US3636231A - Dc keyed synthesis organ employing an integrated circuit - Google Patents

Dc keyed synthesis organ employing an integrated circuit Download PDF

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Publication number
US3636231A
US3636231A US135050A US3636231DA US3636231A US 3636231 A US3636231 A US 3636231A US 135050 A US135050 A US 135050A US 3636231D A US3636231D A US 3636231DA US 3636231 A US3636231 A US 3636231A
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United States
Prior art keywords
keying
signals
transistors
individually
harmonics
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Expired - Lifetime
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US135050A
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English (en)
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Ray B Schrecongost
David Millet
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Marmon Co
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Hammond Corp
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    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10H—ELECTROPHONIC MUSICAL INSTRUMENTS; INSTRUMENTS IN WHICH THE TONES ARE GENERATED BY ELECTROMECHANICAL MEANS OR ELECTRONIC GENERATORS, OR IN WHICH THE TONES ARE SYNTHESISED FROM A DATA STORE
    • G10H1/00—Details of electrophonic musical instruments
    • G10H1/02—Means for controlling the tone frequencies, e.g. attack or decay; Means for producing special musical effects, e.g. vibratos or glissandos
    • G10H1/06—Circuits for establishing the harmonic content of tones, or other arrangements for changing the tone colour
    • G10H1/08—Circuits for establishing the harmonic content of tones, or other arrangements for changing the tone colour by combining tones
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S84/00—Music
    • Y10S84/08—Keyed oscillators

