UNOFFICIAL FIRMWARENOT FROM TEENAGE ENGINEERING · COMMUNITY BUILDS
Community developers are writing their own custom firmware, also called alternative firmware, for the OP-1. This is a selection, not every fork or experiment: we list the projects with a working build and a real following, and check them every day. FW Radar doesn’t host these files and doesn’t send alerts for their versions: each link opens the developer’s page.
5 PROJECTS · LAST CHECKED 25 OCT 2026
Get an email when new custom firmware for the OP-1 is found
01BETA
op1r
by pcppcp
Patches TE's OS 246 in the browser into a custom firmware: new synth engines (supersaw, FM bell, granular), tape echo, Clouds and Elements-style effects that also work as master FX, a quad LFO, a Euclidean sequencer, a sample editor, better tape tools and plugins you add or remove over USB MIDI.
Unofficial, not supported by Teenage Engineering; can void the warranty. Original OP-1 on OS 246 only, not the OP-1 field. Back up the OP-1 first. The original 246 can always be flashed back.
The tool behind most OP-1 mods: unpacks and repacks the firmware and applies ready-made mods such as the hidden iter synth, the hidden filter effect, community iter presets, subtler effect defaults and new graphics. A desktop GUI exists (op1REpackerGUI).
Voids the warranty and can brick the OP-1 (the developer says so). The ready-made mods were tested on OS 235. Back up first.
A browser workshop that builds your own OP-1 firmware from TE's OS 246 file: pick the synths, effects and tools you want (op1r's included, plus its own such as the Gin drum synth), with 152 synth presets; later updates go over USB MIDI.
Unofficial, not supported by Teenage Engineering; can void the warranty. Original OP-1 on OS 246 only, not the OP-1 field. Back up the OP-1 first. A factory reset clears user data.
Adds scale quantisation to the synths: hold shift and press 2, then pick the scale with the white or orange encoder. A Python script patches TE's OS 246 file.
Unofficial, not supported by Teenage Engineering; can void the warranty. Original OP-1 on OS 246 only, not the OP-1 field. Back up the OP-1 first.
READ THIS FIRSTAt your own risk, and it may void your warranty. Read the developer’s install notes, back up your presets, and make sure you know how to go back: official 246 and how to install it →
Running one of these?Mark it in your rig: the OP-1 won’t show as out of date, and you still hear about official updates.
An alert the day a new OP-1 firmware ships, by email, Telegram or push
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A public rig page to share, if you want one
The Teenage Engineering OP-1 is no longer made, but Teenage Engineering can still ship firmware for it and we keep checking the official download page. One message per release. No spam, no newsletter.
It’s written by independent developers, not by Teenage Engineering. Some projects are stable, others are early betas: read each developer’s notes before you flash.
We pick the ones worth trying: a build you can install and a real following, from GitHub stars and downloads or from the community. Forks that only rename a project or add a few presets stay out, and brand-new projects get a second look after their first week.
Does FW Radar track custom firmware versions?
We note the latest version each developer has published when we check the list, every day, but we don’t send alerts for it: alerts are only for official Teenage Engineering firmware.
