DE2357167A1 - ELECTRONIC MUSICAL INSTRUMENT - Google Patents

Description

PATENT LAWYERS DR.-ING. HANS LEYH

Dipl. -Ing. Ernst Rathmann

Some"! 71st, Nov. 14, 1973 Melchioretf. 42 Uneer reference: MO90P-1044

Motorola, Inc. 9401 West Grand Avenue Franklin Park, Illinois V. St. A.

Electronic musical instrument

The invention relates to an electronic musical instrument with a Control oscillator for generating a reference frequency signal and with devices for sound signal generation and playback.

There are many known applications for which it is necessary to To create musical instruments that can be set to different tunings, these tunings of equally tuned tone sequences are different. Such musical instruments are e.g. for training

Fs / xnü purposes

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purposes to illustrate differences between modern and ancient tuned tone sequences as well as for musical experiments with non-standardized tuning systems desirable.

Several methods have been proposed to make musical ** To tune instruments on scales that are different from equally tuned tone sequences of a known type. All of these procedures need an individually adjusted, correct frequency for each tone of a scale. In order to use an instrument within the framework of these systems Tuning non-standardized tone sequences or scales has to be very complicated and time-consuming for tuning the instrument Procedures are used, in particular, experienced specialists are with appropriate equipment required, whereby tuning the instrument may take several hours and the possibility of a direct comparison of the sound quality of the different scales is excluded.

The invention is based on the object of overcoming these disadvantages and to create an electric musical instrument that varies slightly on Matched Tonieitern can be moved within a short time. In particular, it should be possible to use the instrument at the same time to be able to coordinate two differently tuned scales in order to be able to directly compare the sound quality of different, different tone sequences to be able to demonstrate. It is necessary that the individual notes of an experimental scale can be reliably reproduced, such an experimental scale is also intended to include quarter-tone sequences that are performed without the use of special equipment or the need for the use of skilled workers should be easily generated. This object is achieved according to the invention in that the device for tone signal generation comprises a programmable frequency divider with a plurality of outputs, at which a plurality of Signal frequencies with specific, a variety of complete tone

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conductors with appropriate frequency ratios among each other stands, the frequency divider having a plurality of divider chains includes variable number of pitches and the divider chains each with one Output are connected that a divider program control with the divider chains is connected to the number of pitches of the individual divider chains independent change in the frequency ratio of a signal frequency with respect to another signal frequency for determining a scale to change that an octave divider is connected to the programmable frequency divider / which supplies a plurality of octave signals, the octave divider Includes divider chains for the frequencies from the programmable frequency divider, which is divided by a whole-line multiple of two allow, and that the outputs of the octave divider are selectively connected to the playback devices via key switches.

Further features and refinements of the invention are the subject matter of further claims.

The invention is particularly advantageous in an electric musical instrument realized, which comprises a control oscillator with a crystal-controlled oscillating circuit for reasons of stability. This The control oscillator supplies a specific reference frequency signal to two circuits for generating a pair of signal frequencies. as An oscillator crystal can, for example, be a crystal tuned to 3.58 MHz Find use as it is used in the television sector. The first tone generating circuit uses twelve divider chains with selected ones Division numbers to generate twelve signals, the frequencies of which exist in a certain ratio to one another, that of the twelfth The square root of two corresponds to and thus for the generation of audio frequency signals an equally coordinated scale are suitable. A second

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Circuit for audio frequency signal generation comprises twelve divider chains, of which at least eleven are programmable. The divider chains consist of digital divider stages with a feedback that is via a switch can be connected to the respective divider stage. In this way, the number of divisions can be set to a desired value That is, the ratio of the division numbers of the various divider chains can be selected in a desired manner to create a particular pitch sequence of a musical scale. A 24-quarter tone sequence for a scale can e.g. B. be done by tuning the second circuit in such a way that frequencies are generated which between the frequencies of the first toner generating circuit lie. The tone sequences of the scales generated in the two circuits can be sent to separate Key fields are created, whereby it is possible to connect the two key fields to one another by means of a cross coupling switch in such a way that that the tones of the various tone sequences or scales can be reproduced audibly at the same time. In this way it is possible the instrument very easily and advantageously tuned to different Set scales by simply switching on the feedback paths to the individual divider stages of the divider chains. This switch-on can be controlled with the aid of program cards, jumper wires or switches on the keypad of the instrument.

The features and advantages of the invention also emerge from the following Description of an embodiment in connection with the claims and the drawing. Show it:

Fig. 1 is a block diagram of an electronic musical instrument according to the invention;

- 4 - Fig. 2

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Figure 2 is a block diagram of the divider chain within the programmable Divider according to FIG. 1, of which, however, not all parts are shown.

In Fig. 1, a control oscillator 10 is shown, which adjusts with a frequency resistor 12 is connected and is at the input of a buffer amplifier 14. The outputs of the buffer amplifier 14 are on the one hand with a fixed and on the other hand with a programmable divider 16 resp. 26-connected for sound generation. Each of these dividers has 12 outputs, which are connected to correspondingly assigned octave dividers 18 and 28, respectively. Each octave divider has 66 outputs in the present exemplary embodiment, which are connected to switches on keypads 20 and 30. The exits of the keypads 20 and 30, which can be connected to one another via a cross coupling switch 24, in order to be able to use a keypad at the same time To be able to respond to two rows of tones, 'are via an addition circuit 32 connected to an amplifier 34, the output of which with a speaker 36 is connected. A divider control program 22 is connected to the programmable divider 26.

