Hammond organ

The Hammond Organ ( Hammond also short ) is a named after its inventor Laurens Hammond electromechanical organ.

Originally intended as a substitute for the pipe organ, it was about the use as an entertainment tool to the instrument of jazz; in an affordable substitute for pipe organs in American churches began to use them in the gospel music. From there, the Hammond organ in rock, rhythm and blues, soul, funk, ska, reggae, fusion spread. However, as a full substitute for pipe organs, the Hammond organ could not be established.

Greatest popularity it had in the 1960s and 1970s; then came the mainstream hardly a band without organ. But even today her distinctive sound or imitation of this sound in popular music are widespread. Over the decades, the Hammond organ (especially the B3 model in conjunction with a Leslie speaker system ) to an established instrument.

All instruments in common is the construction with two manuals and pedal. However, range of manuals and the pedal are different in the various models. The upper manual is called Swell, the lower manual as Great. These terms are borrowed from the pipe organ, meaning there Hauptwerk ( Great ) and swell ( swell ).

  • 3.1 bars, and footages
  • 3.2 Harmonic foldback
  • 3.3 Chorus and Vibrato
  • 3.4 Percussion
  • 3.5 effects
  • 3.6 presets
  • 4.1 The main models


Laurens Hammond, himself a musician, invented around 1920 he produced watches for an AC synchronous motor. From 1932 on, he sought other possible applications for this engine. Was a result of the boom of theater and cinema organs and stimulated by a company employee, the organist of a parish, came to him in 1933, the idea to construct the sound generating principle of the Hammond organ. Numerous experiments with a piano meant that he applied on 19 January 1934, this instrument a patent. On April 24, 1934, he was from the U.S. Patent Office in Washington, DC the patent for the packing box prototype under the name Electrical Musical Instrument awarded (U.S. Patent 1,956,350. ) The organ was on April 15, 1935 by organist Pietro Yon at a press screening in New York's St. Patrick's Cathedral to the public presented. Henry Ford issued shortly after an order for six organs. Other prominent purchaser were George Gershwin and Count Basie. Over the years, the organ became a characteristic of certain styles of music instrument, mainly in connection with the Leslie speaker cabinet, in which the sound using rotating reflectors a floating effect is obtained ( invented by Donald Leslie ). Since 1936, the instrument has been offered successfully in Germany in competition with Edwin Welte's ultimately unsuccessful Lichttonorgel.


The tone of the Hammond organ begins in the so-called generator. This rotating steel tonewheels ( " tonewheel " ) with a wavy edge against electromagnetic pickups (permanent magnets in coils). Removed by the waveform and the edge of the wheel approaches the periodic permanent magnet. This changes the magnetic flux thereby induces an alternating voltage in the coil. Due to the shape of the teeth results in a sine-like oscillation. This is smoothed by a filter circuit on, so that an almost ideal sinusoidal shape. The AC voltages generated in the order of a few millivolts are then passed through the manuals, drawbars and the scanner ( vibrato and chorus circuit ). At the end of the processing chain is an amplifier stage which amplifies the audio signal so far, that a speaker can be driven.

The generator contains 86-96 tonewheels different numbers of teeth. These are driven by a synchronous motor, which has to be taken to start with an auxiliary motor to approximate synchronous speed. After booting to approximate synchronous speed, the speed of this motor is only dependent on its pole pairs and the mains frequency. This can prove to be a disadvantage when the electricity from generators is not stable in frequency at an outdoor event. The drive motor is resiliently connected to the main shaft by a fly wheel spring system to drive them from the harsh ( the torque is not constant throughout a revolution of the motor ) to decouple. To decouple mechanical noise are both resiliently suspended in the housing.

Building and maintaining

The tone wheels sit on several ( 48 in the console and 42 at the Spinettmodellen ) steel shafts that are mounted in bronze bushings. Forwards and backwards, the magnetic cores of the cartridges projecting from the housing of the generator, which is about half as wide as the whole organ. About the distance of the magnetic cores to the respective tonewheel the volume of the individual sounds can be adjusted. The tone wheels do not sit on the pitch chromatically sorted along the main shaft, but are arranged in chambers of four pieces with the same ratio. Two of these chambers for a total of eight tone wheels that produce different octaves of the respective tones. Via the wiring ( Verharfung ) the sounds with the contacts of the local keys are connected. The signal level is a few tens of millivolts.

