JPS599071B2 - electronic musical instruments - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention frequency-modulates a sound source oscillator with a modulation signal having a frequency within the audible band, and utilizes sideband waves generated by this frequency modulation as overtone components of musical tones, thereby producing performances with rich timbre. This invention relates to electronic musical instruments that enable sound expression.

Synthesizer-type electronic musical instruments have been considered in which the sound source circuit is configured with a voltage-controlled variable frequency oscillator.

In the case of such electronic musical instruments, the sound source frequency can be appropriately envelope-controlled, which is effective for expressing a wide variety of performance sounds, but the waveform of the sound source signal itself is simply unified. There are few harmonic components, and the expressiveness of the tone is poor. By supplying the output signal from the variable frequency oscillator to a waveform conversion circuit and converting it into a sound source signal such as a triangular wave, square wave, or sine wave, it is possible to change the timbre expression to some extent, but even this can change the harmonics. It is not possible to sufficiently increase the wave components, and it is difficult to make the tone rich. This invention was made in view of the above points, and it is an object of the present invention to improve the performance performance by enriching the content of harmonic components in the sound source signal to obtain a performance sound with rich timbre expressiveness. The purpose of the present invention is to provide an electronic musical instrument that can be used to measure time, and includes a first variable frequency oscillator that generates a frequency signal within the audible frequency band that generates a sound source signal, and a second variable frequency oscillator that generates a frequency signal within the audible frequency band in response to key operations. 2 variable frequency oscillators, this second
The oscillation frequency of the oscillator can be adjusted and controlled, and the oscillation signal of the oscillator is supplied to an arithmetic circuit in a manner that can be selectively blocked, and the oscillation signal of the oscillator is supplied to an arithmetic circuit, and the oscillation signal of the oscillator is supplied to an arithmetic circuit, and the oscillation signal of the oscillator is selectively blocked. This calculation output is used to control the oscillation frequency of the first variable frequency oscillator, and both frequency signals of the first and second variable frequency oscillators are output as sound source signals, and both frequency signals are It is designed to be output as a sound source signal. An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows its configuration. In the keyboard circuit 11, a pitch voltage signal KV corresponding to the pitch of the operated key and a key ink signal KON corresponding to the key press and release key operations are generated in the keyboard circuit 11.
occurs. The tone high voltage signal KV from the keyboard circuit 11 is
It is supplied to a first voltage-controlled variable frequency oscillator 13 (hereinafter abbreviated as VCO) via an adder circuit 12, and this first VCO 13 oscillates a sound source signal with a frequency corresponding to the basic operation key pitch. do it like this. Further, the pitch voltage signal KV is supplied to the second CO16 via an amplifier 14 and a level adjuster 15.

This second VCO 16 generates a frequency signal within a range of ±1 octave based on the level setting of the level adjuster 15, centered on the oscillation frequency corresponding to the pitch of the operating key of the first CO 13. Then, the oscillation output signal from the second CO16 is supplied to the waveform conversion circuit 17. This waveform conversion circuit 17 converts an input signal into a signal with a sine wave, a rectangular wave, and a triangular wave, and the output signal of the sine wave is sent to the adder circuit through a level adjuster 18 such as a variable resistor. Supply to 12. This adder circuit 12 adds the pitch voltage signal KV and the sine wave signal corresponding to the oscillation signal of the second VCOl 6. Basically, the operation key pitch frequency is set in the first VCOl 3, and the waveform conversion is performed. circuit 1
A sound source signal whose frequency is modulated by a sine wave signal from 7 is oscillated. In this case, the modulation level is
It is appropriately adjusted and controlled by a level adjuster 18. That is, the first VCOl3 is basically frequency-modulated by the output frequency signal of the second COl6, and the second VCOl3 is placed on both sides of the oscillation frequency fl of the first VCOl3.
A plurality of sideband waves are generated at intervals of 6 oscillation frequencies F2.

If frequencies f1 and F2 are equal, overtone components that are exactly integral multiples of frequency f1 are formed,
When the frequencies f1 and F2 are different, harmonic components are formed that are slightly deviated from the exact integral multiple relationship of the frequency f1, and an aharmonic relationship can be realized. Furthermore, if the frequencies f1 and F2 are largely shifted using the level adjuster 15 or an octave engine (not shown) provided in the second VCO 16, the output signal of the first VCO 3 can be changed to, for example, 1. It is also possible to include non-integer overtones such as fifth overtones. The sound source signal output from the second VCO 3 is converted into a sine wave, a triangular wave, or a rectangular wave as appropriate by the waveform conversion circuit 19, and the selection switch 20 selects one waveform of the sound source signal to control the voltage. Type variable filter 21 (hereinafter referred to as V
A voltage-controlled variable gain amplifier 22 (abbreviated as VCA) controls the amplitude envelope, and the signal is led to a speaker circuit (not shown) to be emitted as a performance sound.

