As tracker action or Traktatur at a designated one organ , the transmission system of the actuating elements of the gaming table at one end to the valve system in the wind loading on the other end. A distinction is made between the game action (also tone action ) for playing with the keyboard and the stop action for switching the stops on and off .
The game action is the connection between the keys and the pipe valves. It causes one or more whistles to sound when a key is pressed. The exact selection of the sounding whistle depends on the registration . There are different types of tone or performance actions: mechanical, pneumatic, electro-mechanical and electro-pneumatic. The different systems occur occasionally and in certain combinations next to each other in one organ.
The oldest and most original type is the mechanical action mechanism. This has a long history of development from the Gothic to the (re) built form today. The earliest key actions were not intended or suitable for fast playing and were more like today's register mechanics. With the mechanical action, each key on the keyboard is connected to the associated tone valve via various mechanical elements. The mechanics are made up of abstracts that transmit the movement horizontally or vertically by pulling them, as well as angles and waves that are grouped together on so-called wave boards and, if necessary, redirect the movement in different directions. Abstracts usually consist of very thin "strips of wood" (about 10 mm wide and 1 mm thick). At times, other materials such as aluminum or brass wire or steel braid ( cable mechanism ) were used. In the case of pressure, engravers made of thin wooden or metal rods can also be used instead of abstract ones. The waves of the wave board were mostly made of wood in the past, but iron waves are not an exclusively modern innovation either. Today, industrially manufactured steel or aluminum pipes are often used. These have the great advantage of being much more torsion-resistant than wooden shafts with a relatively small diameter, which would have to be significantly thicker. This means that corrugated boards with steel or aluminum corrugations require significantly less space than corrugated boards with wooden corrugations.
The direct mechanical connection between the key and the valve of the sound chamber gives the organist, in comparison to the other types of construction, a possibility, albeit a small one, of controlling the response of the pipes, depending on how hard and fast or soft and slow the keys are be posted. More noteworthy in this context is the fact that the real pressure point can be felt directly and does not have to be simulated. This advantage fundamentally differentiates the mechanical action from the electric action. A disadvantage of this design can be that the size of the valves and wind chests and thus the number of registers is limited as long as an organ should remain playable well and sufficiently easily. In practice, however, this limit only sets in today at a size that many organs cannot achieve. If in exceptional cases, play aids can be used to reduce the pressure point ( balancing or pilot valves ).
Although the pneumatic action became more and more popular towards the end of the 19th century, organ builders initially experimented with electrical systems. Due to its numerous advantages, the mechanical action mechanism has been the frequently chosen action mechanism again since the middle of the 20th century.
As early as 1870 , Henry Willis was the first organ builder to equip some of his organs with a pneumatic action, which in principle corresponds to a Barker lever moved from the console to the wind chest . The pneumatic action mechanism then slowly gained acceptance in the last decades of the 19th century and towards the end of that century became the most common action type for new organs, especially for larger new organs.
Several different forms of pneumatics developed over time. But they all share a common principle: The buttons themselves only operate small control valves. These let or discharge the air through long, thin lead pipes ( lead conductors). This controls additional bellows and valves that ultimately ensure that the whistles sound.
As much as this design became the standard for some time, especially for larger organs, the reasons for its gradual introduction are complex:
- Although, in the century before last, baroque organ builders saw themselves primarily as craftsmen and not as artists, they often created instruments that were excellent in terms of both sound and technology. With the later onset of industrialization, however, fundamentally different ideals applied. The organ changed from an artistic one-off to the so-called factory organ. The first steps in this direction are in the Simplifikationssystem of Georg Joseph Vogler be seen. For a simple, inexpensive and quickly built factory organ, it was decidedly easier to lay numerous long lead conductors than to build a precise and high-quality mechanical action.
- The field of music, especially church music, no longer had the high priority it had in the previous centuries. Although early forms of pneumatics in particular caused significant delays in playing, this disadvantage was ultimately accepted, especially since another advantage could only be realized with this type of action:
- The romantic taste of the time called for organs with many deep, soft and fundamental registers, which used a relatively large amount of wind. A mechanical action for such organs would have been very difficult to play, especially in the bass range. Furthermore, numerous sub- and super-octave couplers were often built during this time in order to be able to produce the desired organ sound. The pneumatic action has clear advantages in this respect, both technically (simple production) and in terms of playing (easy variety).
The biggest disadvantage of the pneumatic action is the (sometimes very long) delay between pressing a key and speaking to the whistle. The problem of the delay was particularly serious with the first designs, which were based on a supply air principle : By pressing a button, air flows into a bellows or an inflatable membrane. This actuates one or more additional valves that ultimately allow the pipe wind to flow into the pipes. Later improved forms of the pneumatic action were based on the relief or wind outlet system : In the case of the diaphragm or pocket drawer , the pipes stand on pipe sockets that are closed by an inflated membrane or pocket at the lower end located in the wind chest. Only when a key is pressed does this membrane or pocket collapse and allow the pipe wind to flow through the pipe socket into the pipe concerned. With this system there must inevitably be a wind turbine that provides wind of different pressure. If a whistle is to sound, it is even very beneficial for this principle to function quickly if the membranes are (also) compressed by the “whistle wind” acting on them. If, on the other hand, pipes are not to sound, the membranes must remain inflated - against the whistle wind acting on that part of their surface. The wind supplying the pneumatic action must accordingly have a sufficiently higher pressure.
