The Hammond organ is an electric organ, invented by Laurens Hammond and John M. Hanert and first manufactured in 1935. Various models were produced, which originally used tonewheels to generate sound via additive synthesis, where component waveform ratios are mixed by sliding switches called drawbars and imitate the pipe organ's registers. Around 2 million Hammond organs have been manufactured, and it has been described as one of the most successful organs ever. The organ is commonly used with, and associated with, the Leslie speaker.
Tonewheel organs Tonewheel organs generate sound by shaped mechanical wheels, that rotate in front of electromagnetic pickups. Each tonewheel assembly creates tones with low harmonic content, close to a sine wave. Inside the coil is a permanent magnet. As the profile of the tonewheel pass by, the strength of the magnetism changes—when the highest part is closest to the tip of the magnet, the magnetism is strongest. As the magnetism varies, an alternating current (AC) is induced in the coil, producing one of the frequencies used in harmonic synthesis. ImageModel Name / NumberYears producedDescription A 1935–1938 The first Hammond in production. Two 61-note manuals, 25-note pedalboard, 2 x 9 drawbars per manual, 2 pedal drawbars, 9 presets per manual, a tremolo effect generator ("tremulant"). A-B 1936–1938 /1942 After the introduction of Model B-C in 1936, previous Model A was available as Model A-B. / B series actually starts with Model A-B. B-C 1936–1942 The first organ produced in the deeper Model B cabinet, to accommodate the chorus generator B-A 1938 Model B-C style organ with built-in player organ mechanism (possibly Duo-Art), custom built by Aeolian-Skinner.. – Two manufacturer plates can be confirmed : one is "Hammond Organ Mechanism Model BA" by Hammond Instrument Co., and the other is "Aeolian-Hammond Player model BA" by Aeolian-Skinner organ Co. BV 1946–1949 Same as Model B-C but with the Hammond Vibrato and Vibrato Chorus. Model B-C itself could be converted to the Model BCV by installing these units. B-2 1949–1954 Model B style cabinet with Selective Vibrato (vibrato available on either manual independently). B-3 1954–1974 The best known Hammond. Similar to the B-2, but with added Touch-Response Percussion Control. Made famous by Jimmy Smith who influenced numerous other players. A-100 1959–1965 Same tone-wheel generator as the B-3 / C-3 but with power amp and speakers built into the console, along with a separate Reverb amplifier and speaker. C 1939–1942 Almost same as Model A-B but with church style cabinet. CV 1945–1949 Based on Model C, Hammond Vibrato was added. Similar to the B-V, but without a chorus generator, and with in a church style cabinetry. C-2 1949–1954 Identical to the B-2 except for cabinetry (Tudor-style "closed" cabinet). C-3 1954–1974 The second best known Hammond. Identical to the B-3 except for cabinetry. D 1939–1942 A model C organ with factory supplied chorus generator D-100 1963–1969 Internals of an RT-3 with built-in amp and speakers E 1937–1949 The first Hammond Organ with a 32-note American Guild of Organists (AGO) pedalboard. Also included toe pistons, a Great to Pedal coupler and separate Expression Pedals for Swell and Great Manuals. E-100 1965–1970 A self-contained organ somewhat similar to the A-100 except for: One set of Drawbars per manual instead of two, Preset Tabs replace reverse-color Preset Keys, Percussion Voices with Reiterate instead of harmonic percussion and added Harp Sustain and rhythm effects (Cymbal and Brush) for Lower Manual and Pedals. E-200 1965–1971 A version of the E-100 specifically designed for churches. Liturgical Preset Tabs, no Cymbal/Brush or Reiterate on the Percussion which plays from the Lower Manual. E-300 1965–1969 A lower-cost version of the E-100. Celesta substituted for Harp Sustain in the Percussion section. G 1941–1944 /1946 Almost identical to model D, except for the side handles for transportation. Model G means US Government model to use on US Army and various recreational service facilities. Supplied with tone cabinet G-40 (B-40 with an extra reverb unit).:
Two models in Church-styled cabinet were made under military specifications, and named G (G for "Government contract", with chorus), and G-2 (with vibrato), to be installed in chapels and officer's messes of U.S. Army and Navy.