The bronze bearings require continuous lubrication. This is ( wick ) secured by a leading to each storage cotton thread which sucks oil by capillary action from a centrally along ( parallel to the shafts ) running on top of the tone generator oil groove. The groove (and the scanner vibrato ) is filled via two small hoppers from above with oil. At least once a year to suitable oil to be refilled, so it is a few mm high in the hoppers.

The engine tone generator unit is suspended for acoustic decoupling spring in the housing of the organ. At delivery, and in larger transports but a transport lock is to be fitted, similar to other devices with spring- suspended masses (turntables, washing machine). A tilting of the instrument is not a problem. However, it should be noted with respect to the oils that in the oil pan of the felt located there only is wetted. Under no circumstances may stand in the bath oil. First, it would overflow when tilting the organ, on the other hand would be an "over oiling " damage the vibrato scanner.


In models that are operated with 60 Hz line frequency, a four-pole motor with 1500 rpm runs a six pole motor with 1200 rpm (20 Hz), in 50 Hz models (25 Hz). The speeds needed for sound generation are provided by gear transmission with twelve different translations. The resulting twelve different speeds at which the tone wheels rotate on the Tonradwellen, give approximately the twelve equally- tuned chromatic tones of an octave.

Using the example of an organ, which is operated at 60 Hz mains frequency and 96 tone wheels and 61 keys (C- c4 ) per Manual has, the ratios will be explained in more detail: At 60 Hz line frequency, the motor shaft of the six-pole synchronous motor rotates at 20 Hz following table shows for this case the twelve translations of the gear train, the corresponding notes of the lowest octave of the organ ( double octave keys C to H when disconnected from 16' - bolt ) with their frequencies and the deviations from the equal- mood:

The organ is tuned to concert pitch a1 = 440 Hz.

Pro translation, a set of eight tonewheel with different number of teeth rotates on four Tonradwellen ( two tone wheels mounted on a shaft, with which they are elastically coupled ) to generate the different octaves of tones:

The five- octave come from technical reasons, no tone wheels with 256 teeth used. On the Tonradwellen for the tones C to E are toothless wheels without pickups, which are mounted only for mechanical reasons. Therefore, an organ with 96 tonewheel has only 91 tone wheels, each of which produces a sound. The tone wheels with 192 teeth for the sounds c5 to fis5 are on the Tonradwellen for the notes F to H. The ratio 192:256 teeth is equal to 3:4, which corresponds to a perfect fourth. Therefore, the tone wheel produced with 192 teeth on the Tonradwelle for the tone F, the lower fourth to the sound f5, c5 so the tone. But as the perfect fourth is different from the equal- fourth and in addition other variations come through the translations added, are obtained for the five tones of the octave other deviations from the equal- Mood:

All deviations from the equal temperament tuning described here below two cents, which is generally regarded as perception threshold for upsets. Thus, the combination used in gear drives and tonewheel a sufficiently accurate approximation for the musical practice of the equal temperament tuning dar.

The rigid mechanical specification of the frequencies of the different number of teeth of the wheels, the organ can not tune in itself, but varies the pitch of the instrument as a whole with the mains frequency. A Hammond organ can thus agree in any way; all other instruments have to depend on her. ( This situation can create a retrofitted frequency converter, which is available in specialty stores. )

Around 1975 ended the production of the Hammond organs with electro-mechanical tone and put on organs with electronic sounds up by. However, these organs were the typical sound of the electromechanical organs initially not reach, so that they were not accepted properly by professional musicians.

Sound shaping

The following considerations apply to the well-known model B3, other models show differences to without changing the basic principle.

Drawbars and footages

A sound of the organ is made up of nine different frequencies, the volume level of the so-called drawbars ( Drawbars engl. ) can be set (see also additive synthesis ). We call this organ therefore as neunchörig. Each drawbar has nine different loudness levels ( 0-8 ). This results in the calculation, since the zero position of all drawbars does not result in sounding combination, 99-1 = 387 420 488 different possible combinations.