For the above CO13, CF21 and CA22, envelope generation circuits 23 and 24 are used, respectively.
, 25 as a control signal, and the envelope generating circuits 23 to 25 include the following:
The key ink signal KON from the keyboard circuit 11 is combined to generate an envelope waveform signal that rises and decays in response to key operations.

Waveform formation conditions such as rise, duration, and attenuation of this envelope waveform signal are set by the control circuit 26 using, for example, a variable resistance circuit. Further, the waveform conversion circuit 1
The rectangular wave and triangular wave output signals from 7 are selected by selection switch 2.
7, one of them is selected, and the V
It is supplied to CF29.

That is, the second V converted into a rectangular wave or a triangular wave
The frequency signal from the COl 6 is formed into a timbre by the VCF 29, and the musical tone signal having a different pitch from the sound source signal generated by the first VCO 3 is appropriately synthesized with the output musical tone signal from the VCA 22 and sent to a speaker circuit (not shown). This is the sound that is generated as a performance sound. That is, the VCA 22 generates a main musical tone signal that corresponds to the key operation, and this musical tone signal has the pitch pitch, timbre, and volume envelope set in accordance with the waveform shape of the envelope signal. The performance sound mode changes over time in response to the operation, and performance sounds rich in naturalness and musicality are expressed. That is, in the electronic musical instrument configured as described above, the first sound source signal constituting the main performance sound is generated from the first COl3, but this first VCOl3 is connected to the keyboard circuit. The oscillation is controlled by a signal obtained by adding a level-adjusted sine wave signal corresponding to the oscillation signal from the second VCO 16 to the pitch voltage signal KV from the second VCO 11.

Therefore, the sound source signal obtained from the first VCO13 has a fundamental frequency corresponding to the pitch voltage signal KV, and becomes a sound source signal in a state where the frequency is modulated with a period proportional to the pitch voltage signal KV, and the pitch is This generates a sound source signal containing harmonic components corresponding to the voltage signal KV, thereby expressing the effective performance sound described above. Furthermore, at the same time, the output signal from the second VCO 16 is also used as a second sound source signal, thereby making it possible to obtain performance sounds from two series sound sources. In this case, the oscillation frequency of the second VCOl 6 can be arbitrarily variably adjusted by the level adjuster 15, and therefore the overtone structure of the first sound source signal obtained from the first VCOl 3 will also change. This allows the performance sound to be more varied and natural. Here, the oscillation of the second VCO 16 is controlled by the pitch voltage signal K supplied via the level adjuster 15. Therefore, the pitch of the second sound source signal obtained from the second VCO 16 is shifted from the pitch of the operating key, and therefore, in this electronic musical instrument, the pitch is different and the harmonic structure is different. Generates two widely different sound source signals,
These are synthesized and produced as performance sounds. Furthermore, when the level adjuster 18 is set to the zero bell position,
The frequency signal from the second VCO 16 is not supplied to the adder circuit 12, and the first VCO 13 generates a normal sound source signal that is not frequency modulated.
Therefore, in this case, two
It is an electronic musical instrument that generates a series of sound source signals, and it forms performance tones with a timbre with relatively few overtone components, and it has a great effect on expanding the range of performance modes of this electronic musical instrument. . FIG. 2 shows another embodiment of the present invention, in which the first VCOl3 is connected to the pitch voltage signal K.
Controlled by the output signal from the adder circuit 12 supplied with V,
In addition, the appropriately amplified sound pitch voltage signal KV is sent to the level adjuster 1.
A second VCOl6 controlled by a signal whose level is adjusted by 5.
This is the same as in the case of FIG. 1 in that the output signal from the waveform conversion circuit 17 is supplied to the waveform conversion circuit 17.

The sine wave signal from the waveform conversion circuit 17 is
The signal is supplied to a multiplication circuit 30 composed of a VCA. This multiplier circuit 30 receives a tone high voltage signal K from the level adjuster 15.
A signal proportional to V is extracted from the 0P amplifier 31 and supplied as multiplication information, so that a voltage signal with an amplitude proportional to the pitch of the operating key is output from the multiplication circuit 30. This is because the relationship between the pitch of the output sound source signal in the first VCOl 3 and the pitch voltage signal KV is exponential, and the higher the pitch is compared to the bass, the more modulated the signal from the second VCOl 6 is. This is effective for compensating for the condition where the value becomes small. Further, the output signal from the multiplier circuit 30 is transmitted through the resistor Rl
, R2, diodes Dl, D2, and 0P amplifier 32
are supplied to an asymmetric circuit 33 consisting of resistors Rl,
The upper and lower amplitudes are made asymmetric by R2, diodes Dl, and D2.

