Wind chest
The wind load is an essential component of an organ or an organ-like instrument which the wind generator (blower or bellows) coming wind distributed to the individual, standing on the wooden body of the wind chest, pipes. It contains the valve technology operated by playing and stopping action to play the notes and to switch the stops on and off . The organ pipes are usually placed directly on the so-called pipe rod on the top of the wind chest and arranged in a regular grid: pipes of a tone color are arranged next to each other according to pitch, pipes of the same tone one behind the other. In the case of organs with pneumatic or electric action, the pipe arrangement can also be designed in a partially arbitrary manner.
With wind chests, different designs - with sub-variants - have developed since the Middle Ages, which can be differentiated according to the type and system of valve technology.
Small organs get by with a single wind chest, larger organs have at least one drawer per manual and pedal unit. The grouping of the pipes for the design of the prospectus can make it necessary to divide them into individual shops. Until the end of the Middle Ages, instruments were provided with a simple form of the wind chest, namely with one or more block movements . Instruments of this type are called block organs.
Designs
There are three basic types:
- Tonkanzellenlade - All pipes of one pitch are on a common tone canopy.
- Register chamber drawer - All pipes of a register are on a common register chamber.
- Box drawer - All pipes are placed directly on the wind box.
Sound canister drawer
With the Tonkanzelle drawer, all the pipes that can sound when a key is pressed share a chamber, the so-called Tonkanzelle and thus also a game valve.
Slider drawer
General
The slider drawer gets its name from the type of register control. Long wooden strips, called loops, have a hole for each pipe. Below the loops is the foundation board of the wind chest, also with holes equally spaced and the same size. The pipe sticks are located above each loop . In principle, these are almost similar to the loops, and the same holes are also in them. Like the foundation board, however, they are immobile. They are also thicker and often divided into several pieces in length. The grid boards with round wood or threaded rods are attached to the sticks at a distance of usually about 15-20 cm ; these have the sole task of supporting the pipes placed inside. Due to the thickness of the sticks, it is possible to tempt the bores for wind guidance to the side if necessary, if larger pipes do not have enough space in the location that is actually exactly assigned to them.
The sticks lie on small strips of wood or even just individual pieces of wood (dams) . Paper or cardboard is usually glued to this in order to tare the height distance precisely so that the loops can be moved easily on the one hand, but are also airtight on the other. The loop is mechanically connected to the register pull (or, in the case of electrical register actions, to the loop pull motor or magnet). If it is moved (i.e. the register is switched on or off), its holes are either in alignment with the holes in the foundation board and sticks and the register can be heard, or the loop otherwise seals the holes in the foundation board of a deactivated register in a windproof manner. Bows are mostly made of wood, but there are occasionally plastic ones. With old organs in particular, "wood on wood" occasionally runs, the loops are not sealed either above or below. As a rule, however, a wide variety of materials (foam, latex, fiberglass rings, lounger, telescopic sleeves) are used to seal the loops upwards and downwards.
Below the foundation board-degree angle 90 extend in the Kanz Ellen . Each is supplied with wind when the associated valve is open, i.e. the associated button is pressed. Underneath the pulpit, or more precisely the pulpit boards or partitions, there does not always have to be an additional, solid board. Likewise, in the valve area, the spaces for receiving the valve guide pins can only be closed with glued-in pieces of wood and the area can then be planed. Even the front area in front of the valves, which is no longer enclosed by the wind box, does not necessarily have to be closed with a wooden board; other materials such as leather or paper may also have been used, especially for historical organs. Especially when using a wooden board, the windproofness of the chambers can only be guaranteed if the chambers are generously filled with glue when making the wind chest.
The valves are enclosed in a wind box, into which the wind from the fan or the bellows located downstream is fed directly. Other parts that are in or on the wind box are the trigger wires of the action, the pulpets for sealing the exit points of the trigger wires and the valve springs. At the accessible front of the wind chest, the wind box is closed with sheet piles . These can be removed so that repairs can be made to the valves if necessary.
In historical organs there is often only a thick layer of leather as a seal on the valves. A peculiarity of these rather economical sealing layers, measured by modern standards, is that the pressure point can be felt very clearly even on smaller organs with relatively small valves. However, the valve rattle can be heard clearly from case to case. Today the face side of the valves is often also covered with leather and the leather layer of the valves itself is supplemented by a lower layer of felt. The opening and closing of the valves is almost inaudible.
As a rule, the wind box including the valves does not have the same depth as the wind chest itself. The area in front of it was particularly popular in the 1950s to 1970s to build shop bellows . Due to the extremely close location of this bellows to the pipes, it was precisely this type of regulating or compensating bellows that was able to ensure a particularly stable wind supply. Today we mostly refrain from building shop bellows. The advantage of the very stable wind supply means (measured by today's standards and listening expectations) that the organ sound is sterile and not very lively. Only when there is an extreme lack of space (for example with chest organs ) this form is still suitable today.
