AQUA 303 Acid Bass & Drum Machine

AQUA 303 is a free acid bassline synthesizer and drum machine that runs right in your browser. No download, no install, no sign-up. Click START and play.

It comes wrapped in a Y2K / Frutiger Aero look: glass, bubbles, brushed aluminium and glossy keys, with hands-on knobs you can actually turn.

THE BASSLINE

Resonant filter with Cut Off, Resonance, Env Mod and Decay. Accent, Slide (glide into the next note) and Sustain. Saw or square oscillator, Tuning and Drive. Ping-pong Delay (1/8 dotted, 1/8, 1/4, 1/16) and a small Reverb. 16-step sequencer with a note keyboard: pick a step, press a note, and it moves on to the next one.

THE RHYTHM BOX

11 voices: bass drum, snare, three toms, rim shot, clap, closed and open hi-hat, crash and ride. Per-voice knobs (tune, attack, decay, tone, snappy, level) and a Total Accent. 5 drum kits: 909, 808, Electro, Lo-Fi and Aqua Pop. 8 ready-made patterns (A to H) with bass, drums, kit and settings. Accent track, shuffle, tempo and mute per instrument.

ALSO

REC records what you hear, SHARE copies a link to your pattern, and your work is saved in your browser automatically. Play the bass with your computer keyboard: A W S E D F T G Y H U J K (Shift = accent). Space = start / stop. Double-click any knob to reset it.

TIPS

Turn Resonance up and sweep Cut Off while a pattern plays. Add Accent and Slide on a few steps for that squelchy acid sound.

GOOD TO KNOW

Best on a desktop or laptop with a mouse (it is not made for phones yet). Works in recent Chrome, Edge and Firefox. If you hear nothing, click once on the page first, then press START. Everything is synthesized live with the Web Audio API: there are no samples.

An original instrument inspired by classic analog machines. Not affiliated with any manufacturer.

Made by PaulMX. Code written with the help of an AI assistant (Claude); design, sound and direction by me.

Feedback is very welcome: tell me which sounds you want, which presets are missing and what feels off!