Definitions

  • a DC voltage is scaled to several [5 u in CI G1 0h 6 appropriate selected levels for the fundamental and individual [58] Field 19 1 22 harmonics and chopped by tone signals for the fundamental 24 5 and selected harmonics to provide a collection of appropriate- 1y scaled square wave signals at the chopping frequencies. These square waves are individually keyed with appropriate [56] Reterences Cited envelope control through band pass sine filters adapted to re- UNITED STATES PATENTS ject all but the fundamentals of the keyed signals.
  • the filtered outputs are mixed to supply output musical signals of ap 1,956,350 4/1934 Hammond ..84/1.23 X i m ha onic quality having a desirable attack and 2,478,973 8/1949 Mahren ....84/1.23 X decay enve1ope 2,498,337 2/1950 Kent ..84/1.22 3,410,948 1 1/1968 lshibashi et a1.
  • a synthesis organ is based upon the knowledge that sustained complex musical tones can be synthesized by mixing properly scaled sine waves having frequencies representative of the fundamental and the various harmonics of the tone to be synthesized. Customarily this is done by having each organ playing key operate a group of contacts, such that when, for instance, the playing key for A-440 Hz. is pressed, it connects a sine wave generator operating at 440 Hz. to a fundamental bus, the 88 -Hz. generator to a second harmonic bus, the 1,320-Hz. generator to a third harmonic bus and so on. By connecting the various buses to the output through voltage divider resistor or transformer primary taps, the relative strengths of the various harmonics can be adjusted as desired. Usually nine or so contacts for each of most of the playing keys are necessary in such organs.
  • the system has distinct advantages in that great control of tone quality is possible since the fundamental and each harmonic has its level independently selected as desired.
  • a formant or bright wave organ uses bright wave signals having a high order of harmonic content as the starting point.
  • Formant circuits which resonate or otherwise discriminate on a frequency basis are then used to alter the harmonic balance of these complex signals.
  • This system does not have the choice of tone coloration available with the synthesis approach, but since it is not necessary to key a multiplicity of signals representative of the fundamental and various harmonics separately, it is feasible to provide direct current (DC) keying to give more elaborate tone envelopes. This, in general, is because only one DC keyer is necessary per tone signal source to key the complex signals.
  • the present invention provides a system for DC keying the fundamental and various harmonics individually with full choice of the relative levels of the various harmonics and otherwise provides the advantages of single contact DC keying in an organ of the synthesis type.
  • the system also makes use of square-wave signals which are less expensive to provide than sine waves.
  • a relatively inexpensive arrangement for providing signals for all of the musical tones necessary in an organ is to provide for the 12 tones of the top octave of the instrument and then to use bistable flip-flop frequency dividers, which divide by two, to provide the signals for the next lower octave and another set of dividers to obtain the next lower octave, and so on. Since the output signals from the most commonly used binary dividers are in the form of square waves, these signals cannot be used directly in a synthesis organ which fundamentally depends upon a selected mixture of sine waves. This invention makes use of such square-wave signals without the previously proposed expedient of providing sine wave filters individual to each of the outputs.
  • FIG. 1 of the drawing is a circuit diagram illustrating the invention.
  • FIG. 2 illustrates a minor modification which may optionally be substituted for a portion of the circuit of FIG. 1.
  • a single keying block is I indicated at 10 and is so organized as to provide the keying functions for all of the signals which may be called upon to supply tones for a particular organ playing key.
  • the particular block shown is for the A-playing key having its fundamental frequency at the international standard 440 Hz. Only one keying block is shown since the others for other playing keys may be identical, but with different connections as will appear presently.
  • the individual signals are connected to leads 20, 22, 24, 26, 28, 30, 32, 34 and 36. These are respectively for the 8 or fundamental at 440 1-12., the 4 or second harmonic at 880 Hz., the 2% or third harmonic at 1,320 Hz., the 2 at 1,760 Hz., the 1 3/5' at 220 Hz., the 1% at 2,640 Hz., the l at 3,520 Hz., the 16' or subfundamental at 220 Hz., and the 5% or subthird at 660 Hz.
  • These signals may all be assumed to supply square waves having fundamentals at the frequencies designated accompanied by a declining series of odd harmonics as is characteristic of square waves. These signals will also supply where appropriate the inputs to other keyer blocks for other playing keys. For example, the 440-Hz. signal supplies the fundamental tone to the block shown. It also supplies the second harmonic for the A-key an octave lower, the fourth harmonic for the A-key two octaves lower and so on. This general arrangement of multiple use of signals is well understood practice in synthesis organs and so additional discussion is not necessary.
  • Anyone not familiar with the basic system is referred to the previously mentioned U.S. patent to Hammond which discusses the scheme in detail.
  • the keying block 10 is of the MOSFET integrated circuit type with all of the active elements formed upon a single piece of substrate material or chip. Other circuit elements may of course occupy other portions of the chip, but such other elements form no part of this invention. So far as this invention is concerned, the chip has nine identical sections labeled from the left SF, S3, F, 2, 3, 4, 5, 6 and 8, referring in order to the keying section for the previously mentioned subfundamental, subthird, fundamental, second harmonic, third harmonic, fourth harmonic, fifth harmonic, sixth harmonic and eighth harmonic.
  • the nine keyer sections are each made up of two MOSFET (Metal Oxide Silicon Field Effect Transistor) elements. These transistors, as those familiar with this art will known have the characteristic that conduction between the drain, or input, and the source, or output, depends upon the potential at the gate; the more negative the gate beyond the threshold level, the greater the conduction, for a P"-type enhancement MOSFE'I.
  • MOSFET Metal Oxide Silicon Field Effect Transistor
  • a -5-v. terminal is indicated at 40.
  • This terminal is connected to one end of a low impedance tapped resistor 42, connected to ground at its other end. Any voltage in previously determined discreet steps between -5 v. and ground is, therefore, available at the various taps.
