10 August 2009

Digital Simulation of Phonograph Tracking Distortion

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 cannot be isolated, it has not been accurately simulated, and its importance remains undecided. Here, a PCM simulation of horizontal and vertical tracking distortion of extremely high quality is presented, operating on the principle of phase modulation, 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.

127th AES Convention, New York; Poster Session P14 (Signal Processing). Currently scheduled for Sunday 11 October at 10am. Date/time possibly subject to change.

Getting this paper out the door has been the predominant reason for the recent dearth of activity on this blog. More info will follow here, including a downloadable simulator implementation, the samples used for the existing listening tests, and an open invitation for a new listening test.