplitude modulating circuits are provided, one coupled to each of the time delay modulating circuits, and modulating wave generators are coupled to the amplitude modulating circuits for supplying modulating waves to the amplitude modulating circuits for making the output from the respective time delay modulating circuits a minimum when the direction of the saw-tooth waves for the corresponding time delayed modulating circuits is sharply decreasing. Mixing means mixes the outputs of the amplitude modulating circuits.