Abstract: Apparatus and method for sampling analog signals during successive time periods, the sampling signals being essentially aperiodic. The interval between sampling pulses is selected pseudo-randomly. A circuit for producing essentially aperiodic sampling signals gates a periodic signal through a number of delay means, each having a delay time that is a small fraction of each period, the number of delay means being selected by pseudo-random signals. Periodicity of quantization errors is broken up, thereby reducing concomitant unwanted harmonics of the sampling frequency that are introduced when the sampling signals occur at equal time intervals.