This is an independent HTML/Web Audio homage to the original OP-1, not official Teenage Engineering firmware or an exact emulation. Version 0.3 introduces mono PCM clips, microphone capture, sample playback, waveforms, and WAV/JSON project export. Notes from v0.1/v0.2 remain compatible.
- Play notes: bottom octave Z S X D C V G B H N J M; upper octave Q 2 W 3 E R 5 T 6 Y 7 U. Use the on-screen keys too.
- Control a sound: select SYNTH, choose sound 1–8, then press screen keys 1–4 to change engine, ADSR, effects or LFO. Drag / scroll the coloured knobs; double-click to reset.
- Drums: switch to DRUM, select a kit 1–8, then tap different notes for synthesized percussion.
- Record: choose TAPE, select a track with screen keys 1–4, arm REC, then PLAY. Perform while tape rolls. STOP completes the recording. REC can be armed while the tape is moving to overdub. Clicking REC again disarms it.
- Tape: left/right transport arrows move four seconds; SHIFT + rewind returns to zero. Use SET IN / SET OUT to mark a loop region, ZOOM to inspect it, and click the screen ruler to seek. LOOP repeats the chosen region.
- Clear a track: hold SHIFT (or click the SHIFT button), then press ⌫ while in TAPE mode. Clearing a track can now be undone during the current session.
- Timing: CLICK enables a beat metronome, GRID quantises new note onsets to the nearest sixteenth note, and the tape screen shows musical bar guides.
- Edit tape: select a note or audio waveform on the TAPE screen. SPLIT divides it at the playhead, LIFT removes it to a clipboard and DROP places a copy at the playhead on the chosen track. UNDO and REDO protect edits during this session.
- Mixer: four knobs change track volumes. Hold SHIFT while changing a knob to pan its corresponding track.
- Sequencer: ✣ opens a simple 16-step sequencer. Select a note by playing it, then click steps to place that note. RUN auditions it. To capture it, record to tape while it runs.
- Audio sampling: MIC REC requests microphone permission and records into the selected track while tape runs. RESAMPLE captures the instrument's actual audio mix including any other tracks (and the metronome if enabled). + TAPE AUDIO imports a recording at the playhead. + SAMPLE loads an instrument sample; SAMPLE KEYS plays 4, 8 or 16 sliced pads using the instrument keyboard. Browser storage is used for local audio cache.
- Save: local autosave stores clip metadata and sample audio separately in IndexedDB. SAVE PROJECT embeds audio in portable JSON, and EXPORT WAV renders the combined note and audio tracks.
Known limits of v0.2: this is still an independent OP-1-inspired instrument, not a complete emulation. PCM clips are 22.05 kHz mono; waveform operations and sample pads are simplified, and full hardware tape tricks/MIDI are not yet implemented. Playback and WAV export synthesize from the saved notes.
Unofficial fan-made recreation. OP-1 and Teenage Engineering are trademarks of their respective owner. No original firmware, artwork or samples are included.