My lil acid bass

// a 303-style acid bass synth and 32-step sequencer. same sound in three places.

bass.forms = ["vst3 + standalone", "vcv rack 2", "browser"]

bass.price = free; bass.licence = { browser: MIT, vcv: MIT, vst3: AGPL-3.0-or-later }

> download the vst3 > vcv rack module > play it in the browser
I-A1 from the demo set, as step notation: A* - A A^ - A_* A - G~ A - A* - C^ - E~ (* accent, ~ slide)

VST3 in FL Studio

// how-to: download, install, play

Module in VCV Rack 2

// how-to: download, install, play

What it does

Sound

Saw or square oscillator into a resonant 24 dB lowpass, with Tuning, Cutoff, Resonance, Env Mod, Accent, Volume and Tempo (40-300 BPM). Accent boosts level, shortens the filter decay and builds on stacked accents. Slide glides pitch without retriggering.

Sequence

32 patterns (2 banks x A/B x 8), up to 32 steps each, with rest, tie, octave, accent and slide per step. Track mode chains patterns into a song. Load demo set fills six starter lines.

Envelopes

Filter and amp ADSR, and gate length from 10 to 100% (55% matches the original 303).

Same in all three

The VCV module uses the same voice and the same sequencing rules as the web app and the VST3, so a pattern sounds the same everywhere.

Get it

VST3 + standalone

Windows 10/11, 64-bit. FL Studio and other VST3 hosts. AGPL-3.0-or-later (built on JUCE).

My lil acid bass open in FL Studio
The plugin in FL Studio
  1. Download the latest release and unzip it.
  2. Copy the whole folder My lil acid bass.vst3 to C:\Program Files\Common Files\VST3\ (needs admin).
  3. FL Studio: Options > Manage plugins > Find installed plugins, then add My lil acid bass as an instrument. Other hosts: rescan.
  4. Play it from the piano roll, or turn its sequencer on and press play.

Not code-signed: if SmartScreen warns, click More info > Run anyway. The window needs WebView2 (built into Windows 11).

> download latest release

VCV Rack 2 module

40 HP. Windows, Mac (Intel and Apple silicon) and Linux. Step grid, voice, sequencer, CV and gate in and out.

The acid voice and the 32-step sequencer in one module. Clock it from your patch or its own tempo, play the voice from another sequencer with V/OCT, GATE and ACC, or send its line out to drive any other voice. Right-click to copy and paste patterns as step notation or JSON, or load the demo set.

  1. Download the .vcvplugin file for your system from the latest release.
  2. In Rack 2, choose Help > Open user folder and put the file in the plugins-<os>-<cpu> folder there.
  3. Restart Rack. My lil Acid Bass appears in the module browser under A_Development.

Not code-signed.

> download the vcv module > source and build steps

In your browser

One page, no install. Chrome, Edge or Firefox. Sound starts on your first click or key press.

My lil acid bassline

// loads the synth from GitHub Pages

> open it full screen