Proportional Key Action
The new organ for Sacred Heart Co-Cathedral is placed in the rear gallery on either side of the 40-foot high resurrection window. This placement posed challenges in designing the key action, leading to the use of new technology for part of the action and coupling action.
The three traditional manual divisions, Great, Positive and Swell, are housed with the console on the left side of the window and have normal suspended mechanical key action and mechanical couplers. The Grand Choir and Pedal divisions are modeled after the Resonance division in the famous 1775 Jean-Esprit Isnard organ at St. Maximin, Provence, and share their stops, using independent stop actions to each division. Running a traditional mechanical key action from the console in the left case past the 22’ width of the large window would have been impractical. Our solution is to use the electric proportional key action developed by NovelOrg of Longueuil (Montreal), Québec www.novelorg.com.
The NovelOrg proportional key action is an all-electric action with sophisticated electronic control in which the magnets that open the pallets in the wind chests follow exactly the motion of the key. This allows the control of speech and release characteristics of a mechanical key action. Applying this action to the Grand Choir and Pedal divisions makes their placement in the case opposite the console possible while retaining the sensitive control of our normal key actions.
The couplers of the Great, Positive and Swell to the Grand Choir work through the NovelOrg proportional action. The mechanical manual couplers to the Great and Positive manuals may be operated optionally through the proportional system.
Pasi Organ Builders is using this innovative approach to the key action in order to provide the comprehensive tonal scheme required by the monumental proportions of the new cathedral and the challenge posed by the large window between the two organ cases.