Digital simulation of phonograph tracking distortion

doctorcilantro

Very interesting article by Richard Tollerton on on Digital simulation of phonograph tracking distortion.

ABSTRACT

Phonograph tracking distortion results from the misalignment of a playback cartridge with respect to the cutting head. While it has been researched for decades, it remains a source of mystery: it has never been accurately isolated or simulated. A simulation of horizontal and vertical tracking distortion of extremely high quality is presented, operating on the principle of phase modulation of PCM digital audio, allowing tracking distortion to be evaluated, in isolation, with real musical content. In this context, tracking distortion is equivalent to digital audio sampling jitter, with the jitter spectrum equal to the signal spectrum. Implications of this connection, as well as simulation accuracy, preliminary listening test results, and potential applications are discussed.