Until the development of other types of drawers in the 19th century, the sliding drawer was almost the only design. Only the spring drawer was an occasionally used alternative. The slider drawer is again the most widely used system these days.
The oldest extant slider chest in the Ostönnen organ can be dated to before 1440. The first precise descriptions of slider chest organs come from this time.
For modern music, only the sliding drawer in connection with a mechanical or an appropriately equipped electrical stop action offers a further advantage. Individual stops can only be pulled "halfway", which means that the pipes do not receive the amount of air intended for them, which leads to special sonic effects.
Special designs
To register, sometimes space or weight, save the New organ, but nevertheless allow a timbre packed game, there are various ways of reducing construction windchest loop or key action and play valve.
Twin drawer (interchangeable loop)
The twin drawer (also called a sliding drawer ) is a special form of sliding drawer in which individual or all registers can be registered mechanically on different manuals without coupling . Technically, this is done by alternating loops.
Twin drawers with interchangeable loops are mainly found on small organs , especially if the space available is not sufficient for two “independent” manuals. The instrument then has a complete collection of pipes, so to speak, but not two independent manual works (for example: main and chest works). All pipes (or at least all pipes of all manual registers) stand on a single wind chest. Each of the registers set up in this way can optionally be played on one of the two manuals (but not on both at the same time). The alternating loops make it possible to extract two audible works from the entire pipe inventory.
Sometimes there are also twin stores in organs with two independent manuals. Sometimes only individual stops from one of the manual works are equipped with alternating loops, for example in the choir organ in St. Aposteln (Cologne) . In the case of other instruments with two independent manuals, (at least) one is equipped with interchangeable loops. The registers equipped in this way can then be made playable on an additional third manual (without its own work), cf. z. B. the organ of St. Clemens (Hiltrup) .
The wind chest contains two chambers (and valves) for each note (each individual pipe) - one for each of the manuals - which are always right next to each other. The holes in the pipe sticks, the loops and the foundation board are arranged in such a way that, depending on the position of the loop, one, the other or none of the chambers releases the organ wind to the pipe.
The individual registers have either stops that can be pulled completely (for one manual) or only halfway (for the other manual), or register slides that are assigned to the manuals by moving a lever (left and right) ; in the middle position the register is switched off).
Double drawer
The double drawer is a type of slider drawer in which the pipes of a pedal register and the manual register are placed on a common wind chest to save space and costs. All the pipes in the pedal register are on their own playing valves, sound boxes are not necessary. All the pipes of one pitch in the manual register are on their own tone chambers with game valves. Each register in the pedal or manual work can therefore be played independently. This construction is only possible for small organs with only one register in the pedal, in which there is no need to build a separate wind chest for the pedals.
Other special designs
Advance deduction
A special form of organ register that is particularly easy to implement with the slider is the advance draw . The loop of a mixture register or a sesquialtera , i.e. a register with more than one row of pipes, has either a longer slot or two holes per pipe for one of these rows of pipes. If the associated stop is only pulled halfway, only this one row of pipes is heard at first; only when the stop is fully pulled do all rows of pipes in the relevant stop sound.
Coupling valve
A slider chest, which is built with coupling valves, has two play valves for each tone chamber, so that the registers can be played from two manuals or pedal and manual. In contrast to the twin drawer, a tone here does not have two tone chambers, but both game valves belong to a common chamber. As usual, the pipes stand over a simple loop. The drawn registers can always be played on both manuals or in the manual and pedal and cannot be registered separately for just one. The same effect can also be achieved with a paddock . Especially in the case of smaller organs with very small pedals, on the one hand there was a need to couple the pedals, on the other hand there was an occasional effort to make this technically very simple. For this purpose, the relevant chambers of a manual received a second valve for the pitch range of the pedal circumference, which is connected to the pedal keyboard.
Bass / treble division
In this design, the loop of a register is not made in one piece, but in two halves: a bass (left half of the manual) and a treble half (right half of the manual). Each half of the loop is provided with a separate register, so that, if you wish, you can play different registers in the bass than in the treble. A one-manual organ thus enables the effect of a two-manual organ.
Spring drawer
A completely different design is the spring drawer , in which there is a further valve above each tone chamber for each pipe (with mixed voices : for each tone). Above all of these small clay valves there are engravers that protrude upwards from the drawer. Above all these individual valves of a register there is a movable bar. If this is moved downwards by means of the register action, it presses the engraver and opens all the relevant valves. Since this happens against the spring force of numerous valves, the register pulls (in contrast to the sliding drawer) must be locked in the pulled state. The name of the spring drawer comes either from the fact that a register "jumps back" when pushed off again by the force of the springs - or simply from the English name for the frequently used springs, namely "Spring".