  • the taps are connected in order to eight parallel contact strips 44, 46, 48, 50, 52, 54, 56 and 58 so that these strips are at scaled potentials between 5 v. at strip 44 and ground at strip 58.
  • Nine slides or drawbars, indicated at 60 and labeled individually for consistency with the same position designations used to indicate the keyers they control, are arranged to be moved across these contact strips.
  • slide 60 at position SF can be drawn upwardly from the position shown such that its contact member 62 can engage any one of the contact strips 44 to 58 so as to select the desired potential between 5 v. and ground to be applied to the lead 64 connected to the slides contact member 62.
  • Leads for the slide contact members 62 are shown in the following table.
  • the previously mentioned DC lead 64 is connected to the drain of input transistor 82 and the gate to signal lead 34 which carries the square wave 16 signal at a frequency of 220 Hz.
  • the source is connected by lead 86 to the drain of output transistor 84, the source of which is connected to an output lead 88 for the keyed 16' square-wave signal.
  • the gate of transistor 84 is connected to keying lead 90 which is common to the gates of all of the output transistors for the other keyer sections in the block.
  • a supply of DC keying potential at 25 v. is indicated at 92 and this supply is connected to keying lead 90 through normally open contacts which are an element of the organ playing key 94 for the A-key having its fundamental at 440 Hz. When the playing key is pressed, these contacts close and when the key is released, they separate.
  • each input transistor 82 is connected to its appropriate DC lead 64-80 so that the DC level at each drain can be as selected by the appropriate slide 60.
  • the gates of the input transistors 82 are connected to the appropriate square-wave signals 20 to 36. These squarewave signals have a negative voltage swing sufiicient to fully drive the input transistors 82 in the present application.
  • the source of input transistor 82 is connected to the drain of output transistor 84. All gates of the output transistors 84 are connected to lead 90, and the output sources are connected individually to the appropriate square-wave output leads 88.
  • the system operates as follows.
  • Setting of the individual slides 60 determines individually the DC potentials supplied to the drains of the input transistors of the keyers for the individual harmonic signals.
  • the DC at the drains appears or not at the sources of transistors 82 at the frequency of the input signal at the gates. This is because the abrupt negative swings of the square-wave signals open and closeconduction through the FET abruptly at the signal frequency.
  • any DC potential is selected at appropriate slide 60 and applied to the drain of input transistor 82 of keyer section SF, the output at the source of this transistor will be a square-wave signal at 220 Hz. at a level which is a function of the selected voltage.
  • the various square-wave signals at the potentials selected by the slides 60 and at the frequencies of the various signals appear at the sources of the output transistors 82. These transistors are normally turned off until the playing key for the whole block 10 is pressed. When this happens, the potential on lead drops toward 25 v. at a rate determined principally by the values of resistor 96 and capacitor 98 and thus, conduction through all of the output FETs is established smoothly and simultaneously. Conversely, when the playing key is released, the output FETs are smoothly and simultaneously turned off at a rate determined largely by the values of capacitor 98 and resistor 100.
  • the output (source at 84) is terminated in a low impedance, and the impedance of 82 is much lower than 84, and thus an envelope of current is produced, which is proportional to the voltage on lead 90 and the voltage on lead 64-80.
  • the leads 88 are connected to sine filters at 102 and the outputs of the filter section are collected in common lead 104 which is connected in turn to the output section 106 of the organ which for the purpose of this invention may be assumed to be conventional.
  • the sine filters at 102 are preferably of the band pass type such that one filter will pass six to 13 or so adjacent semitones. Up to 18 is possible, but usually less total expense for the system will be involved if the bands are held to about an octave. Filters of this type remove from the input square-wave signals all but the fundamental so that the outputs collected at 104 are substantially sine waves. This is not difficult of accomplishment with filters of considerable bandwidth since the closest harmonic to the fundamental in a square wave is at three times the fundamental frequency. These sine filters, therefore, need not be provided for each musical signal source, but as suggested above, each filter section can conveniently serve six to 13 or so adjacent semitones. Additional filter input leads shown collectively at 108 are for connection to other keyer blocks, not shown, but which are connected so as to use the same group of sine filters.
  • the system provides for the synthesis of sine waves representative of the fundamental and appropriate harmonics with each of the harmonics scaled as desired relative to the others by appropriate settings of the slides or drawbars 60.
  • DC keying is provided for the fundamental and all of the harmonics with all of the advantages normally associated with DC keying, such, for instance, as avoidance of transients, adaptability to wide range control over the keying envelope, single contact keying of DC voltages at a level more appropriate to make and break contacts than is usually possible to achieve with AC signals.
  • FIG. 2 A minor modification of the system is shown in FIG. 2.
  • the keying lead 90 and the signal lead 34 are reversed.
  • the effect of this is to apply the keying envelope to the drawbar voltage as selected by the slides 60 at the input transistor and subsequently to chop the DC envelope at the appropriate frequency in the second or output transistor. Which of these arrangements is used in practice is largely a matter of choice and convenience.
  • harmonics includes the fundamental or unison harmonic where referring to the frequencies which are elements of the synthesis.
  • the keying system called for in claim 1 including means for applying an attack and decay envelope to the keying potential when said playing key contacts are actuated.
  • the keying system called for in claim 2 including means for applying an attack and decay envelope to the keying potential when said playing key contacts are actuated.
  • the keying system called for in claim 3 including means for applying an attack and decay envelope to the keying potential when said playing key contacts are actuated.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
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US135050A 1971-04-19 1971-04-19 Dc keyed synthesis organ employing an integrated circuit Expired - Lifetime US3636231A (en)