Later, Government model was taken over by model C-2G (1952-1953) and C-3G (1955-?). G-100 1964–1967 Non-drawbar tone-wheel organ built completely to AGO specifications. Included 65 stop tablets, 12 couplers, 18 thumb pistons, 8 toe pistons. Also known as the Grand-100. H-100 1965–1969 Deluxe self-contained tone-wheel organ with extra tonewheels for higher pitched tones. Also included reverse-color Preset Keys, Mixture Drawbars for additional harmonic, String Bass (pedal sustain), Stereo Reverb and stereo chorus and vibrato scanners. 50 Watts of three-channel amplification. H-262 1969–1975 Version of the H-100 designed for churches. HX-100 1970-1975 Version of the H-100 in an X-66-style case for stage work. Supplied with D10 speaker. L-100 series 1961–1968 First Hammond to retail for under £1,000. L-100A Same as L-100 but with additional Percussion voices such as Guitar, Banjo, etc., alternating reiteration on Xylophone and Marimba and rhythm effects (Cymbal and Brush) for the Lower Manual and Pedals. L-200 Included built-in Rhythm II rhythm unit. Porta Bseries 1971–1974 (1970) Portable version of L-100 series for professional use. There were several versions on each country, built by different factories: L-100NS / L-PNS-100 – USA version (LP-100 ?) L-100-PN / L-100PNS – Belgian version, also sold in Netherlands. S means a version with pedal sustain. P-100 / L-100-P – converted L-102, sold in Germany and Denmark. P-100-S – a version with pedal sustain (1972–1974) P-100-H M 1948–1951 First spinet organ. 2x44 key manuals, 12 note pedalboard. M-2 1951–1955 An M with Selective Vibrato (Vibrato available on either Manual separately). M-3 1955–1964 Same as M-2 but with Touch-Response Percussion Control. M-100 1961–1968 Tone-wheel spinet organ, replacing the M series. Added features include Presets, Vibrato Celeste and Stereo Reverb. Also the Legato Pedal control is controlled by a tablet, replacing the foot switch on the M-series organs. R-100 1970–1975 Retrieved 5 August 2013. Self-contained organ based on the E-100 but with transistor / solid-state power amp, built-in Leslie (no scanner vibrato) and Pedal String Bass. RT 1949 Replacement for the Model E. Similar cabinet style to models C and D but with 32 note AGO pedalboard and electronic Pedal Solo Unit. RT-2 1949–1954 Similar to RT but with Selective Vibrato. RT-3 1954–1969 Same as RT-2 but with added Touch-Response Percussion Control. T-100 series 1968–1975 A tonewheel spinet with a transistor / solid-state power amplifier TTR-100: portable T-100 produced for the European market. T-200: T-100 with built in leslie and extra percussion. T-400: as T-200 but with Drum machine. T-500: as T-400 but revised case.Last tonewheel built. XTP: Futuristic T-500 with pull out speakers leaving organ on pedestal. X-66 1967–1973 12-tone tonewheel generator with frequency divider and various additional features X-77 1968–1973 A restyled H-100, designed to replace the B-3. Had its own Leslie cabinet, the X-77L
Vacuum tube musical instruments Vacuum tube musical instruments mean electronic musical instruments generating sound with vacuum tube-based electronic oscillators. Hammond Organ Company commercialized it in the late-1930s as Novachord (1939–1942) and Solovox (1940–1948). Especially, new designs introduced on Novachord — subtractive synthesis and frequency divider — were immediately followed by many manufacturers of electronic organs and polyphonic synthesizers during the 1940s-1970s. However, Hammond Organ Company did not adopt these on main products until the 1960s, except for S series chord organ (1950–1966) and "Solo Pedal Unit" on RT series and D-100 (1949–1969).
ImageModel Name / NumberYears producedDescription Novachord (model H) 1939–1942 See also site's History page. First commercial polyphonic synthesizer. Although Novachord itself is not referred to as an electronic organ, its basic design became mainstream, being implemented in electronic organs and polyphonic synthesizers during 1940s-1970s. Solovox (model J, K, L) 1940–1950 Monophonic attachment keyboard instrument, intended to accompany the pianos with lead voice of organ and orchestral sound. It consists of two units — a 3-octave mini keyboard attaching under the piano keyboard, and a tone cabinet including electronic sound generator, amplifier and loudspeaker. The sound generator is based on a vacuum tube oscillator and octave divider circuits originally designed for Novachord. There are three minor changed models: Model J (1940–1946) Model K (1946–1948) Model L (1948–1950) Solo Pedal Unit on RT series and D-100 1949–1969 Solo Pedal Unit (or Pedal Solo Unit) provides a monophonic bright bass sound on RT series and model D-100 consoles, layered with traditional polyphonic tonewheel pedal sound. Although Solo Pedal Unit is highest-note priority and it can play only one note at a time, the players can play polyphonic bass lines by the help of traditional pedal sound. The sound generator is electrically similar to Solovox Model L. It consists of a vacuum tube oscillator and five frequency divider circuits, controlled by a volume and 8-stop tablets (Bourdon 32', Bombarde 32', 16', 8', 4', 2' & 1', mute, pedal solo on) placed on the right side of lower manual. Although there are five revisions of units, these are interchangeable on all RT series consoles. S series Chord Organ 1950–1966 First chord organ. Its "easy to play" style initiated a new market segment leading to today's home keyboard market. The S series Chord Organ can be played via following interfaces: 37-note keyboard for solo or chords 96-chord buttons (12-semitones × 8-chords variation) for chords 2 wire touch-plates for strumming effect 2 bass pedals for root & 5th 1 expression pedal (or knee lever) for total volume control 3 volume knobs for volume of each part (solo, chord, bass)F-100 Extravoice(model A, B)1960-1961 / 1961-1964: Translated to English: "Introduced in 1959 and produced from June 1961, the F-100 can be seen as one of the predecessors of the later Hammond Piper. The Extravoice was one of the many inventions of the famous Hammond engineer: J.M. Hanert. ... / Two editions of this organ were produced: / Extra voice A and B. / Years built: / Model A: Jan 1960 - Sept 1961 $995 / Model B: Sept 1961- Aug 1964 $995"Descended from the Novachord and are more like a tube synthesizer than an organ, with nothing in common with the tonewheel Hammond models. They produce totally unique sounds that can be mellow and haunting or brash and quirky. They also incorporate the circuitry from a Solovox monophonic tube synthesizer, with more tonal options and greater stability than the Solovox models typically have. Used in Fiona Apple's track "Fast As You Can".See also photographs.
Transistor organs Hammond started to produce transistor organs when the production of tonewheels became too expensive, switching to full-time Integrated Circuit (IC) models in 1975. ImageModel Name / NumberYears producedDescription Aurora (Century, Custom and Classic) 1975-81 First composite spinet organ with both drawbars and electronic voices, no tonewheels.