The Ott-Organ is a beautiful tiny rehearsal instrument, which was published in 2004 by Christian Datzko. This tracker organ was built by Dieter Ott (Göttingen in Northern Germany) in 2003. It has originally 5 Stops on a single manual (56 keys). The manual is always coupled to the pedal (30 keys). Stops are Gedackt 8′, Rohrflöte 4′, Prinzipal 2′, Quinte 1 1/3′, and Oktave 1′.

The extension adds the following features:

  • A 16′ pedal stop (Gedackt 16′)
  • Stop action, key action, and blower noises (adjustable)
  • Addition of dual portrait and landscape jambs (with French stop names, graphics artist: Stéphane Royer)

This extensions works with Hauptwerk 4 and Hauptwerk V.