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US13505071A 1971-04-19 1971-04-19

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US (1) US3636231A (enrdf_load_stackoverflow)
JP (1) JPS5124884B1 (enrdf_load_stackoverflow)
BR (1) BR7202363D0 (enrdf_load_stackoverflow)
CA (1) CA930575A (enrdf_load_stackoverflow)
DE (1) DE2219559C2 (enrdf_load_stackoverflow)
GB (1) GB1335953A (enrdf_load_stackoverflow)
IT (1) IT951339B (enrdf_load_stackoverflow)
NL (1) NL7205165A (enrdf_load_stackoverflow)

Cited By (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3748944A (en) * 1971-09-29 1973-07-31 Hammond Corp Integrated circuit synthesis and bright wave organ system
US3755609A (en) * 1972-04-28 1973-08-28 Hammond Corp Integrated circuit all-harmonic wave organ system including provision for flute tones and pedal notes
US3764721A (en) * 1971-09-30 1973-10-09 Motorola Inc Electronic musical instrument
US3842183A (en) * 1972-11-30 1974-10-15 Nippon Musical Instruments Mfg Electronic musical instrument provided with devices for indicating preset state of respective voices
US3854365A (en) * 1971-07-31 1974-12-17 Nippon Musical Instruments Mfg Electronic musical instruments reading memorized waveforms for tone generation and tone control
US3878749A (en) * 1972-12-12 1975-04-22 Allen Organ Co Walsh function tone generator and system
US3935783A (en) * 1974-07-08 1976-02-03 The Wurlitzer Company Electronic piano circuit
US3939750A (en) * 1974-03-06 1976-02-24 Matsushita Electric Industrial Co., Ltd. Electronic organ
US3986426A (en) * 1975-08-28 1976-10-19 Mark Edwin Faulhaber Music synthesizer
US3999457A (en) * 1972-03-17 1976-12-28 Adolf Michel Key system for controlling the rate of attack in electronic musical instruments
US4024786A (en) * 1974-06-03 1977-05-24 The Wurlitzer Company Electronic musical instrument using integrated circuit components
US4038896A (en) * 1975-09-05 1977-08-02 Faulkner Alfred H Electronic organ with multi-pitch note generators
US4083285A (en) * 1974-09-27 1978-04-11 Nippon Gakki Seizo Kabushiki Kaisha Electronic musical instrument
EP0006731A1 (en) * 1978-06-20 1980-01-09 The Wurlitzer Company Large scale integrated circuit chip for an electronic organ
FR2436460A1 (fr) * 1978-09-15 1980-04-11 Casio Computer Co Ltd Instrument de musique electronique
US4226157A (en) * 1978-06-20 1980-10-07 The Wurlitzer Company Waveform synthesis for an electronic musical instrument
US4236435A (en) * 1977-05-16 1980-12-02 Victor Company Of Japan, Limited Keying system in an electronic musical instrument
US4236436A (en) * 1978-11-08 1980-12-02 Kimball International, Inc. Electronic music synthesizer
US4245542A (en) * 1978-11-27 1981-01-20 Allen Organ Company Method and apparatus for timbre control in an electronic musical instrument
US4278001A (en) * 1979-12-26 1981-07-14 Marmon Company Selective keyer biasing to enhance percussion effect
US4282791A (en) * 1979-12-26 1981-08-11 Marmon Company Keyer system for an electronic organ
US4296666A (en) * 1978-11-20 1981-10-27 Kimball International, Inc. Solo sustain keyer system
US4297935A (en) * 1978-02-24 1981-11-03 Marmon Company Divider keyer circuit for synthesis organ
US4319508A (en) * 1978-06-20 1982-03-16 The Wurlitzer Company Modular, expandable digital organ system
US4319511A (en) * 1977-11-05 1982-03-16 Kabushiki Kaisha Kawai Gakki Seisakusho Tone source for an electronic musical instrument
US4364296A (en) * 1980-02-21 1982-12-21 Reinhard Franz Electrical musical instrument
US4409877A (en) * 1979-06-11 1983-10-18 Cbs, Inc. Electronic tone generating system
US4475430A (en) * 1983-06-17 1984-10-09 The Marmon Group, Inc. Differential sampling circuit for improving signal to noise ratio in an electronic organ having multiplexed keying
US4922246A (en) * 1986-11-25 1990-05-01 Massachusetts Institute Of Technology Message merging device