That is, the asymmetric circuit 33 is supplied with a signal having a sinusoidal symmetrical waveform as shown by V1 in FIG.

Here, if the relationship is set to "R1>R2", a signal with an asymmetrical waveform in which the upper level is smaller than the lower level is extracted, as shown by V2 in FIG. Then, when this signal is supplied as an input signal to the (C) side terminal of the 0P amplifier constituting the adder circuit 12, the asymmetric circuit 33
The signal from 2 is inverted, resulting in an asymmetrical waveform in which the upper level is greater than the lower level, essentially as shown at V3 in FIG. Of course, the asymmetric circuit 33 may directly create an asymmetric waveform in which the upper level is larger than the lower level. That is, the first VCO
In l3, as mentioned above, the voltage signal coupled to the pitch of the output sound source signal needs to be exponential, so by using the asymmetric waveform as described above, 2nd VCO in 1 VCOl3
The state of frequency modulation by the signal from l6, that is, the state of change in pitch, is set to be vertically symmetrical.

Therefore, from the first VCO13, the tone pitch voltage signal K
A sound source signal that fluctuates vertically symmetrically with V as the center can be obtained, and the stability of the pitch can be improved. Note that the asymmetric state in the asymmetric circuit 33 can be arbitrarily set by the ratio of the values of the resistors R1 and R2.

Further, from the waveform converting circuit 19 to which the output sound source signal from the first VCO13 is combined, one of the rectangular wave and triangular wave signals is taken out via the selection switch 20, and the level is adjusted by the level adjuster 34 to convert the signal to the VCF21. If the timbre is formed by the timbre and then synthesized with the sine wave sound source signal taken out from the waveform conversion circuit 19, the musical tone can contain more harmonic components, making the performance sound richer. can be made even more effective.

In addition, the selection switch 2 selects a rectangular wave or a triangular wave signal based on the output signal of the second VCOl 6 obtained by the waveform conversion circuit 17.
8, timbre is formed by the VCF 29 to create a musical tone signal, and by composing and using the musical tone signal, an even better musical tone signal can be formed. As described above, according to the present invention, frequency modulation is applied to a sound source signal, and harmonic components can be effectively included in correspondence with the modulated signal.

Further, the modulation signal for modulating the sound source signal can be selectively blocked, and the content of overtone components in musical tones can be arbitrarily set and controlled within a sufficiently wide range. In addition, the frequency signal used for the modulation of the modulated sound source signal is also used as the sound source signal, so the electronic musical instrument obtained in this way has a very rich timbre of the performance sound. Furthermore, the state of the performance sound can be selected and set with sufficient flexibility, and the performance of the electronic musical instrument is significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram explaining an electronic musical instrument according to one embodiment of the present invention, FIG. 2 is a block diagram explaining another embodiment of the present invention, and FIG. 3 is a block diagram of the embodiment shown in FIG. It is a signal waveform diagram explaining an effect|action. 11...keyboard circuit, 12...addition circuit, 13...first variable frequency oscillator, 15,1
8, 28...Level adjuster, 16...
Second variable frequency oscillator, 17, 19... waveform conversion circuit, 21, 29... variable filter, 30
...Multiplication circuit, 33...Asymmetric circuit.

Claims (1)

[Scope of Claims] 1. A first variable frequency oscillator that generates a frequency signal within an audible band that serves as a sound source signal, a keyboard circuit that generates a pitch voltage signal corresponding to the pitch of an operating key, and a keyboard circuit that generates a pitch voltage signal corresponding to the pitch of an operating key; a second variable frequency oscillator whose oscillation frequency is controlled by the generated pitch voltage signal to generate a frequency signal within the audible band; a control means for adjusting and controlling the oscillation frequency of the second variable frequency oscillator; an arithmetic circuit that calculates a pitch voltage signal generated from the keyboard circuit and a frequency signal generated from the second variable frequency oscillator; and an output signal from the arithmetic circuit that causes the first variable frequency oscillator to oscillate. means for controlling the frequency; means for selectively blocking supply of the frequency signal generated from the second variable frequency oscillator to the arithmetic circuit; An electronic musical instrument comprising means for forming a musical tone using a frequency signal as a sound source signal. 2. The electronic musical instrument according to claim 1, wherein the arithmetic circuit is configured to perform an addition operation on the frequency signal from the second variable frequency oscillator and the pitch voltage signal. 3. The electronic musical instrument according to claim 1, wherein the blocking means comprises a variable resistor that controls the level of the frequency signal from the second variable frequency oscillator. 4. The means for performing musical tone formation includes the first and second means for forming the musical tone.
The first and second filter circuits each form a timbre of each frequency signal from the variable frequency oscillator, and the output signals of the first and second filter circuits are combined and transmitted as a musical tone signal. An electronic musical instrument according to claim 1, comprising: