Pistol Instruments

About the OB-6 Editor

A free, browser-based patch editor and librarian for the Sequential OB-6 — the keyboard and the desktop module. No install, no account, no uploads: your browser talks straight to the synth over Web MIDI.

What is it?

The OB-6 is Dave Smith and Tom Oberheim's six-voice analog collaboration: two discrete VCOs per voice, the SEM-lineage two-pole state-variable filter that morphs continuously from low-pass through notch to high-pass, X-Mod, a 64-step polyphonic sequencer, dual digital effects and true voltage-controlled analog signal path. Its knob-per-function panel is glorious — but pulse widths, aftertouch routings, effect parameters, the sequencer's step data and every Globals setting still live behind button combinations. This editor puts every parameter on screen at once, organised the same way as the instrument itself.

Edits are transmitted instantly as NRPN messages, so the synth responds in real time while you drag a knob. Complete sounds travel as standard Sequential SysEx dumps, which means everything you save is compatible with any other SysEx tool.

What you can do

Edit everything

All program parameters — oscillators, filter, envelopes, LFO, X-Mod, aftertouch, effects, arpeggiator — plus the synth's Globals, with per-parameter NRPN/CC info for DAW automation.

Edit the sequencer

The 64-step, 6-voice polyphonic sequencer drawn as lanes you can draw notes into, with Play, Record and Transpose talking to the instrument's own transport.

See the filter

A live response graph follows the filter-mode knob as it morphs low-pass → notch → high-pass, and the band-pass switch.

Manage banks

Import and export .syx patches and banks, receive banks from the synth, favorites, search, and a staging area for compiling new banks.

Compare & morph

Snapshot two sounds as A and B, flip between them, or morph continuously from one to the other.

Work offline

Installable as an app (PWA); after the first visit it loads without a network connection.

Everything stays on your computer. Banks live in your browser's IndexedDB storage and can be backed up to a JSON file. The site has no analytics, no cookies and no server-side anything.

Getting started

Connect the OB-6 over USB (or a MIDI interface).
Open the editor in Chrome, Edge or Opera and allow MIDI access with SysEx.
On the synth: Globals → Param Xmit = NRPN, Param Rcv = NRPN, MIDI SysEx = USB.
Pick the OB-6 under MIDI Out and MIDI In, then press Get from Synth.
Choose Keyboard or Desktop Module in the Settings tab.

Full instructions live in the user manual.

Offline and air-gapped studios

The editor is a PWA: once loaded it keeps working without an internet connection. For a studio computer that is never online there is also a downloadable version: ob6-editor-offline.zip. Download it on any machine, copy it over, unzip, and double-click start-windows.bat (Windows) or start-mac.command (Mac). A tiny local web server starts (Python 3 is the only requirement) and the editor opens at http://localhost:8000, fully functional, with nothing ever sent anywhere. A README in the zip has the details.

About Pistol Instruments

Pistol Instruments is Patrik Pistol's collection of free, browser-based editors for classic synthesizers — including editors for the Sequential Prophet 12, Novation Peak/Summit, Moog Voyager and Roland JD-990. They share one philosophy: no installs, no accounts, no clouds — just your browser and your synth.

Thanks to

Dave Smith and Tom Oberheim, for the OB-6 itself, and the Sequential team for documenting the MIDI implementation in the operation manual.
The factory sound designers behind the 500 programs whose names ship with the librarian.
The Web MIDI API authors and implementers.

“OB-6”, “Oberheim” and “Sequential” are trademarks of their respective owners, used here only to describe compatibility. This site is not affiliated with Sequential LLC or Oberheim Electronics.