SEM diamond stylus travelling through LP grooves (H100/0086) Hoodie

Scanning electron micrograph of a diamond stylus travelling through the grooves of a long-playing, stereo record. The grooves are cut into a flat disc of polyvinyl chloride. The groove varies with the intensity of the music: the straighter the groove the quieter the music, the wavier the groove (as here) the louder the music. The stylus picks up the music modulation from the sloping sides & transmits it to the cartridge, where a piezoelectric crystal or an electromagnet converts the vibration into an electrical signal. Although thoroughly cleaned, this needle is encrusted with dirt. Magnification: x30 at 35mm size, x220 at 8x10-inch size. Reference: MICROCOSMOS, figure 9.16, page 182.