A method for analyzing sampling jitter in audio equipment

A method for analyzing sampling jitter in audio equipment is proposed. The method is based on the time-domain analysis where the time fluctuations of zero-crossing points in recorded sinusoidal waves are employed to characterize jitter. This method enables the separate evaluation of jitter in an audio player from those in audio recorders when the same playback signal is simultaneously fed into two audio recorders. Experiments are conducted using commercially available portable devices with a maximum sampling rate of 192~000 samples per second. The results show jitter values of a few tens of picoseconds can be identified in an audio player. Moreover, the proposed method enables the separation of jitter from phase-independent noise utilizing the left and right channels of the audio equipment. As such, this method is applicable for performance evaluation of audio equipment, signal generators, and clock sources.