Oberheim TEO-5 42-Key 5-Voice Synthesizer

Download the firmware ZIP from the Oberheim support page. Connect the TEO-5 to your computer via USB-B or MIDI interface. Open the .syx file from the ZIP in MIDI-OX (Windows) or SysEx Librarian (Mac) and send it to the instrument. No other audio or MIDI software should be running during the update. After completion, press Global and run Reset Globals then Cal Voices to recalibrate.