JPS5840197B2 - electronic musical instruments - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic musical instrument, and more particularly to an improvement in an electronic musical instrument in which a plurality of musical tone signals each having a set pitch range are controlled by a voltage-controlled filter.

Generally, when controlling the timbre of a musical sound using a voltage-controlled filter, the energy relationship between the fundamental wave of the generated sound and its harmonic components is kept at a constant ratio regardless of the range, that is, the octave. In order to obtain a tone color, it is necessary to change the setting of the cutoff frequency of the filter according to the range of the generated musical tone.

By the way, in electronic musical instruments, in order to increase the richness of the performance sounds generated, a plurality of musical tone generation sequences are provided, and musical tone signals with different sound ranges are simultaneously extracted from each musical tone generation sequence in response to key operations. These signals are appropriately synthesized to obtain performance sounds.

In such an electronic musical instrument, when controlling the timbre of a musical tone using a voltage-controlled filter, the cutoff frequency of the filter is controlled so that the timbre remains constant regardless of the range in which the musical tone is produced. In order to achieve this, conventionally, a voltage-controlled filter was provided for each tone generation series.
Each filter controls one musical tone, that is, a sound source signal, and each filter is supplied with a control voltage signal corresponding to the sounding range of the input musical tone to individually control the setting of its cutoff frequency. I was doing it.

Therefore, a conventional electronic musical instrument with the above-mentioned configuration requires the same number of voltage-controlled filters as the number of musical tone generation sequences, which makes the configuration of the electronic musical instrument complex and expensive. It had become.

This invention has been made in view of the above-mentioned drawbacks, and its purpose is to be able to control the timbre of each musical tone in a plurality of musical tone generation sequences with a simple configuration, and also to control the timbre of each musical tone in a plurality of musical tone generation sequences, and also to control the tone color of each musical tone in a plurality of musical tone generation sequences. With this in mind, it is an object of the present invention to provide an electronic musical instrument that can prevent changes in timbre due to range switching.

For this reason, the electronic musical instrument according to the present invention includes at least two first and second musical tone generation sequences that simultaneously generate musical tone signals in predetermined ranges in response to pressed keys, and the first and second musical tone generation series. a voltage-controlled filter into which musical tone signals generated from the musical tone generation series are synthesized and input; a range setting means for switching and setting the tone range of at least the musical tone signals generated from the second musical tone generation series; a first control voltage generation circuit that generates a first control voltage signal corresponding to the range of musical tone signals generated from one musical tone generation series; and a second control voltage signal that corresponds to the range set by the range setting means. A second control voltage generation circuit that generates a signal and a selection circuit that preferentially selects and outputs one of the first and second control voltage signals are provided, and the control voltage output from the selection circuit is provided. The frequency characteristics of the voltage-controlled filter are controlled by a signal.

☆☆ Hereinafter, this invention will be explained in detail with reference to the accompanying drawings.

The figure is a block diagram showing an embodiment of an electronic musical instrument according to the present invention.

This figure shows an electronic musical instrument with a single note configuration.
The figures will be explained below according to the reference numbers.

Reference numeral 1 denotes a key switch circuit provided in the keyboard section, which sends out key data KD corresponding to key depressions.

This key data KD includes, for example, as shown in Table 1, a 2-bit code K and 1 representing the type of keyboard, and a 3-bit code B3 .
B2 and B1, and a 4-bit code N4 that represents the note name within one octave. N3. It consists of a total of 9 bits of code consisting of N2 and N1.

Reference numeral 2 denotes a frequency information storage unit into which key data KD corresponding to the pressed keys supplied from the key switch circuit 1 is inputted as an address, and outputs, for example, a frequency information value F shown in Table 2 in response to this address. It is.

In Table 2, numerical values F starting from 15 bits are shown in binary and decimal numbers, for example, from C2 to C7.

Bit 15 in a binary number represents the integer part, and bit 14
Bits 1 to 1 indicate the decimal part.

The rightmost column in Table 2 represents the binary number in the left column as 1.
This is a numerical value F expressed in decimal notation.