The drawbars are arranged for ergonomic reasons, so that sit at the game with the right hand on the upper manual drawbars left because they are operated with the left hand. Drawbars are mounted on the right side of the lower manual.

The drawbars are labeled according to their pitch, expressed by the so-called drawbars. This division was taken over by the registers of the pipe organ. The drawbars are ( in the unit of foot, ' ) 16', 51/ 3 ', 8 ', 4 ', 22 /3', 2 ', 13/ 5', 11/3 ', 1'. They correspond to the following intervals or overtones based on the base 8 ' ( Äquallage ):

A distinction between the root and its octaves ( footages 8 ', 4', 2 ', 1', white drawbars ), and lying between the octave overtones ( footages 22/3 ', 13 /5', 11/ 3 '; black drawbars ). Next there is Subtöne ( footages 16 ', 51/ 3'; brown drawbars ). The Subtöne not belong to the harmonic overtones of an 8 -foot register.

In a pipe organ all Obertonregister are always pure, ie, with frequencies forming an integral multiple of the fundamental frequency, running. Hammond in this only for the octaves (8 ', 4', 2 ', 1', based on 16 ' ) holds. To fifths (51 /3 ', 22 /3', 11/ 3 ') and the third (13/ 5') to build such were for the fifths tonewheels {6; 12; 24; Teeth ...} and for the third tone wheels with { 20; 40; 80; ...} Teeth required, which are not present, however. The fifths and the third must be obtained from the existing tones, but they are approximately equally- voted. This type of Fußlagengewinnung represents the extreme case of a multiplex organ corner shows footages ( " Register") are obtained from a single series tone generator. The following table represents the sounds and their deviations from the perfectly tuned overtones for the drawbar 22/3 ' ( fifth, 3rd partial ) and 13 /5' ( third, fifth partial tone ) is:

Note: Because the penny is a relative measure of the distance between two tones or frequencies, the values ​​of the deviations in the 22/3 apply ' for the drawbar 51/3 ' and 11 /3 '.

While the variations in fifths still be in the range of the perception threshold for upsets, so the variations in the third clearly as deviations from the perfectly tuned major third ( fifth partial tone ) are perceptible, which can feel pipe organ player to be very disturbing. On the other hand, carries this peculiar type of Fußlagengewinnung to the typical sound of the organ.

As a notation, tab settings, the positions of the registers are represented by nine digits in notes or relevant literature. So does the representation 888888888 about that all the stops are pulled maximum. In 500008000 sound only the 16' - and 2'- register. Often the numbers are also grouped according to the scheme 2-4-3, so that some organists 88 888 8888 or 50 000 0008 record for the above examples.

Harmonic foldback

The 91 frequencies of the generator is not sufficient to supply all the buttons with the entire overtones. These 121 frequencies ( low C to c8 ) would be necessary to have some high-pitched sounds are missing. Now if you played a high note, its higher harmonics not erklängen why he sounded quieter and thinner. The so-called harmonic foldback counteracts this effect. If a harmonic is outside the scope of the generator frequency, it sounds an octave lower. The harmonic foldback is required from the tone g5 because the highest available sound of the organ is fis5. Thus, the frequency characteristic of the high notes will change significantly. The harmonic foldback is the reason why a B3 in the high altitudes screams so. For the harmonic foldback situation is as follows:

Functionally, the harmonic foldback a Oktavrepetition in a Pipe Organ Register. However, there is a significant difference to the pipe organ. Repeats at a pipe organ, a 2'- register on the key g3 in the 4'- position, so own pipes are also available for the highest keys. Along with a 4 'stop words resound 4' 2 'and from the key g3 4' 4 ', ie two notes simultaneously on each key. Since no tone wheels are duplicated at the Hammond organ sound only to the key fis3 two different tones simultaneously, namely 4 ' 2', from the button g3 but heard only one sound, the 4 ' - but is also here this a sound then made available twice, resulting in the mixture ( at least in theory ) gives a volume increase. Especially when combining 4 ' 2 ' 1 ' is the tone in the high register but increasingly thinner. Harmonic foldback therefore solves the problem of the height thinner sound not exhaustive.