However, this does not completely solve the problem of delay. With well-maintained exhaust systems, this is noticeable, but not dramatic. There are reports (which are no longer verifiable today) about bad, worn tractors that the delays could last almost up to a second.
Although the delay increased with the distance of the console and thus the length of the lead conductors, with the pneumatic action it was also possible to a reasonable extent to build free-standing console tables that could stand a few meters away from the organ.
A major component of every pneumatic action is a large number of small bellows, pockets and / or membranes. Depending on how accessible these were installed in the wind chests, there could be problems with maintenance or repair. A very particular disadvantage, however, was that these components were quite prone to failure and often had to be completely replaced after a few decades (a solid mechanical action can last for several hundred years.) The lack of a noticeable pressure point when a key is pressed is another disadvantage of the pneumatic action.
See also: Barker lever
With the advent of electrics at the end of the 19th century, the pneumatic actions were partially supplemented by electrical elements. Initially, electrification was associated with the problem of finding a pleasant and soft game. The construction of the contacts at the turn of the 20th century initially required a pneumatic control in the gaming table, the small bellows of which operated the contacts. With the invention of long, break-proof key contacts made of fine silver, this construction became superfluous around 1910. The contact was now made directly from the buttons, the electrical impulse is transmitted through a cable with a small cross-section to an electromagnet with built-in spark extinction . The action path can be almost infinitely long and complicated, and organs could be equipped with mobile console tables. From then on, remote control units could be played with almost no technical delay. The connection of electrics and pneumatics is particularly suitable for membrane and pocket drawers as well as cone drawers, whereby the relay valve is then electrically controlled.
There are various advantages over the purely pneumatic and purely electric action. By installing a pneumatic pre-relay, you save per tone when charging a tone chamber with electromagnets. While with an electropneumatic action only a single magnet per tone and wind chest is necessary to activate the pneumatics, which then lifts all valves together, with a purely electric chest you need one electromagnet per cone. Consequently, for practical reasons, cone shutters are usually never purely electric, but always in combination with pneumatics. An affordable, reliable and fireproof power supply for a large number of powerful electromagnets has not been available for a long time. The tasks of the action were therefore divided up as follows: Solely overcoming the path between button and valve as well as coupling options, which does not consume a lot of energy with downstream pneumatic relays, was done electrically and therefore without delay. The force and energy-consuming work, namely opening the pipe valves, was still done pneumatically.
The electro-pneumatic action is also shortened and misleadingly referred to as "electric".
A purely electrically controlled organ was built in France as early as 1852, but in 1863 Walcker in Boston and also in 1878 Weigle at the World Exhibition in Paris had not yet solved the problems with contacts and the power supply by batteries in a practical manner, which is why the pneumatic action was built first. Since around the middle of the 20th century, organs have occasionally been equipped with an electro-mechanical action. Under each play valve there is a small electromagnet that opens the valve . The system is absolutely necessary in connection with the rare box drawer and is otherwise almost exclusively used in the sliding drawer. The electro-mechanical action works almost instantly and can control valves of any size.
The so-called electric action was particularly often installed or even indispensable on the multiplex organs . From an extremely small number of rows of pipes, each with a significantly larger pitch range than the normal 4 1 ⁄ 2 octaves, numerous registers in a wide variety of foot pitches were "picked out". Such a complex, but also (depending on the number of activated registers) optionally flexible connection between the keys on the one hand and the valves on the other hand is only possible with the electro-mechanical action.
Even if the mechanical version is in the foreground nowadays, especially in the area of the game mechanisms, almost all larger new buildings (especially for concert halls) have a second (mobile) electrically connected console, or even a few works that cannot be accessed via abstracts. In addition to the transmission by radio or fiber optics , the changeover from binary control technology to digital control technology is currently the greatest innovation in the field of control of the sound valves. The use of digital control technology enables all conceivable real-time processing, from simple transposing to complex special coupling , as well as the use of MIDI systems for the complete control of the instrument from the outside, as well as for recording and thus later playback of the organ playing.
The electromagnetic opening process of the valve cannot yet be influenced by the player and also not felt, since without a mechanical connection there is no transmission of the pressure point. However, research is being carried out into how the interactive behavior of a mechanical action can be mechatronically simulated.
There are occasionally mixed forms in the following cases:
- Due to the distance to the main organ, remote control units can almost always only be controlled electrically.
- In order to avoid playing too hard when many paddocks are switched on, the paddocks are occasionally built electrically or, rarely, twice, both mechanically and electrically, for the player's choice. This alleviation of the variety is gaining in importance, now that sub- and super-octave couplings have also been built more and more frequently.
- Individual stops are either placed far away from the associated wind chest or even completely outside the organ, either for reasons of space (e.g. 32 'stops) or for acoustic reasons (e.g. tuba). In practice, the control of these individual registers only makes sense through box loading with electric valves.
