Algorithms for modeling nonlinear geometric distortion of vinyl records [Abstract]

Abstract

Classical vinyl records have a characteristic sound that is distinct from an ideal digital system and is often described as warm, mellow, or "analog". Responsible for this sound is the sum of linear and nonlinear distortions which occur during recording and playback of the record. The distortions are due to mechanical and electrical nonlinearities. One main source of nonlinear distortion lies in the discrepancy between the cutter's shape and that of the playback stylus: The cutter is a sharp tool while the playback stylus has a ball?like shape to distribute the tracking force over a wider area. This leads to a slightly different movement of the playback stylus in comparison to the recorded groove, yielding so called "geometric distortions". The mechanical, i.e., geometrical nature of this phenomenon, makes it possible to find accurate mathematical descriptions. This approach was used to develop a model for the real?time simulation of the typical sound of a vinyl record. The developed tool allows the simulation of the "vinyl sound2 and can basically be used to create and control a wide range of nonlinear distortion which can vary from a slight enhancement of a given signal to new effects of sound design.