BassMatrix
Key Features
- TB-303 acid bass engine powered by the Open303 DSP project with faithful diode ladder filter modeling
- Built-in step sequencer with up to 24 programmable patterns, each with gate, slide, accent, and octave shift per step
- Four sync modes: Host Sync (DAW-locked), MIDI Play (chromatic), Key Sync (arpeggio-style), and Internal Sync (standalone jam)
- Sawtooth and square waveforms with dedicated knobs for cutoff, resonance, envelope modulation, decay, accent, and tuning
- Pattern randomization for quick inspiration and a clear function for starting fresh
- Cross-platform support with VST3 on Windows and Audio Units on macOS, plus a standalone executable
Description
BassMatrix by Witech is a TB-303 emulation built on the Open303 DSP engine, delivering the squelchy resonance and acidic bite that defined acid house, techno, and electro. The synth engine faithfully models the 303's diode ladder filter, with hands-on controls for cutoff, resonance, envelope modulation, decay, and accent.
The built-in step sequencer lets you program up to 24 patterns with per-step gate, slide, accent, and octave shift controls. Patterns can loop automatically or switch via MIDI notes in Host Sync mode, making it straightforward to arrange full acid sequences inside your DAW.
BassMatrix v2.0 added macOS support via Audio Units alongside the existing Windows VST3 build, plus a standalone mode for jamming without a DAW. The interface keeps things visual with large knobs for tuning, cutoff, resonance, env mode, decay, and accent, and a waveform toggle between sawtooth and square.
As an open-source project hosted on GitHub, BassMatrix invites community contributions and ongoing development. Users report that the sound holds up well against other 303 emulations, with particular praise for the authentic filter sweep and resonance character.
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Frequently Asked Questions
Is BassMatrix a faithful emulation of the Roland TB-303?
BassMatrix uses DSP code from the Open303 open-source project, which models the 303's analog signal path including its distinctive diode ladder filter. While no software can perfectly replicate analog circuitry, users report that BassMatrix captures the signature squelchy resonance and acid character convincingly.
Can I use BassMatrix to sequence patterns inside my DAW?
Yes. In Host Sync mode, BassMatrix locks its internal sequencer to your DAW's tempo and transport. You can switch between the 24 stored patterns by sending MIDI notes, which makes it easy to arrange full acid sequences across a track.
What happened in the v2.0 update?
Version 2.0 added macOS support via an Audio Units (AU) component, joining the existing Windows VST3 and standalone builds. This brought BassMatrix to Logic Pro, GarageBand, and other AU-compatible hosts for the first time.
Is BassMatrix open source?
Yes. The full source code is available on GitHub under the olawistedt/BassMatrix repository. It is built with the IPlug2 framework in C++, so developers can submit bug fixes, add features, or study the DSP implementation.
