SUBHARM
A polyrhythmic synthesizer: 2 VCOs with 4 subharmonics, 2 four-step sequencers and 4 polyrhythmic clock dividers.
A rack of synthesizers in your browser
All the gear, none of the GAS.
Synthesizers, drum machines, sequencers and effects that you patch together with cables. Play them from the computer keyboard or a MIDI controller, and write songs in the built-in sequencer. Nothing to install.
Free · runs in a modern desktop browser · best with headphones or speakers
What's inside
Every device runs sample by sample in one audio engine, so a cable can take audio, control voltages, gates or clocks from any output to any input, as on a modular synth.
Patch anything
Drag cables from any output to any input on the front, and route the audio on the back of the rack (Tab turns it around).
26 devices
Synths with up to 8 voices, drum machines, a pad sampler, a drone machine, a note grid, MIDI effects, LFOs, a mixer, a compressor and seven effects. Add as many as you like.
Synth Editor
Design your own synth: lay out its front and back panels, then wire oscillators, filters, envelopes and sequencers behind the knobs. It plays while you build it.
Song sequencer
Tracks on MIDI channels, a piano roll with selection and editing, recording, loops, MIDI file import, and export of the song as a WAV file.
Automation
Turn any knob while recording and it is written into a CV track, played back with the song and editable as a curve.
MIDI and keyboard
Play from a MIDI controller or the computer keyboard, map controllers to knobs with MIDI learn, and sync to MIDI clock.
Sessions and patches
Dozens of factory patches, your own patches and sessions saved in the browser, and export or import as files.
Over 5000 tunings
Retune the synths to historical, just and microtonal scales from a large archive of tunings.
Detachable sequencer
Move the sequencer into a window of its own, on a second screen, and it comes back when you close it.
Keyboard control
Every button can be pressed from the computer keyboard; hold Shift to see which key does what.
Screenshots
Click a picture to see it full size.
The devices
Original instruments inspired by classic designs, each with its own panel, sound engine and patch sockets.
Synthesizers and drum machines
DRAM
An 8-step analog percussion voice, 2 VCOs, noise, a ladder filter and decays per step. Kicks, toms, clanks.
BROTHER-32
A mono semi-modular synth with a 32-step sequencer, ladder filter, envelope and a compact keyboard.
MAZE
Two parallel bit-shift sequencers, two VCOs, a wavefolder and a state-variable filter. Generative patterns.
MYSTIC
8 voices, wave-scanning oscillators with mutants, two filters, five envelopes and LFOs, a 16 slot mod matrix, 8 macros, four effects in stereo, an arpeggiator. Edit pages around an OLED.
LLM DRAM
An early 80s style drum machine: 24 gritty 8/12-bit sounds on 16 pads, a mixer, tuning, wave designer, filter and a 64-step sequencer.
LUNAR 21
An ambient drone machine: six drone voices, two VCOs on touch plates, aggressive resonant filters and a dual effector with cartridges.
PARA D
A classic analog monosynth design with four oscillators, played mono, in unison or as four voices through the ladder filter, with a stereo chorus, a distortion, an arpeggiator and a 32-step sequencer.
MESIAH-6
6 voices of 2 morphing oscillators, sub and noise, slop, high-pass and low-pass filters, poly mod, an LFO, distortion, two effects, unison with chord memory, an arpeggiator and a 64 step sequencer.
CSS 90
8 voices of two complete channels (oscillator, high-pass and low-pass filters with their envelope, sine, amplifier), velocity and per note aftertouch, a sub oscillator, a ring modulator, chorus or tremolo, 22 preset voices and the ribbon.
MOUNT
8 voices of 3 oscillators (with wavetables), a multimode filter, three envelopes, two LFOs, a mod matrix with ANIMATE buttons, an arpeggiator, and distortion, chorus, delay and reverb.
CRATE 60
A pad sampler and sequencer laid out as a compact modern beat machine: 64 lit pads, a factory kit, drop your own samples on the pads or record them, chop them, and play them into 16 sequences with swing, note repeat and 16 levels.
MINIMAD
A digital paraphonic synth with 14 oscillator types (wavetable, FM, Karplus, modal, chords, formant...), an analog style filter, a cycling envelope, a 5 x 7 mod matrix, an arpeggiator and a 64-step sequencer, played from a flat keyboard that reads pressure.
CUSTOM SYNTH
A synth you design in the Synth Editor: full or half width, 1 to 5 units high, one voice. Save a design in the browser and add it again from ADD DEVICE.
Sequencing and modulation
GRID 32
Draw notes on a 32 x 32 LED matrix: columns are steps, rows the notes of a scale. Two KEY / GATE pairs (lowest and highest note), ties, chance, swing, directions, 8 patterns, and MIDI to play the rack's synths.
Half width
MIDI FX
Effects on the notes between the keys and the synths: notes moved to a grid, transposed, harmonized into chords, kept in a scale, arpeggiated and repeated as echoes that can rise or fall.
DUAL LFO
Two LFOs (sine, triangle, saw, ramp, square, S&H) with rate and level, and sync inputs. Half width.
Half width
Mixing and dynamics
MIXER
Six mono channels with level, pan, mute / solo and an aux send / return, into the main stereo out.
COMPRESSOR
A stereo compressor with sidechain input, gain reduction meter and an oscilloscope of the output. Half width.
Half width
Effects
REVERB
Convolution reverb with 12 rooms, from drum rooms to churches, with pre-delay and tone. Half width.
Half width
DELAY
Stereo / ping-pong delay, free or synced to the tempo, with feedback tone. Half width.
Half width
PRISM
A five band equalizer: shelves, bells, low and high cuts, and a display with the spectrum and the curve. Drag its points to shape the sound.
Half width
HYPER
Lo-fi distortion and bit crusher: tape wobble, 4 saturations, sample rate and bit reduction. Half width.
Half width
TAPE
A tape machine for hazy, wobbly, nostalgic sound: wow and flutter, saturation, a darkening tone, hiss and dropouts, three machines and a tape stop. Half width.
Half width
UNIVERSE
11 granular, looping, glitch and delay effects x 4 variations, a reverb and a phrase looper. Half width.
Half width
COSMOS
Hall, Room, Plate, Spring, DualVerb, Reverse, ModEchoVerb, Void, WarpVerb, TremoloVerb, DynaVerb, Shimmer; 10 knobs per algorithm, presets, freeze. Half width.
Half width
Utilities
REROUTE
A thin row of 8 channel pairs: a front socket goes out on the back, a back socket comes out on the front. Cable one REROUTE's back to another's back to carry a signal across the rack without a long cable.
The code
GASFREE is plain JavaScript with no build step and no dependencies, under the MIT license. Download it from GitHub and open app/index.html to run it from your own computer, even offline. Bug reports, ideas and pull requests are welcome there.
Open the rack
Click Audio on and press Space to play the patch. Help in the toolbar explains the rest.
Launch the app