Chorus and Vibrato

A chorus effect is nothing more than a beat in principle. This usually arises when two tones resound with very slightly different frequencies. By 1940, it still reached at Hammond organs by a second tone generator, the so-called chorus generator, einbaute, who was very slightly out of tune compared to the main generator. The frequencies of this additional generator were superimposed with those of the main generator, resulting in a chorus effect resulted. Since the so -equipped organs were overly difficult, you later went on to install a so-called scanner vibrato:

Vibrato unit comprises an analog delay line ( or phase shift circuit → cascaded LC and LRC filter circuits ) 16 outputs, to which picked off the stage by stage increasing delayed sound signal and is supplied to the vibrato scanner. This is a kind of contactless rotary switch ( technically similar to a variable capacitor 16 and a rotor stator packs package). The voltage applied to the stator packs, each to varying degrees delayed signal is picked up and passed on by the rotor.

The phase-shifted signals are specified with at the ascending and descending delay ( corresponding to the pattern 1-2-3-4-5-6-7-8-7-6-5-4-3-2-1 ) on the stator cores. A periodically varying degrees delayed signal for further amplification is thus given over the coupled to the motor shaft rotating rotor. This initially results in a flutter ( vibrato ) of Orgeltons. If you mix this vibrato signal with the signal unchanged, what happens on the effect size rotary switch, there is a special chorus effect, which is known by countless Hammond recordings.


The percussion tab is only available on the upper manual, and only on one of the two DRAWBARS. The sounding and rapid decay of a foot position gives the percussion effect. The percussion does not sound at every keystroke, but only if preceded release all keys. The drawbars of 4 'and 22 /3' are connected as a percussion register, with a short ( about 200 milliseconds) and a long ( a brief second) decay time can be selected. In addition, the volume between normal and Soft is switchable. To control the percussion of 1'- key contact is used, the 1 ' Drawbar is so dumb with activated percussion.


Hammond organs were often equipped with a spring reverb to give your sound more space. In addition, the sound of the Hammond for many is inextricably connected to the Leslie. This so-called Motion Sound system is based on the sound of rotating speakers (Doppler effect), which causes the familiar wail of sound. Curiously, Hammond organs were not equipped from the factory with a Leslie connector, as Laurens Hammond did not like the sound of the Leslie. This had to be retrofitted with a Leslie connector kit rather. However, reduced Leslie speakers were installed in the T- and M- models from 1967.

The Hard Rock was and still is common practice to reinforce Hammond organs on guitar amps. Models from Marshall are popular and widespread. Jon Lord coined in the 1970s, this style sound.

Other effects that are used to change the sound, are phaser, ring modulator and flanger.


In addition to the drawbars offer some models called presets, allowing defined by the manufacturer registrations can be accessed by pressing a key. Larger organs such as the B3 offer on both manuals to a full octave of inverted - colored buttons with which the user presets can be selected. You can only have a preset be selected at a time, the button then locked in the depressed position. The drawbars pretend not automatically because it lacks an engine, the presets are rather internally wired.

Other models offer toggle switch on as presets. These include the M-100 and L-100 series of Hammond.

Model types

One distinguishes two basic types of Hammond organs:

  • Console models: These have two manuals, each with 61 keys (C- c4) and a 25- Töniges (C- c1) or 32- Töniges (C- g1) Bass Pedal (full pedal ). Furthermore, four neunchörige DRAWBARS (two per manual ) and nine presets per manual are available. ( The inverted color keys at the left end are manual switches, are the selected presets and DRAWBARS ). The bass pedal has two drawbars (16 ' and 8'). Console models were intended for the concert and church music field. To them, the technically similar model lines A100, B3 and C3, and RT3, D100, E100 and H100 counting ( list incomplete).
  • Spinettmodelle: You usually have two manuals, each with 44 keys ( F- c3 ), a Drawbar per manual, no or few presets and a twelve-note (C- H) or dreizehntöniges (C -c) stub pedal. The lower manual is only seven or achtchörig, the subharmonic register ( 16 'and 51 /3' ) are missing. Spinettmodelle were designed for the home. The most important members are the L100 series, M3, M100 and T100.

The console models also feature the "harmonic foldback ," which is not found in the Spinettmodellen. This results in each case, basic tonal differences between the two model types.

