Voice synthesiser filter for generators - has continuously variable function analogue section followed by synchronised numerical filter

摘要

The filter is for generators providing electrical and audio outputs the modulation of which is analogous to the human voice. The filter allows modification of the spectrum at acoustic frequencies and has a variable transfer coefficient characteristic. An input analogue filter (1) is continuously variable and reversible and is controlled from potentiometers (3). A following numeric filter (4) has a clock (6) controlled function sampling facility, the clock pulse frequency being regulated by internal and external potentiometers. Both control systems are synchronised such that the output signal, when made acoustic, reproduces the modulation required.