TR4 is a four-track tape recorder and editor, built like an instrument. A giant disc with real physics sits at the center. Drag it to scrub with varispeed — even in reverse. Flick it and it spins down like real hardware. One rotation is two seconds of tape. MADE FOR HARDWARE Plug in any class-compliant USB audio device — such as the EP-133 K.O. II — and TR4 recognizes it by name, captures true stereo at 48 kHz, and arms itself. Press play on your groovebox and recording starts on the exact downbeat — from the MIDI signal if your device sends one, from the first sound if it doesn't. Stop the groove: the take ends, rewinds to zero and re-arms for the next pass. Record four passes onto four tracks without ever touching your iPhone. MIDI • Follows MIDI transport — start, stop and continue, from any device that sends it • MIDI Learn — map play, stop and record to a pad, a key or a footswitch • Live monitor — see exactly what your gear is sending RECORD • Four tracks with overdub — record one while the others play • 20 minutes per tape • Built-in mic, headset, Bluetooth or USB stereo input • Auto-record on USB signal, with noise calibration • Metronome with 3-2-1 count-in and a visual beat that never leaks into the mic • Auto-save: every take is kept as raw audio plus edits EDIT • Per-track volume, pan, mute and solo • Non-destructive crop with draggable handles • Loop playback while you fine-tune MAKE IT YOURS • Hold the disc to swap its look — a full collection of designs, from vinyl to street art EXPORT • Mix or separate stems, straight to the share sheet • M4A included free; WAV & AIFF with TR4 Pro TR4 PRO — ONE-TIME PURCHASE Unlock everything, once: WAV & AIFF export, separate stems, unlimited projects, all disc skins and voice transcription. No subscription. No accounts. No ads. No tracking. Your recordings never leave your device unless you export them.