In operation, the oscillations are transmitted from the control oscillator 10 to the buffer amplifier 14 applied, which in turn transmits the vibrations on to the dividers 16 and 26 for sound generation. The divider 16 includes twelve divider chains, the number of divisions between which is the ratio of the twelfth root of two for the generation of twelve output signals where the frequencies of the output signals are also in the ratio of the twelfth root of two to each other. The mentioned Twelve output signals define an octave of an equally tuned scale, but other numbers of divisions can also be used and thus different Division ratios are used to generate differently tuned tone sequences. Other octaves are determined by the octave divider 18 that generates the frequencies of each of the twelve applied signals

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divided by numbers with a ratio of 2: 4: 8, etc. The octave divider 18 supplies output signals whose frequencies relate to the twelve output signals from the divider 16, but in relation to these Signals are offset by one or more octaves. It should be noted that although the octave divider 18 has 66 outputs in the illustrated embodiment has any number of outputs depending on the frequency range of the instrument can be used. The 66 output signals from the octave divider 18 are applied to the keypad 20. This keypad includes 66 key switches to switch according to the pressed Keys to transmit the applied signals to the addition circuit 32. Each key switch controls a gate, which is in the form of a mechanical or electronic switch can be realized and in series with one of the 66 output lines of the octave divider 18, and this with the line to the addition circuit 32 for signal transmission connects. The cross coupling switch 24 connects corresponding key switches of the two key fields with each other, so that the tones that can be excited from the two key fields by actuating the key field switch can be energized in a keypad alone. With another Embodiment, one of the two keypads can be provided with two-pole keypad switches, each of which has one pole the associated outputs of the octave divider 18 and the other is connected to the associated outputs of the divider 28 to receive signals from to transfer both dividers at the same time. A single pole switch connected in series with one group of poles and the addition circuit 32 can be used to restore independent operations. The addition circuit 32 transfers the signals from the keypad to the Amplification to amplifier 34 and then to loudspeaker 36 for playback.

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The operation of the second divider 26 for sound generation corresponds to the operation of the first divider 16 with the exception that the division numbers of the divider 26 can be changed with the aid of the control program 22. The programmable divider stages in divider 26 are shown in FIG. 2 and are explained in more detail below. ^v

The programmable divider 26 supplies 12 output signals to another Octave divider 28. This octave divider ^ r 28 supplies 66 output signals to the Keypad 30, which is thus controlled in the same way as the keypad 20. The signals transmitted via the keypad 30 are on the addition circuit 32 applied and combined with the signals from the keypad 20, then amplified in the amplifier 34 and in the loudspeaker 36 to be reproduced. The addition circuit 32 of the amplifiers 34 and the loudspeakers 36 serve as reproducing devices for the signals via the keypads 20 and 30.

In Fig. 2 there are two divider chains 40 and 60 and a twelfth divider chain 100 corresponding to the divider chain 60 of the programmable divider 26 shown for sound generation. The first divider chain comprises eleven stages 41-51 with the division factor 2, which are also referred to as binary divisors which are connected to each other in such a way that they form a binary counter. A feedback network to adjust the divider chain at a certain count comprises a capacitor 52 which connects the output of the divider 51 to the line 53, which in turn is connected to the setting input of the divider stages 51 to 47 and 49. Although a particular feedback circuit is described as an exemplary embodiment, other feedback systems can also be used that make the desired counting sequence possible. The divider chain 60 has eleven divider stages with the division factor 2, which also are designated as binary dividers 61 to 71 and are connected as binary counters. A capacitor 72 connects the output of the divider stage

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to the feedback line 73, which is connected to the setting connections of the divider stages 61 to 71 via eleven program switches 81 to 91. The divider stages with a division factor of 2, as used in divider chains 40 and 60, are conventionally constructed from flip-flops or bistable multivibrators, such as those used in digital divider - '"* stages. These stages can be used as Although the divider chains 40 and 60 use binary divider stages which are connected as binary counters in order to carry out the division, it is also possible to use ring counters or shift registers. provided which correspond to the divider chain, so that twelve divider chains for generating the twelve * related tone frequencies can be generated.

The divider chain 40 is preprogrammed for a certain number of divisions, however, a divider chain corresponding to divider chain 60, which is programmable, could also be used. The preprogramming of the Divider chain 40 takes place by connecting the line 53 with certain different divider stages.

The number of pitches of the divider chain 60 and thus the position of the switches to 91 is determined by the frequency of the control oscillator 10 according to FIG. 1 and the musical scale to be programmed. For the For the explanation it is assumed that a Pythagorean tone sequence is to be programmed, and that the divider chain 60 is the sharp C of this tone sequence or scale generated. It should also be assumed that the frequency of the control oscillator 10 corresponds to a value which is divided by 1601 is necessary to get the output frequency at the output terminal, which is proportional to the Pythagorean sharp C.

