Abstract: An interface circuit for converting analog signals from a musical instrument and/or a microphone to digital pulse signals for use with electronic music synthesizers and the like includes an input amplifier for receiving analog signals from a musical instrument and/or a microphone. A precision rectifier is coupled to the input amplifier for generating full-wave rectified analog signals. A strictly digital output circuit is connected to the rectifier for generating a strictly digital pulse signal. A quasi-digital output circuit is connected to the rectifier for generating a quasi-digital pulse signal in synchronism with the strictly digital pulse signal. The digital pulse signal from the digital output circuit and the quasi-digital pulse signal from the quasi-digital output circuit are adapted to drive a music synthesizer.