About the JD-990 & JD-800 Editor
A free, browser-based editor and librarian for the Roland JD-990 and Roland JD-800 — built by Patrik Pistol at Pistol Instruments, for the love of these classic synthesizers.
Why it exists
This project started for a simple, personal reason: Patrik Pistol wanted an easy way to switch patches and edit his own Roland JD-990. The JD-990 is a fantastic-sounding rack synth, but its small display and deep menus make hands-on sound design slow. Existing editors were old, paid, or tied to operating systems and plug-in hosts that no longer run well.
So instead of fighting the front panel, he built a modern editor that runs entirely in a web browser over the Web MIDI API — no installation, no plug-in host, nothing to buy. Open a tab, connect your synth, and every parameter is in front of you. What began as a personal tool grew into something polished enough to share with the whole JD community.
What makes it special
- Everything in the browser. Edit every Patch, Tone, Performance, Rhythm and System parameter live over SysEx — you hear changes instantly. Fetch patches and banks, switch sounds fast, and save or load
.syxfiles. - Two synths in one. Full support for the JD-990, plus JD-800 Single Patch editing — the editor handles each synth's different model ID and SysEx addressing automatically.
- Graphical envelopes and a clean, fast UI with light/dark themes, installable as an offline app (PWA).
- Your data stays yours. Nothing is uploaded. Settings and your private patch banks live only in your own browser.
A unique highlight: the SR-JV80-04 Vintage Synth card — both banks built in
The JD-990 is famous as a vintage-synth machine, and the SR-JV80-04 “Vintage Synth” expansion board is its perfect partner. What's special here is that the editor includes both of that card's patch banks, ready to select and play:
- Exp: SR-JV80-04 JD — the 256 patches programmed specifically for the JD-990 (“EXP B”).
- Exp: SR-JV80-04 JV — the 255 standard card patches.
And because the JD-990 can't select card patches over MIDI the usual way, the editor sends each patch's full data to the synth so it loads and plays instantly — the card's waveforms also appear directly in the tone editor under WG Source = Exp. As far as we know, no other tool brings the SR-JV80-04 to the JD-990 this completely.
Help wanted: building the complete Roland expansion library
The goal is to include all of Roland's official SR-JV80 expansion cards in the editor — every card's waveforms and, ideally, its patches as selectable banks. The waveforms can be added from the manuals, but the patch banks need real .syx dumps, and the JD-990 can only be dumped one patch at a time from its own front panel.
That's where the community comes in. If you own a JD-990 and an SR-JV80 expansion card, you can help — the editor has a built-in “Capture card → bank” feature that makes it easy:
- Connect your JD-990 (MIDI In + Out) and open My Banks → Auto-capture.
- On the synth, load the card's patches (
PATCH → UTILITY → CARD → Ld PRM → EXP BOARD) and step through them with the VALUE dial — the editor grabs each one automatically. - Click Download .syx and send the file (tell us which card it's for).
With your dumps we can add each card as a proper, playable bank for everyone. See the manual for the full step-by-step. Thank you — every card brings the library closer to complete.
Other things you might find interesting
- Every parameter, name and range was decoded from the official Roland manuals and verified byte-for-byte against the documented SysEx examples (checksums and all).
- Bulk transfers are deliberately paced so older Roland hardware doesn't drop packets — a common cause of “it doesn't sound the same after loading”.
- You can keep your own purchased or third-party banks as private, local banks (My Banks), reorder and edit them, write a whole bank to the synth, or export a backup — all without anything leaving your computer.
- It's designed to be extensible: new expansion cards are added as small data files, so the library can keep growing.
About Patrik Pistol & Pistol Instruments
Patrik Pistol is a musician and developer behind Pistol Instruments, which also makes the Novation Peak editor that inspired this tool's look and feel. This editor is offered free to the JD-990 / JD-800 community.