Stops; Flue Pipes; Reeds - Johannus Opus 5 User Manual

Stops

The stops are on so-called tab stops. These are switches that will come back in their middle
position after being switched on or off. Therefore, in every tab a light will light up when that stop
is switched on. These stop lights also work with the use of presets and free combinations.
The last stop of each group is a MIDI-stop. For the use of these stops see chapter "MIDI
applications".
On a pipe organ you switch a rank of pipes on or off with the stops. By varying the combinations
of stops the organist can create dynamic and colorful changes. This means that some
knowledge of the traditional pipe organ is necessary to make good stop combinations. You
should know a little bit about the different sounds of the different organ stops. That is why we
give a brief explanation about these different kinds of organ stops.
In the appendices you will find extensive examples of registrations.
Organ pipes can be divided in two main groups:
! Flues

! Reeds

Flue pipes

Flue pipes occur in two versions: open or (half) stopped. An example of a half-stopped pipe is
the Rohrflute. On the canister-stopper a small open tube has been soldered. An example of an
open flue pipe is the Principal. Normally the pipes of this stop are located in the facade of a pipe
organ. Flues can be subdivided in the following categories:
Principals
Principals are the Principal, Octave, Twelfth, Superoctave, Mixture, Scharff, Cymbal,
Rauschpfeife and Sesquialter. The last 5 stops sound with more than one pipe of different pitch
together per note. So called multi rank stops.
Strings
These are the narrow scaled, open flue pipes like: Viola di gamba, Vox Celeste and Salicional.
Flutes
Flute stops, open as well as stopped, are made of metal or wood. For example: Stopped Flute,
Gedackt, Bourdon, Subbass, Nazard, Waldflute, Gemshorn and Rohrflute.
Reeds
In a reed pipe the wind is blown into the pipe bringing a reed into resonance. This resonance
is 'amplified' and 'colored' by a tube (resonator). Reeds with a conical resonator are: Bombarde,
Trumpet, Schalmei, etc. The group of cylindrical resonators are: Fagotto, Cromorne,
Krummhorn, etc. The following reeds have a short resonator: Regal, Vox Humana, Ranket, etc.
User's Manual
JOHANNUS JOHANNUS
9
Opus 5, 10, 20 and 30 AGO