What is the TB-303?
The Roland TB-303 Bass Line is a small silver bass synthesizer with a built-in step sequencer. It was released in 1981 and was a commercial failure, but by the mid-1980s young producers in Chicago had discovered that turning up the resonance and sweeping the filter gave it a squelching sound unlike anything else. That sound became acid house.
303_LINE is an independent fan archive of the machine. You can play a free TB-303 style synth in your browser, read how it went from flop to legend, compare clones, and see what originals cost today. Looking for a "TR-303"? Here is the difference.
Explore
Play the emulator
A free TB-303 style acid synth and 16-step sequencer in your browser. Share your pattern with a link.
Read the history
The 1981 flop that Chicago turned into the sound of acid house.
Compare clones
Behringer TD-3, Roland TB-03, Acidlab Miami and software options.
Check the price
Live asking prices for used originals, and what to check before buying.
See acid on tour
Upcoming shows for the artists who built careers on this machine.
Learn the words
Resonance, slide, accent, cutoff: the acid vocabulary in plain language.