op1-overdub — original OP-1, firmware 246

New synth engines, FX with animated screens, and keyboard modes for the original OP-1.

They are patched into TE's own firmware: every stock engine, FX and feature keeps working. Like an overdub on tape, it adds new layers over TE's firmware without erasing anything underneath.

Not affiliated with or supported by teenage engineering. You flash this at your own risk (see safety).

screens

Every knob drives part of the picture, in its own colour.

FX screens in motion

ensemble: animated choir — ensemble — a choir

pingpong: animated table tennis — pingpong — table tennis

distortion: pedal modes — distortion — modes

what's in it

	blue	green	white	orange
synth engines — in the engine list with their own presets and screens
vatwo-oscillator virtual analog with sub and noise	wave (sine → saw → square → pulse)	osc 2 detune	noise	sub
wavetable8 banks of morphing wavetables	position	bank	warp	unison
graingranular; plays a built-in bank, or the sample in any sampler slot	position	grain size	density	spray
FX — on synth, drum and master; stereo as master FX
ensembleBBD chorus, CE-2 style by default	rate	depth	character (CE → dual → string ensemble)	mix
pingpongping-pong delay	time	feedback	tone	mix
distortionTUBE, MUFF, FUZZ, CLIP, FOLD, CRUSH	drive	voice (low-pass ↓, wah ↑)	character	mix

keyboard

HOLD — SHIFT + T2 on the synth screen latches released notes; again to release.
CHORD — hold SHIFT and play a chord (up to 4 notes); then every key plays that shape. SHIFT + one key turns it off.

install

Download stock firmware 246 from TE: op1_246.op1.
Download overdub-*.zip from releases and unzip it.
python3 apply.py op1_246.op1 (Python 3.10+, no other dependencies) asks which features to install (every engine, FX, HOLD and CHORD; all on by default) and writes OVERDUB.OP1. It checks that your file is stock 246 and that the result is exactly the expected image for your choice.
On the OP-1: hold COM while switching on, press 1 (upload firmware), connect USB, copy OVERDUB.OP1 to the OP-1 disk, eject. Same procedure as an official update.

Without the questions: --all, --without amp,crush, --only va,grain,hold; --list shows the features. A left-out engine or FX is only hidden from the lists, so sounds saved with it still load.

The release contains only our code, our database rows (engine/FX names and presets) and our SVG screens. TE's firmware never leaves your computer.

safety

The bootloader is never touched. te-boot.ldr stays byte-identical to stock (the tools refuse otherwise), so you can always go back: hold COM at power-on, upload stock op1_246.op1.
Before going back to stock, delete sounds saved with these engines or FX. Stock firmware doesn't know their names and stops at boot on such a sound. If that happens: COM at power-on, then factory reset.
Never name a firmware file with FRC, RBT or KEY in it: the OP-1's updater treats those as commands. apply.py and build.py refuse such names.

links

sourcegithub.com/wsbuck/op1-overdub downloadreleases how it worksnotes/