From The Art and Popular Culture Encyclopedia
The Roland TB-303 Bass Line is a synthesizer with built-in sequencer manufactured by the Roland corporation from 1982 to 1984 that had a defining role in the development of contemporary electronic music.
The TB-303 (named for "Transistor Bass") was originally marketed to guitarists for bass accompaniment while practicing alone. Production lasted approximately 18 months, resulting in only 10,000 units. It was not until the mid- to late-1980s that DJs and electronic musicians in Chicago found a use for the machine in the context of the newly developing house music genre.
Phuture's "Acid Tracks" is widely acknowledged to have been the first Acid House recording to incorporate prototypical TB-303 sounds. Earlier recordings featuring the TB-303 can be traced back as far as the early Electro scene, including artists such as Ice T, Newcleus, and Mantronix, as well as pop musicians such as Heaven 17 and Section 25.
In the early 90's, as new Acid styles emerged, the 303 was often overdriven, producing a harsher sound. Examples of this technique include Hardfloor's 1992 EP "Acperience", and Interlect 3000's 1993 EP "Volcano".
The well-known "acid" sound is typically produced by playing a repeating note pattern on the TB-303, while altering the filter's cutoff frequency, resonance, and envelope modulation. The TB-303's accent control modifies a note's volume, filter resonance, and envelope modulation, allowing further variations in timbre. A distortion effect, either by using a guitar effects pedal or overdriving the input of an audio mixer, is commonly used to give the TB-303 a denser, noisier timbre--as the resulting sound is much richer in harmonics.