The advantage of the spring drawer over the sliding drawer is that it is insensitive to changes in the climate. However, this statement is only valid when compared to slider chests where the loops have no seals. That is hardly the case today. Therefore, the disadvantage is that the many valves represent a large number of potential sources of error.
With so-called double spring drawers, all valves belonging to one tone can be pulled out using one handle, like a drawer. This greatly simplifies maintenance.
Register drawer
In the register pulpit , all pipes in a register share a pulpit . This pulpit is supplied with wind as soon as the register is pulled. There is a single register valve for each register, whereas a play valve is required for each pipe. This results in a higher maintenance effort, which is the disadvantage of all systems with register cells. The advantage is the more stable wind supply to each individual pipe, even if many stops are drawn.
Cone drawer
The cone drawer was introduced around the middle of the 19th century. For every note in the pulpit there is a cone valve that opens a connection to the pipe (or several pipes in the case of a mixed register).
Initially, cone shops were controlled mechanically. However, each additional register increases the keystroke. That is why the pneumatic action later became widely accepted. With pneumatic control, pressing a button (in the figure: a) only opens a valve (b), which then pneumatically inflates small leather bellows under the register chambers (d), which in turn lift the cone valves (e).
One advantage of the cone chest is the simpler valve construction. With the pneumatic cone chest, the organist only has to move a small valve so that the action remains smooth, no matter how many registers are controlled. It also enabled the construction of free combinations .
The advantages are offset by several disadvantages: The pneumatic transmission causes delays. These can at best be mitigated by electrification or counter relays. In addition, the organist lacks sensory feedback with an electric or pneumatic action (the counterpressure of the keys is generated by a spring), which is why mechanical action is preferred. The cone valves also have a tendency to generate extraneous noise, which is multiplied by actuating several valves per tone.
For compositions of the late Romantic period, i.e. the time when pneumatic shutters were modern, playing on cone chest organs can be quite appropriate. This concerns z. B. the organ works of Max Reger .
Membrane and pocket drawer
This type of pneumatic drawer contains leather membranes (in the figure: e) or leather pockets as sound valves, which are pressed by compressed air (working wind, d) in front of the openings to the pipes and thus the play wind the way from the register chamber (f) into the pipe ( g) block. If a key (a) is pressed, the wind of all diaphragm valves for this tone is released. Due to the pressure of the play wind from the register chamber, the membranes open the openings to the whistle, so that the wind gets into the whistle for this tone.
At this point, one speaks of an outflow system in which a function is triggered by the flow of the wind. In the figure, an inflow system can be seen at b and c , in which the inflow of the wind triggers a function. Conical shops are therefore inflow systems. Both systems can be used on the way between button and valve. The action shown is z. B. an inflow-outflow system . Downflow systems are considered more precise than inflow systems.
Higher precision and speed are also the overall advantages of the diaphragm drawer over the cone drawer. In addition, only the membranes whose registers are switched on move and these hardly cause any background noise. The main disadvantage, however, is that all types of membranes show wear and tear and leakage over time.
Friedrich Witzig , who worked as an employee at the organ building companies Steinmeyer , Strebel and Maerz , is considered to be the inventor of the membrane box . He was the holder of a patent for this system from 1896.
Hanging valve drawer
With a hanging valve drawer, the pipe channels are supplied with play wind by a hanging valve attached to the side. This rarer type of shop was often used in Orchestrions from Welte .
Box drawer
General
In the case of the box drawer , all the pipes stand on a common large wind box that is not further subdivided inside.
The pipes are usually controlled by an electric action , forerunners were box drawers with pneumatic or mechanical action. In the case of the box drawer with an electric action, the wind supply for each whistle is controlled by its own electric solenoid valve, so each whistle is assigned exactly one valve. Only the pipes of a mixed voice can have a common valve. With this design, there is no differentiation between play and register valves. The control of the power supply to the valve for the respective pressed button in combination with the pulled register is done electromechanically. The box drawer with an electric action was indispensable in the multiplex system, but like this one could not establish itself.
Multiplex system
In an organ with the multiplex system ( unit system ), the rows of pipes stand on a box drawer with an electric action. Various registers are generated from relatively few rows of pipes through the electromechanical control of the valves in the transmission and extension process. This saves costs, space and weight. This principle can be found in many cinema organs of the 1920s and 1930s. The sound result depends very much on the individual case. Depending on the system, there are some disadvantages:
- The characteristic of the registers generated from a row of pipes is lost. The registers generated from a row of pipes all sound the same.
- The character of an organ with several parts is lost through transmissions.