3 is a gate circuit controlled by a clock pulse φ.

Reference numeral 4 denotes an accumulator that accumulates the output signal of the frequency information storage section 2 supplied via the gate circuit 3, that is, the above-mentioned numerical value F.

5a and 5b are shifters for shifting the bits of the cumulative value qF, which is digital data from the accumulator 4, upward or downward in octave units by tone range specifying signals TPa and TPb from the tone range specifying circuit 14, which will be described in detail below. It is a circuit.

6a and 6b are waveform storage sections connected to shift circuits 5a and 5b, respectively, and addressed by their outputs.

These waveform storage units 6a and 6b contain amplitude data obtained by dividing a waveform such as a triangular wave, symmetrical rectangular wave, or asymmetrical rectangular wave containing many harmonics into 64 parts according to the time axis, and sampling the waveform at the divided points. Each is memorized.

Therefore, the waveform storage sections 6a and 6b are sequentially addressed by the accumulated output qF of the accumulator 4 supplied via the shift circuits 5a and 5b, respectively, and the amplitude data at the addresses are read out.

7 is a voltage-controlled variable filter to which the outputs of the waveform storage units 6a and -6b are input.

Reference numeral 8 denotes a voltage-controlled amplifier that performs envelope control on the musical tone output from the voltage-controlled filter 7.

9 generates a tone pitch voltage KV corresponding to the key data KD supplied from the key and switch circuit 1;
This is a pitch voltage generation circuit that supplies V as a control signal to the voltage-controlled variable filter 7 via the resistor 10a.

Reference numeral 11 denotes an envelope generating circuit that supplies an envelope signal ES1 to the voltage-controlled variable filter 7 via a resistor 10b.

12 is an envelope generating circuit that supplies the envelope signal ES2 to the voltage controlled amplifier 8.

13 is a sound system into which the output signal from the voltage-controlled amplifier 8, that is, a musical tone signal with an amplitude envelope is input, and the sound system is constituted by a circuit including an expression circuit, an amplifier, and a speaker. .

14 generates range designation signals TPa and TPb for designating the range of musical tone signals, that is, tone source signals, to be read from the waveform storage units 6a and 6b, and a voltage signal corresponding to either the range designation signal TPa or TPb. This is a tone generation range specifying circuit that selects and outputs the voltage signal preferentially and sends out this voltage signal as the tone range control voltage TPV.

Range designation signals TPa and T output from this circuit 14
Pb is supplied to shift circuits 5a and 5b, respectively,
Each shift circuit 5a and 5b controls the bit shift of the accumulated value qF of the accumulator 4.

Further, the TPV is supplied to the voltage-controlled variable filter 1 via a resistor 10c, and controls the cut-off frequency of the voltage-controlled variable filter 7.

The contents of the above-mentioned range designation signals TPa and TPb correspond to the range preset and the switching setting positions of the switches 15a and 15b, respectively, and the details will be described later.

First, the basic operation of the electronic musical instrument according to the present invention constructed as described above will be explained.

When a key is pressed on the keyboard of an electronic musical instrument, the key switch circuit 1 sends out key data KD corresponding to this key, and the envelope generation circuits 11 and 12 also receive data corresponding to the key pressed or released. Compatible key-on signal KON
is supplied.

This key data KD is supplied to the frequency information storage section 2, and the frequency information, that is, the numerical value F, of the storage section 2 addressed by this key data KD is read out.

This numerical value F is supplied to the accumulator 4 via the gate circuit 3, and the accumulator 4 accumulates the numerical value F at a timing speed determined by the timing signal φ input to the gate circuit 3. The calculated value qF is supplied as address information to waveform storage units 6a and 6b via shift circuits 5a and 5b.

In this case, when the accumulated value qF of the accumulator 4 reaches the final address value (for example, 64) of the waveform storage units 6a and 6b, the accumulated value qF overflows and is returned to zero, and the accumulated value qF starts accumulating from zero again.

Therefore, the period of the read waveform is determined by the accumulated value qF of the accumulator 4.