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2738359C3 (de) * 1977-08-25 1981-08-13 Haus-Musikelektronik oHG, 8752 Schöllkrippen Speicherprogrammierbares Zugriegelwerk für eine elektronische Orgel

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1956350A (en) * 1934-01-19 1934-04-24 Hammond Laurens Electrical musical instrument
US2478973A (en) * 1948-04-05 1949-08-16 Ct Res Lab Inc Variable wave generator
US2498337A (en) * 1945-04-20 1950-02-21 Conn Ltd C G Electrical musical instrument
US3410948A (en) * 1963-09-30 1968-11-12 Victor Company Of Japan Spectrum adding system for electronic musical instruments
US3417189A (en) * 1965-03-29 1968-12-17 Baldwin Co D H Keying system for electronic musical percussion simulator
US3505461A (en) * 1965-12-20 1970-04-07 Matsushita Electric Ind Co Ltd Electronic musical instrument for producing novel acoustic effects from multitone signals
US3534144A (en) * 1969-01-02 1970-10-13 Hammond Corp Keyer-synthesizer for an electronic musical instrument employing an integrated circuit

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1956350A (en) * 1934-01-19 1934-04-24 Hammond Laurens Electrical musical instrument
US2498337A (en) * 1945-04-20 1950-02-21 Conn Ltd C G Electrical musical instrument
US2478973A (en) * 1948-04-05 1949-08-16 Ct Res Lab Inc Variable wave generator
US3410948A (en) * 1963-09-30 1968-11-12 Victor Company Of Japan Spectrum adding system for electronic musical instruments
US3417189A (en) * 1965-03-29 1968-12-17 Baldwin Co D H Keying system for electronic musical percussion simulator
US3505461A (en) * 1965-12-20 1970-04-07 Matsushita Electric Ind Co Ltd Electronic musical instrument for producing novel acoustic effects from multitone signals
US3534144A (en) * 1969-01-02 1970-10-13 Hammond Corp Keyer-synthesizer for an electronic musical instrument employing an integrated circuit

