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| Concerning the sound and case of an organ |
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| Each row of pipes (stop) has its own
special tonal characteristic, and encompasses large, deep-sounding pipes and
small, high-sounding ones. The pipes are made either of wood or of metal. For
their physical production of a tone, pipes may either have lips or a tongue
(flue- and reed-pipes). A small organ contains 10 to 15 stops, an organ of middle size has some 15 to 40, and a large organ from 40 to over 100 stops, and accordingly from several hundred to several thousand pipes. The size of the pipes (Scaling) ranges from 5 mm to over 10 m in length and 3 mm to 60 cm in diameter. |
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 The
connection between the keys of the manuals or pedals and the pallet valves
below the pipes is known as the key action. The connection between the
drawstops at the console and the stop control at the windchest is known as the
stop action. In earlier times, the transfer of movement occurred mechanically, using levers and rollers, etc.. From about 1900, this transmission was made pneumatically and as the 20th century moved on, the communication was made electrically. Today, the key action is extensively operated according to mechanical principles, as this provides the most sensitive and direct system for the player. Stop action is operated either mechanically or electrically. The transmission via compressed air (a pneumatic system) began to be used in organ building in about 1900. The organ builder must understand all these systems, for the maintenance and restoration of older instruments.  The blower produces a regular
pressure of airflow, which flows through the windchest and thus produces a note
from the pipes. In former times, the airflow was produced by special bellows,
developed from a simple blacksmith's bellows, but which received greater
perfection as the centuries went by. Today, we always use an electrical blower,
which supplies a pressurised reservoir.  The wooden case of an organ is both the
framework and covering for the different parts of the organ.  The facade of the organ is also its show-case. The
facade often presents itself as splendid and magnificent, and is usually
dominated by Principal pipes. In older organs especially, it is most richly
decorated and painted. |
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- The Windchests
- Concerning the sound and case of an organ
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| ©
2000, Association of Swiss Organbuilders (GSO) CH - 8001 Zürich. All rights reserved |