The waveform signals read out from the sequentially addressed waveform storage units 6a and 6b in this way are transferred to the mixing resistor 10a.
and 10e to the voltage-controlled variable filter 7.

The voltage-controlled variable filter 7 includes a key switch circuit 1.
An envelope signal ES is supplied from the first envelope generation circuit 11 which starts its operation in response to the key-on signal KON supplied from the controller, and this envelope signal ES,
The voltage value changes over time, and the cutoff frequency of the voltage-controlled variable filter 7 is thereby controlled to modulate the timbre.

Further, the cutoff frequency of this voltage-controlled variable filter 7 is controlled in accordance with the pitch voltage KV corresponding to the pitch of the operation key supplied from the pitch voltage generation circuit 9 via the resistor 10a. The ratio of harmonic components is made constant for each pitch to eliminate variations in timbre with respect to pitch.

The tone signal modulated in this way is further supplied to the voltage-controlled amplifier 8, where the amplitude envelope is changed by the envelope signal ES2 supplied from the second envelope generation circuit 12 which starts operating in response to the key-on signal KON. After being controlled, it is supplied to the sound system 13 and produced as a performance sound.

In the above, the accumulated value qF from the accumulator 4 is not shifted in the shift circuits 5a and 5b.
The explanation was given assuming that the tile waveforms are supplied as they are to the tiled waveform storage sections 6a and 6b, and that the sound system 13 generates musical tones of pitches corresponding to the keys pressed on the keyboard section.

Next, the configuration and operation of the tone range specifying circuit 14 will be explained in detail.

As mentioned above, the tone range designation signals TPa and TPb generated from the tone generation range designation circuit 14 are generated by shifting the bit positions of the accumulated value qF from the accumulator 4 in the shift circuits 5a and 5b, respectively. This signal is a 4-bit digital signal in this embodiment, and controls the shifting operation of the accumulated value qF in shift circuits 5a and 5b.

In addition, the range control voltage TPV includes the range designation signals TPa and T
This is to prevent the timbre from changing when the range is changed by Pb, and the range designation signal TPa
One of the preset voltage signals corresponding to and TPb is selectively outputted and supplied to the voltage-controlled variable filter 7 via the resistor 10c to control its frequency characteristics.

The sound generation range specifying circuit 14 has each musical tone generation series, that is, a first musical tone generation series composed of a shift circuit 5a and a waveform storage section 6a, and a second musical tone generation series composed of a shift circuit 5b and a waveform storage section 6b. Sound range preset switches 15a and 15b are provided corresponding to the generation series, and a signal 1 is supplied to each movable contact a of each of these preset switches 15a and 15b.

Further, each of the preset switches 15a and 15b is provided with four fixed contacts S, c, d and e, and each of the fixed contacts S, c, d and e is connected in the shift direction with respect to the shift amount in the shift circuits 5a and 5b. is specified.

For example, a fixed contact can shift 2 bits toward the upper digits (
2 feet), fixed contact C shifts 1 bit toward the upper digit (4 feet), fixed contact d shifts 1 bit toward the lower digit (8 feet) without shifting the bit), and fixed contact e shifts 1 bit toward the lower digit (16 feet). are specified respectively.

Further, output signals from fixed contacts S, c, d and e of each preset switch 15a and 15b are supplied to shift circuits 5a and 5b as 4-bit range designation signals TPa and TPb, respectively, and these signals TPa and TPb is the voltage dividing resistor 2 via the diodes 16a to 19a.
0a to 23a and to voltage dividing resistors 20b to 23b via diodes 16b to 19b, respectively.

A point A to which the voltage dividing resistors 20a to 23a are commonly connected and a point B to which the voltage dividing resistors 20b to 23b are commonly connected are commonly connected via diodes 25a and 25b.

The diodes 25a and 25b constitute a voltage selection circuit 25, which has the function of selecting either the voltage at point A or point B.

The range control voltage TPV of the voltage selection circuit 25 is supplied to the voltage controlled filter 7 via the resistor 10c.