Cited By (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3854365A (en) * 1971-07-31 1974-12-17 Nippon Musical Instruments Mfg Electronic musical instruments reading memorized waveforms for tone generation and tone control
US3748944A (en) * 1971-09-29 1973-07-31 Hammond Corp Integrated circuit synthesis and bright wave organ system
US3764721A (en) * 1971-09-30 1973-10-09 Motorola Inc Electronic musical instrument
US3999457A (en) * 1972-03-17 1976-12-28 Adolf Michel Key system for controlling the rate of attack in electronic musical instruments
US3755609A (en) * 1972-04-28 1973-08-28 Hammond Corp Integrated circuit all-harmonic wave organ system including provision for flute tones and pedal notes
US3842183A (en) * 1972-11-30 1974-10-15 Nippon Musical Instruments Mfg Electronic musical instrument provided with devices for indicating preset state of respective voices
US3878749A (en) * 1972-12-12 1975-04-22 Allen Organ Co Walsh function tone generator and system
US3939750A (en) * 1974-03-06 1976-02-24 Matsushita Electric Industrial Co., Ltd. Electronic organ
US4024786A (en) * 1974-06-03 1977-05-24 The Wurlitzer Company Electronic musical instrument using integrated circuit components
US3935783A (en) * 1974-07-08 1976-02-03 The Wurlitzer Company Electronic piano circuit
US4083285A (en) * 1974-09-27 1978-04-11 Nippon Gakki Seizo Kabushiki Kaisha Electronic musical instrument
US3986426A (en) * 1975-08-28 1976-10-19 Mark Edwin Faulhaber Music synthesizer
US4070943A (en) * 1975-09-05 1978-01-31 Faulkner Alfred H Electronic organ keying system
US4038896A (en) * 1975-09-05 1977-08-02 Faulkner Alfred H Electronic organ with multi-pitch note generators
US4236435A (en) * 1977-05-16 1980-12-02 Victor Company Of Japan, Limited Keying system in an electronic musical instrument
US4319511A (en) * 1977-11-05 1982-03-16 Kabushiki Kaisha Kawai Gakki Seisakusho Tone source for an electronic musical instrument
US4297935A (en) * 1978-02-24 1981-11-03 Marmon Company Divider keyer circuit for synthesis organ
EP0006731A1 (en) * 1978-06-20 1980-01-09 The Wurlitzer Company Large scale integrated circuit chip for an electronic organ
US4226157A (en) * 1978-06-20 1980-10-07 The Wurlitzer Company Waveform synthesis for an electronic musical instrument
US4319508A (en) * 1978-06-20 1982-03-16 The Wurlitzer Company Modular, expandable digital organ system
US4419919A (en) * 1978-09-14 1983-12-13 Casio Computer Co., Ltd. Electronic musical instrument
FR2436460A1 (fr) * 1978-09-15 1980-04-11 Casio Computer Co Ltd Instrument de musique electronique
US4236436A (en) * 1978-11-08 1980-12-02 Kimball International, Inc. Electronic music synthesizer
US4296666A (en) * 1978-11-20 1981-10-27 Kimball International, Inc. Solo sustain keyer system
US4245542A (en) * 1978-11-27 1981-01-20 Allen Organ Company Method and apparatus for timbre control in an electronic musical instrument
US4409877A (en) * 1979-06-11 1983-10-18 Cbs, Inc. Electronic tone generating system
US4282791A (en) * 1979-12-26 1981-08-11 Marmon Company Keyer system for an electronic organ
US4278001A (en) * 1979-12-26 1981-07-14 Marmon Company Selective keyer biasing to enhance percussion effect
US4364296A (en) * 1980-02-21 1982-12-21 Reinhard Franz Electrical musical instrument
US4475430A (en) * 1983-06-17 1984-10-09 The Marmon Group, Inc. Differential sampling circuit for improving signal to noise ratio in an electronic organ having multiplexed keying
US4922246A (en) * 1986-11-25 1990-05-01 Massachusetts Institute Of Technology Message merging device

Also Published As

Publication number Publication date
JPS5124884B1 (enrdf_load_stackoverflow) 1976-07-27
NL7205165A (enrdf_load_stackoverflow) 1972-10-23
CA930575A (en) 1973-07-24
BR7202363D0 (pt) 1973-06-14
DE2219559A1 (de) 1972-11-02
DE2219559C2 (de) 1981-10-15
GB1335953A (en) 1973-10-31
IT951339B (it) 1973-06-30

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