SubForge

SubForge is a monophonic bass synthesizer with a built-in 16-step sequencer. It comes as a CLAP and a VST3 plug-in. Free and open source.

Features

• Saw, square (with adjustable width), pulse, sine and triangle waveforms, band-limited to keep aliasing low, plus a sine or square sub-oscillator. The square also has LFO pulse-width modulation (PWM) and a Sag control for the classic acid square.
• Filter with LP 24, LP 12, BP 12 and diode ladder modes, key tracking and an accent sweep.
• Pitch envelope, tempo-synced LFO, glide, click, distortion (overdrive, distortion, fuzz, tube amp) and 4x oversampling.
• 16-step sequencer with pitch, accent and slide per step, synced to the host's tempo, and eight pattern slots you switch with automation or MIDI notes.
• 115 sound presets and 62 patterns, plus your own presets and patterns.
• Vector interface that scales from 75 % to 200 %.

Playing with the sequencer

While the sequencer runs, the notes you play don't sound themselves. They transpose the pattern: the key you hold becomes the pattern's root note. Release all keys and the Root setting applies again. Pitch bend, mod wheel and aftertouch still work as usual. With the sequencer off, notes play SubForge like any synth.

Exporting patterns as MIDI

Right-click a pattern slot and choose Export MIDI to save it as a MIDI clip, then drag the file into your DAW. A clip is one pass of the pattern, with its accents, slides, gate and swing.

Free bass synth for Linux and Windows

SubForge is a free, open source bass synth plug-in in CLAP and VST3 format. It runs on Linux and Windows, and there is an experimental macOS test build. Use it for acid lines, sub bass and sequenced basslines in any host that loads CLAP or VST3 plug-ins.

Note

SubForge is developed in spare time and shared as it is. There is no support and no fixed schedule for updates.