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The divider chain 60 comprises eleven stages and the maximum count or the number of divisions is 2 or 2048 .. Therefore if all divisors are 61 to 71 are set to the binary state 0 with the division factor 2 ' are, a binary 1 appears at the output of the divider stage 71 after 2048 pulses were applied to the input of the divider stage 61. As soon as' this binary 1 occurs at the output of the divider stage 71, the division is ended by 2048. When dividing by a number less than 2048 is desired, the difference between 2048 and the The number corresponding to the desired number of divisions is preprogrammed into the divider chain 60 will. In the present exemplary embodiment, the number of division corresponds to that used for generating the Pythagorean sharp C is necessary, the value 1601, so that the number 447 in the Divider level must be programmed which is equal to the difference 2048 and 1601 is. If this number programmed 447 into the divider chain is, only 1601 pulses have to be applied to the input of the divider stage 61 until a binary 1 appears at the output of divider stage 71, i.e. division by 1601 has been carried out.

Since the divider chain comprises 60 binary divider stages, the number 447 must be in A binary form can be converted in order to be able to set the divider chain to this number. The number 447 corresponds in binary form to the Number 00110111111. This number can be pre-programmed into the divider chain 60 by closing switches 81 to 86 and switches 88 and 89 will. This means that the switches from the first to the 32nd position as well as from the 128th and 256th position of the binary number are closed. There every time a binary 1 appears at the output of the divider stage 71, this binary 1 is sent to the divider stages 61 to 66, 68 and 69 through the switch to 86 as well as 88 and 89 is created, the counting chain is then transferred to the The number 447 is preset, with which the division by the number 1601 is carried out

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is. Similarly, any number smaller than 2048 and Preset greater than 1024 on divider chain 60 by determining the binary form of the desired number and closing the appropriate switch will. The other counter chains of the divider are not shown, but they allow programming in the same way, with each Scale generated synthetically by closing the necessary switches can be done by adding the appropriate desired frequencies for each Tone of the musical scale can be generated. The technique of dividing into divider chains is known as counting up, but counting down can also be used Find use, one related to the number of divisions A standing number is programmed into the divider chain and then a count to the count Θ is carried out. There are others too Division methods applicable to achieve the desired goal.

The switches 81 to 91, which are used for programming the dividing chain 60 are necessary and, in the same way, corresponding switches of the other divider chains, not shown, in accordance with divider control program 22 according to Fig. -1. Although the switch as a single pole switch is schematic are shown, any connection between the capacitor 72 and the various divider stages is capable of programming the Counter to make. For example, secondary switches, jumper wires or electronic switching elements can be used. The instrument that preferably intended for the implementation of the invention, includes keypad switches, allowing maximum flexibility in terms of programming given is. Punch cards can also be used to set the corresponding perforated programs with jumper wires. which makes it possible to quickly reprogram the electronic instrument to specific tone sequences or scales.

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Claims

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Claims (5)

MO90P-1044 P ate η ta nsprc h e {\ J Electric musical instrument with a control oscillator for generating a reference frequency signal and with devices for generating sound signals and reproducing them, characterized in that the device for generating sound signals comprises a programmable frequency divider (26) with a plurality of outputs at which a plurality of signal frequencies with certain frequency ratios corresponding to a plurality of complete scales are available, the frequency divider comprising a plurality of divider chains (40, 60, 100) with a variable number of divisions and the divider chains are each connected to an output that a divider program control (22) with the Divider chains is connected to the division number of the individual divider chains to independently change the frequency ratio of a signal frequency with respect to another signal frequency to determine a scale that an octave divider (28) with the programmable F frequency divider is connected, which supplies a plurality of octave signals, the octave divider comprises divider chains for the frequencies from the programmable frequency divider, which allow division by an integral multiple of two, and that the outputs of the octave divider are selectively connected to the playback devices via key switches. 409821 / 09H MO90P-1044 2. Electronic musical instrument according to claim 1, characterized in that the dividing chains consist of a There are many binary divider stages that are interconnected in the form of a binary counter. 3. Electronic musical instrument according to claim 2, characterized in that the dividing chains for the changeable Frequency switching devices, with which the output of the respective chain with the input of certain • Binary divider is variably connectable in order for the divider chain to set a certain number of divisions. 4. Electronic musical instrument according to one of claims 1 to 3, characterized in that the programmable frequency divider has twelve divider chains for variably adjustable signal frequencies includes. 5. Electronic musical instrument according to one or more of claims 1 to 4, characterized in that a second frequency divider for tone generation is present, which is connected to the control oscillator and at the same time a second plurality of signal frequencies with a certain frequency ratio to one another corresponding to a complete, specific scale depending on the reference frequency signal that the second frequency divider provides a second plurality of Includes divider chains, each connected to an associated output and set to a specific number of divisions, where the division numbers are in a certain ratio to each other correspond to the frequency ratio between the audio signal frequencies of a certain scale. 409821/091 4 Empty soap