On a real record, crackle comes mostly from the surface. Static charge attracts dust into the groove, and tiny, often invisible scratches make the stylus click and pop; Audio-Technica notes that micro-scratches cause most of it and that the shape of the stylus affects how much is heard. Collectors try to minimise it with careful cleaning and handling.
Producers often do the opposite. Crackle is the most prominent sonic marker of lo-fi hip hop, and Adam Scott Neal’s 2022 study describes how today’s tracks add sampled or synthesised dust as a deliberate production choice, sometimes running continuously beneath the music. It may come from a recording of a real record, a plug-in or a sampler effect such as the Vinyl Simulator on Roland’s SP-404MKII. In jazz lo-fi it suggests an imagined, well-loved record collection.