JPS5856879B2 - electronic musical instruments - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic musical instrument with improved waveform setting means for an envelope waveform signal for controlling a voltage-controlled musical tone forming circuit.

In an electronic musical instrument, a sound source signal is generated in response to a key operation, a filter circuit forms a timbre of this sound source signal, and a variable gain amplifier circuit controls an amplitude envelope to generate a musical tone signal.

In this case, in order to produce a musical tone signal rich in musicality, it is desirable to change the timbre from the start of the sound to the end, and also to arbitrarily control the amplitude envelope. It has been considered to configure a musical tone forming circuit such as a gain amplification circuit to be of a voltage control type, and to control this with an envelope waveform signal whose voltage value changes over time.

FIG. 1 shows an example of the configuration of the electronic musical instrument as described above, in which the keyboard circuit 11 generates a pitch signal KV with a voltage value corresponding to the pitch of the operated key as the key is operated, and a pitch signal KV of a voltage value corresponding to the pitch of the operated key. Generates a keying signal KON related to key operation.

The pitch signal from the keyboard circuit 11 is supplied to a VCO 12 (voltage controlled variable frequency oscillator), and this VOCl
In step 2, settings are made to oscillate a sound source signal having a frequency corresponding to the pitch of the operating key.

The sound source signal generated from VOCl 2 is transmitted to VCF 13 (
The timbre is formed by a voltage-controlled variable filter, and the VC
The amplitude envelope is set using Al 4 (voltage controlled variable gain amplifier) and the signal is extracted as a musical tone signal.The level of this musical tone signal is appropriately controlled using a tone volume 15, and the amplified signal is appropriately amplified using an amplifier 16 and then supplied to a speaker 17. Make it sound like a performance sound.

In addition, for the above VCFI 3 and VCAl 4,
Envelope waveform signals whose voltage values change over time from control waveform generators 18 and 19 are added as control signals.

For this control waveform generator 18, 19, the keyboard circuit 1
The keying signals from 1 are combined to generate an envelope waveform signal that rises when a key is pressed and attenuates when the key is released.Rising attack condition for forming this waveform A1 From this attack state to a sustained state The control circuit 20 provides a plurality of condition signals such as a decay time condition D1, a sustained sustain level condition S1, and a fall decay time condition R from the time of key release.

In CF13, the cutoff frequency is variably controlled in response to the combined envelope waveform signal, and modulation is added to the tone.
In this case, the gain is controlled so that the tone envelope is set in accordance with the envelope waveforms to be combined.

That is, the control waveform generator 18.1 from the control circuit 20
A plurality of condition signals A respectively corresponding to 9.

D, S, and H control the settings of performance sound states such as the timbre state and amplitude envelope state of the performance musical sound.

In the control circuit 20, variable resistors VRI, VH2, .
It has a voltage division setting circuit based on each variable resistor VR.
By setting 1, VH2, . . . using an external operator, the waveform state of the control envelope waveform signal, that is, the performance sound state is set and controlled.

The control circuit 20 provides basic reference cutoff frequency setting command C and command A signals to the VCF 13 through a voltage division setting circuit also using a variable resistor.

Therefore, according to such an electronic musical instrument, the control circuit 2
By manually setting each of the variable resistors VRI, VH2, . . . 0, the state of the performance sound can be set with a considerable degree of freedom.

However, in order to actually select and set one performance sound state, it is necessary to operate and set a large number of variable resistors VRI, VH2, etc. to a predetermined state, making the operation for setting the performance sound state extremely complicated. Therefore, it is difficult for beginners in particular to set the performance sound state.

This invention was made in view of the above points, and includes:
It is an object of the present invention to provide an electronic musical instrument in which a plurality of different performance sound states can be arbitrarily selected by operating a single operator, and the setting operation of the performance sound state can be easily performed, especially by beginners.

That is, in the electronic musical instrument according to the present invention, waveform forming condition signals are supplied from a plurality of nonlinear voltage conversion circuits to a control waveform generator that generates an envelope waveform signal for controlling the musical tone forming circuit. , the voltage conversion circuit is supplied with an operation setting voltage from a voltage setting circuit.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows its structure. Since the musical tone forming circuit section has the same structure as that in FIG. 1, the same reference numerals are given and the explanation thereof will be omitted.

In the control circuit 20, the control waveform generator 18
A fixed power supply +■ for the condition signal H for .degree.

This is done in consideration of the fact that when the performance sound state is set variably, the sustain level S and the falling decay time after key release do not have much effect.

Then, in order to obtain conditions A and D for the attack and decay time from the attack state, four nonlinear voltage conversion circuits 2 are used.
2a, 22b, 22c, and 22d are provided, and a voltage signal from a voltage setting circuit 23 that can variably set a voltage between +■ and 1■ is supplied to the voltage conversion circuits 222 to 22d.

In the case of the figure, the output voltage signal from the voltage conversion circuit 22a is
The output voltage signal from the voltage conversion circuit 22b is used as the condition signal Q for the CF 13 and the condition signal A for the control waveform generator 19.

Further, the output voltage signal from the voltage conversion circuit 22C is used as a condition signal to the control waveform generator 18 to the voltage conversion circuit 22C.
The output voltage signal from 2d is output from control waveform generators 18 and 1
9 as condition signals A and D, respectively.

FIG. 3 shows a specific configuration example of the nonlinear voltage conversion circuits 222 to 22d, in which the voltage signal obtained by the voltage setting circuit 23 is supplied to the operational amplifier OP1 for buffering, and the operational amplifier OP1 The output signal of transistor Tr1. It is supplied to each base circuit of Tr2.

Transistor 'rr1. The base of Tr2 is connected to diodes DI and D2 that ground the negative or positive potential directly or via a resistor, the emitter of the transistor Tr1 is grounded via a resistor, and the collector is connected to the +■ power supply. do.

Furthermore, the collector and emitter of the transistor Tr2 are connected to a power source via +■ and a resistor, and the emitter circuits of the transistors T rl + T r2 are provided with output terminals B and C, respectively.

In this case, a potential of +V is further coupled to the output terminal C via a resistor.

Therefore, if a voltage signal that changes linearly as shown in FIG. 4A is obtained from the voltage setting circuit 23 by operating the voltage setting circuit 23, the voltage signal shown in FIG. 4B is output from the output terminal B.
As shown in FIG. 4, a non-linearly varying voltage signal output as shown in FIG. 4C is obtained from the output terminal C.

Furthermore, by supplying the signals from the terminals B and C to the operational amplifier OP2, a voltage signal as shown in D in FIG. From E, an output voltage signal as shown in E in FIG. 4 can be obtained.

That is, the output voltage signals from the output terminals B, C, D, and E correspond to the output voltage signals of the nonlinear voltage conversion circuits 228 to 22d.

That is, in the electronic musical instrument configured as described above, by operating the voltage setting circuit 23 and setting the output voltage from this circuit 23, each of the voltage conversion circuits 228 to 22d is adjusted in accordance with the voltage value. The output voltage value is set independently.

Therefore, only by operating the voltage setting circuit 23, the condition signals A, D, S, H to the control waveform generators 18 and 19 can be set.
The value of and the combination thereof change, and the performance sound state of the electronic musical instrument is selectively controlled.

In this case, in order to set the combination state of the voltage signals respectively taken out from the voltage conversion circuits 222 to 22d, for example, it is necessary to experimentally create an elemental sound state similar to the performance sound state of some natural musical instruments, and What is necessary is to plot the voltage values corresponding to each condition of A, D, S, and H together with the reference cutoff frequency of the VCF 13 and Q on a graph to determine the voltage values, and each nonlinear voltage conversion circuit 222 to 22
d, a voltage signal corresponding to the above plot may be generated in response to a change in input voltage.

The non-linear voltage conversion circuits 22a to 22d are not limited to those of an analog calculation type as shown in FIG. It is effective to use a digital voltage signal from the voltage setting circuit 23 instead of an analog voltage signal.

In the above embodiment, a plurality of condition signals are collectively controlled by one voltage setting operator, but this is the fifth condition signal.
As shown in the figure, the settings may be made independently for each of A, D, S, and R.

That is, a voltage setting circuit 23a is provided for each condition such as A, D, S, and R.

23b..., and each voltage setting circuit 23a.

23b...corresponding to each nonlinear voltage conversion circuit 2.
2a1, 22a2...-22b1, 22b2- are provided.

Then, the output voltage signals from the corresponding voltage conversion circuits are distributed to the control waveform generators 18 and 19, respectively.

In this case, different voltages +Vl, +V2°...
Preset switch S1. S2. ... is provided, and this preset switch S1.82. The voltage conversion circuits 22a1 . . . ..., 22b1. If you select the voltage conversion characteristics of each of..., then A.

It is possible to diversify the selection of combinations of condition signals such as D, S, R, etc. in a sufficiently simple manner.

In this embodiment, the low frequency oscillator 2 is connected to the VCO 12.
4 is applied as a frequency modulation signal via the VCA 25 to express a vibrato effect, and the VCA 25 is controlled by a control waveform generator 26 that is controlled by the output signal of the nonlinear voltage generation circuit 22a3 By doing so, effective vibrato effect addition control can be performed.

As described above, according to the present invention, even beginners can easily select and control the envelope waveform signal that controls the musical tone forming circuit configured as a voltage-controlled type, and can select and set performance tone states with great flexibility. This makes it possible to effectively control the performance sound of an electronic musical instrument.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating a conventionally considered electronic musical instrument, FIG. 2 is a configuration diagram illustrating an electronic musical instrument according to an embodiment of the present invention, and FIG. 3 is a diagram illustrating the nonlinear voltage used in the above embodiment. FIG. 4 is a diagram showing an example of a conversion circuit, FIG. 4 is a diagram showing states of output voltages of each part of the voltage conversion circuit, and FIG. 5 is a diagram showing another embodiment of the present invention. 11...keyboard circuit, 12...voltage controlled variable frequency oscillator, 13...voltage controlled variable filter, 14...voltage controlled variable gain amplifier , 18.19... control waveform generator, 20...
...Control circuit, 22a-22d...Nonlinear voltage conversion circuit, 23...Voltage setting circuit.

Claims (1)

[Claims] 1. A musical tone forming circuit that uses a sound source signal generated in response to a key operation as a musical tone signal, a control waveform generating circuit that generates an envelope waveform signal that controls the musical tone forming state of this musical tone forming circuit, and this control waveform generating circuit. a control circuit that supplies voltage signals corresponding to each of a plurality of conditions for shaping the envelope waveform signal generated by the control circuit;
and a plurality of voltage conversion circuits that are provided corresponding to the plurality of conditions described above and each input the output voltage of the voltage setting circuit and convert it with different voltage conversion characteristics, and the output voltage of this voltage conversion circuit is An electronic musical instrument characterized in that a signal is supplied to the control waveform generation circuit as a voltage signal for setting the plurality of conditions.