- When playing several voices, there is the problem that with octave chords and fifths from the same pipe row, fewer pipes sound at the same time than with other interval chords, which means that the overall sound can appear thin and unbalanced, especially with quieter registrations. This problem occurs almost only when playing the manuals, as two-part pedal play is very rare.
- With the extension of aliquot registers from basic voices, these are not pure, but tuned equally, which is detrimental to the clarity and fusion of the sound.
From the known disadvantages, appropriate consequences for the construction of the organ were often drawn, resulting in multiplex organs with sound characteristics that were useful for their intended use.
- The number of basic voices, i.e. rows of pipes from which registers in the positions 32 '(more rarely and mostly in the pedal), 16', 8 ', 4', 2 'and 1' are generated, is not set too low. The following rows of pipes are common: Principal, flute (open), Gedackt and a bowing voice as labial parts and a trumpet as well as one or two other lingual parts with different cup lengths.
- Transmissions, especially to several manuals, are reduced to a minimum.
- The extension of aliquot registers from basic parts is dispensed with. The fifths 10 2 ⁄ 3 ′ (more rarely and mostly in the pedal), 5 1 ⁄ 3 ′, 2 2 ⁄ 3 ′ and 1 1 ⁄ 3 ′ can be generated from a labial row of fifths, and the thirds 3 1 ⁄ 5 from a labial row of thirds ′ And 1 3 ⁄ 5 ′. The same applies to the less common seventh and ninths. An exception can be made to this waiver. Since the multiplex organ is usually tuned equally, the fifths 21 1 ⁄ 3 ′ and 10 2 ⁄ 3 ′ in the pedal can be generated from a basic voice, which of course has to reach down to subcontra-C (32 ′ on key C), generated by quintextension become. In this low register, the deviation of the generated fifths by −2 cents from the perfect fifths is usually not a problem.
The sound characteristics of a multiplex organ must always be seen in connection with its intended use. A cinema organ is primarily designed for the musical accompaniment of silent films. Therefore, it should not be expected, for example, that literature from the Baroque or even the Renaissance period can be adequately reproduced on such an organ.
Ancient and medieval wind chests
In the antique organs, the various rows of pipes were arranged on a kind of register cabinet drawer. It has not yet been possible to determine whether the individual registers were used to generate different timbres or to play in different keys.
Registerless block works have been documented since the Romanesque period . All the pipes stood on an undivided wind chest. Only in the late Gothic period did the “register” reappear (voice separation) , initially implemented with the locking valve drawer, later also with the double drawer and the sliding drawer. These oldest organs also had no keys. The tones were switched on and off with the help of tone loops (clay loops) , which functioned like the register loops of the slider drawer . They were provided with return springs so that the sound stopped when the loop was released. With the introduction of the double drawer and slider drawer, the clay loops disappeared.
Check valve drawer
This windchest design emerged in the Gothic era when the medieval blockwork was initially divided into two, later a maximum of four “registers”. Each partial drawer is switched on via a shut-off valve . With the advent of the sliding chest it was largely displaced, but occasionally persisted until the 17th century.
Double drawer
This form of windchest is a hybrid between a locking valve drawer and a sliding drawer. It emerged in the late Gothic period when the division into a maximum of four registers using a locking valve shutter was felt to be inadequate. First of all, individual rows of pipes in the back set were placed on individual loops, thus increasing the number of registers. Later, individual new registers (flute, Gedackt, shelf) were added. This type of wind chest has also been largely superseded by the sliding chest.
Wind chests in harmonies
In a harmonium , the sound-producing tongues are located in the wind chest, which in this case is also referred to as a play mechanism due to the compact construction . Felted flaps over the tongues are located directly below the keyboard level and can be opened or closed using the stops, thus enabling registration (sound selection).
literature
- Wolfgang Adelung: Introduction to organ building. Breitkopf & Härtel, Wiesbaden 1991, ISBN 3-7651-0279-2 .
- Hans Klotz : The book of the organ. 14th edition. Bärenreiter, Kassel 2012, ISBN 3-7618-0826-7 .
Individual evidence
- ↑ Information on the interchangeable loop and its technology
- ↑ Roland Eberlein : A little history of the organ. (PDF) Walcker Foundation for Organ Research, p. 1 , accessed on May 24, 2014 .
- ^ Hermann Fischer , Theodor Wohnhaas : Lexicon of southern German organ builders. Florian Noetzel Verlag, Wilhelmshaven 1994, ISBN 3-7959-0598-2 , p. 475
- ^ Curt Sachs : Real Lexicon of Musical Instruments . Bard, Berlin 1913.
- ↑ Opened hanging valve drawer of an orchestrion, accessed on February 2, 2017
Web links
- Photo gallery of the Huss / Schnitger organ in St. Cosmae zu Stade with photos of a double spring drawer
- Organ portal
Winch | Gaming table | Action | Wind chest | Register | Organ pipe | brochure