The most important models

  • A100 ( 1959-1965 ), B3, and C3 ( 1955-1974 ): The epitome of the Hammond organ. Sound production and sound design are identical for these models. The tone generator 91 generates frequencies. All have two manuals à 61 keys, the left of which eleven more, reverse -colored keys. For nine on a clipboard hardwired presets and two DRAWBARS per manual, a 25 - Töniges bass pedal, percussion, scanner vibrato and reverb The A100 was designed for home use, it is in contrast to the B3 and C3 in addition a spring reverb system, two power amplifier ( main amplifier with 15 watts and reverb amplifier with 12 watts of output power ) and three speakers ( 2 x 12 " for the main and a 12" installed speakers for the Hall amplifier). The B3 is the concert model and the C3 model of the church. They differ only in cabinet construction and are technically identical.
  • M3 ( 1955-1964 ): The also "Baby B3 " called M3 is a Spinettmodell with two manuals of 44 keys and 12 -note pedalboard. The generator 86 generates frequencies. It has nine drawbars for the upper manual, eight for the lower manual and a Basszugriegel (16 '), as well as percussion and vibrato scanner. A special feature is the eighth drawbars for the lower manual, which leaves the third ring out over the 1'- register, so a 4 /5 ' register. The M3 has no presets, but a built-in 12 - watt amplifier and a speaker.
  • M100 ( 1961-1968 ): This is a further development of the M3 dar. additionally, you still has presets, reverb, some auxiliary switch for chorus effects and a 13 - Töniges bass pedal. The built-in amplifier drives two speakers, and there is a third speaker for the reverb effects. Nevertheless, the M3 is the better tool for many organists, as the M100 does not have a so-called waterfall keyboard like the B3. A well-known example of the use of the M100 is the hit A Whiter Shade of Pale Procol Harum by.
  • L100 ( 1961-1972 ): The organ used by Keith Emerson. The L100 was the " cheap spinet " of Hammond. It is technically similar to the M100, but has, in contrast to the latter no scanner vibrato and only seven drawbars for the lower manual. A variant is the P100, a L100 in a transportable ( two-part ) housing.
  • T200: two manuals with 3 ½ octaves, not ( inverted ) preset buttons, 13töniges bass pedal. In the base of the housing, a mechanical Leslie is installed. The model without Leslie was called T100, of which there was also a portable version. This was then TTR 100 A significant difference with the other mentioned Hammond models is that the T-Series amplifiers operate with transistors. Due to the non-existing tubes, the organ can not so nice distorted / be overridden, as we know it from the other models.

Hammond organ today

Successor and owner of the name Hammond is a Japanese company called Suzuki (not to be confused with the motorcycle manufacturer), the modern under the company name Hammond Suzuki organs of the brand Hammond in the old style and sound markets. In these, the sound of the tone generator is simulated by digital technology. The German distributor in Setzingen at Ulm maintains, however, at the same time a specialist workshop for the repair of the old models; large sales room are also original Hammond organs.

Also, some foreign manufacturers offered and offer keyboards and sound modules with the Hammond sound and controls on, including the company Clavia ( with the models Nord C1, Nord C2, Nord C2D, Nord Electro, Nord Stage ) KORG (CX -3, BX -3, CX-3 and BX-3 II II), Roland, Oberheim and Kurzweil, partially achieve a remarkable authenticity of the sound.

There are also under whose computer programs, some of which also the sound and - about using special drawbar adapter - try to imitate the playability of Hammond organs; the most famous one, the software company Native Instruments Vintage Organs.

Hammond - Suzuki himself sets a certain emphasis on Organs (Model 935, A- 405 and 920). In addition, series are offered with home organs ( wooden case with horseshoe table ), the small, mobile and modular, expandable XK series and as a volume model, the visually and acoustically based on the B3 B3 MK 2. All models are based on the digital imitation of the tone wheel generator sound.

Problems of sound synthesis

Despite the modern digital technology succeeded and succeeds only with difficulty, to produce the sound of an old, electromechanical Hammond organ electronically (ie, "artificial" ) and to reproduce. For this reason, the old electromechanical organs still enjoy great popularity. The reasons for the heavy Nachahmbarkeit inimitability or the sound of the electro-mechanical tone are mainly the following:

Hammond organ music

Musicians, in which the Hammond organ was formative or: