|Cultural origins||Late 1980s – early 1990s, Germany, United States, and United Kingdom|
Acid techno (also sometimes known as just "acid") is a genre of techno that developed out of late 1980s Chicago acid house, particularly its "squelching" synthesizer sound obtained by using very distinctive instruments created mainly by Roland, such as the SH-101 and TB-303 for bass and lead sounds, and the TR-707, TR-808, and TR-909 for percussion. Acid specifically refers to the use of the 303, or any other synthesizer designed to emulate its unique sound. While modern electronic instruments have memory banks of different sounds or patches, these machines had to be manually set by adjusting control knobs. The acid sound is achieved obtained by either setting the controls to extreme parameters, or manipulating them in real-time as the track was being recorded, a technique known as tweaking.