Regardless of this, sometimes very large organs have to be equipped with a second, more distant, even mobile console . This can also significantly expand the liturgical usability of a church organ. Such organs often have a console with a mechanical action in the main body of the organ, while the second console, which may be mobile, can only be implemented electrically. In the case of organs that are aligned in this way, the reason is less often that both gaming tables should be played at the same time. Nevertheless, the presentation of music for two organs is possible, perhaps with the aid of technical hearing aids. The console with its electric action can also be used to play other “ancillary organs” in a church. As far as it is not z. If, for example, it is an echo work above the church vault, these “side organs” usually also have their own, ideally mechanical console.
The register action or registry has the task of transmitting the switching impulse from the console to the wind chest, so that the device of the wind chest is activated to "switch on" or "switch off" the desired registers.
Instead of the box load , cone chest , diaphragm load and the spring chest that most of the organs built today sliderchest , whether in mechanical or electric action. In all these cases, the register action is either the mechanical connection between the register pulls and the loops or the electrical connection between the register pulls , register rockers or register buttons and the loop pull motors or loop pull magnets. With mechanical cone chests and organs with pneumatic action, a wind control influenced by the stop ensures whether a stop sounds or not. This could be done in a very simple way (e.g. pneumatic cone drawer ) or in a technically very complex way ( Pitman drawer ).
As with the game action, there are different types of stop action:
With the mechanical stop action, a mechanism consisting of tie rods and shafts is moved by pulling or pushing back a stop, which causes the loop in the wind chest to be shifted and a certain stop of the organ can be played. In the past, tie rods and shafts were made almost entirely of wood. The shafts in particular then had to have a relatively large diameter (about 5 cm or more) with a greater length to achieve the necessary torsional rigidity. Therefore, metal shafts are often used today, which are just as torsion-resistant with a significantly smaller diameter.
The pneumatic stop action was invented by Cavaillé-Coll . He realized them on his two largest organs in Paris in St-Sulpice in 1863 and in Notre-Dame in 1866. Two bellows, roughly the size of a hand, which are controlled alternately, move a loop of the slide box . So you occasionally replaced a complicated Trakturwegsführung and also wins ways to set up Game Aids as the Crescendo and later the free combinations . In a general sense, the pneumatic stop action is found today in many historical organs of the 19th century, then mostly in connection with cone chests : In this case, the stop is activated with the help of a single bellows. At the moment it is almost no longer built, as is the electro-pneumatic stop mechanism, which is often found in combination with pocket and membrane drawers. In the 1940s-1960s, a pneumatic register control was also occasionally built on neo-baroque slider-chests, as was the case in the early days, because the corresponding electrical systems were not yet reliable enough. Due to the provision of series-ready magnets and motors for the loop movement, this type of construction was finally forgotten in modern organ building.
With the electrical register action, this process is controlled electrically, which has the advantage that registration aids such as free combinations - often in connection with a sequencer - can be used, which allow register combinations to be pre-programmed. Are often here instead of the usual drawstops also register paddles or register button used. An electromagnet (loop pull magnet) or electric motor (loop pull motor) is activated, which moves the loop in the slider drawer; In most cases, this is counteracted by a magnetic brake, which is supposed to ensure noiseless movement of the loop and slows it down at the end of the process, so that annoying rattling and beating is dampened as much as possible.
There is also a change in the electrical register action, from analog to digital signal transmission. The arm-thick cable strands, each with a power cable for each button and each switch, have now given way to commercially available network cables , optical fibers or even radio transmission. Mobile electric gaming tables can sometimes be connected to the organ at several points in the room by simply plugging them in. Complicated circuits are also possible, such as B. the register fetter , which has already existed in a few pneumatic register actions.
With the double register, a fully functional mechanical action can also be controlled electrically with the help of loop magnets or loop motors. In this way, electronic playing aids can also be implemented with an actually mechanical stop action. The disadvantage of this double system is a somewhat more forceful manual operation of the mechanical stop action, since the loop pull magnets or loop pull motors have to be moved with it.
- Wolfgang Adelung: Introduction to organ building. 2nd revised and expanded edition. Breitkopf & Härtel, Wiesbaden 1991, ISBN 3-7651-0279-2 (2nd edition, 2nd revised and expanded edition, ibid 2003).
- Hermann J. Busch, Matthias Geuting (Hrsg.): Lexicon of the organ. Organ building - organ playing - composers and their works - performers. Laaber-Verlag, Laaber 2007, ISBN 978-3-89007-508-2 .
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- Klotz: The book of the organ. 2004, p. 34.
- Klotz: The book of the organ. 2004, pp. 37-38.
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- Klotz: The book of the organ. 2004, pp. 103-104.
- Klotz: The book of the organ. 1988, pp. 36-37.
- Walter Ladegast (Ed.): Friedrich Ladegast; The organ builder from Weissenfels. Weidling Stockach, 1998. ISBN 3-922095-34-8 . P. 84.
- Klotz: The book of the organ. 2004, p. 38.