In this case, when the voltage-controlled filter 7 has low-pass characteristics, the anodes of the diodes 25a and 25b are connected to points A and B, respectively, as shown in the figure.
As a result, the voltage selection circuit 25 is configured to output a voltage signal having a higher voltage value of either the voltage at the point A or the voltage at the point B.

If the voltage-controlled variable filter 7 has a no-pass characteristic, the cathodes of the diodes 25a and 25b are connected to the point A and the point B, respectively, contrary to the illustration. The voltage selection circuit 25 is configured to output a voltage signal having a lower voltage value of either one of the voltages at point B.

Therefore, the range control voltage TP which is the output of the voltage selection circuit 25
V corresponds to the characteristics of the voltage control filter 7, and the voltage dividing point A
The voltage at either point or point B is selectively output, that is, it is selectively output preferentially.

Moreover, the voltage-controlled variable filter 7 has a control voltage (pitch voltage KV, range control voltage TPV, and envelope signal ES1) regardless of whether it has a low-pass characteristic or a bypass characteristic.
) becomes higher, the cutoff frequency also becomes higher.

In the following description, the voltage-controlled variable filter 7 will be described as having a low-pass characteristic.

In the sound range designation circuit 14 configured in this way,
The range preset switches 15a and 15b are in the illustrated state, that is, the movable contact a of the preset switch 15a is the fixed contact d, and the movable contact a of the preset switch 15b is
will explain the state in which they are respectively connected to the fixed contact C.

Fixed contacts in the preset switch 15a, c,
d and e are connected so that only the fixed contact d outputs the signal 11 through the movable contact a, so the contacts s, c, d, and e are ゝ0〃, ゝ0〃, ゝ1 and 10 are output respectively.

That is, the range designation signal TPa is '0010'' (8 feet).

On the other hand, there is a fixed contact in the reset switch 15b.

For c, d, and e, since only the fixed contact C outputs the signal "1", the range designation signal TPb becomes +ioo (4 feet).

The shift circuits 5a and 5b here are 8fee)'001
The range designation signal TP is set to perform a shift operation based on 0// and is input to the shift circuit 5a.
Since a is '0010//, no shift operation is performed in this case, and the input cumulative value qF is directly supplied to the waveform storage section 6a as an address input.

Also, in the shift circuit 5b, the input range designation signal TPb
is '01.00〃, the input cumulative value qF
is shifted by 1 bit toward the upper digit and stored in the waveform storage section 6b.
as address input.

As a result, the waveform storage section 6a outputs a musical tone signal having a standard range of 8 feet, that is, a musical tone signal at a pitch corresponding to each key of the keyboard section.

On the other hand, the waveform storage section 6b outputs a musical tone signal that has been foot-changed to 4 feet, which is a range one octave higher than 8 feet.

Furthermore, when the movable contact a of the preset switch 15a is switched to the fixed contact, the range designation signal TPa becomes '100'.
0'', the accumulated value qF is shifted by 2 bits in the direction of the higher digits, and a musical tone signal foot-changed to 2 feet is output from the waveform storage section 6a.

As is clear from the above, when the movable contact a of the preset switch 15a is switched to the fixed contact C, the musical tone signal output from the waveform storage section 6a is foot-changed to 4 feet, one octave higher, and Fixed contact e
If you switch to ■, the feet will be changed to 16 feet, an octave lower.

Since the explanation for the preset switch 15b is similar to that in the above case, the explanation thereof will be omitted.

In this manner, by appropriately setting the range precent switches 15a and 15b, the ranges of the musical tone signals output from the waveform storage units 6a and 6b can be independently and arbitrarily controlled.

According to the range specification (feet change), the voltage signal preset to the resistors 20a to 23a and 20b to 23b for the range specification signals TPa and TPb is applied to the voltage division point A.
and B.

In the voltage selection circuit 25, one of the voltage signals generated at the voltage division points A and B is selectively outputted, and one of the voltage signals having a higher voltage value is output as the range control voltage TPV via the resistor 10c. It is supplied to filter 7.

As a result, a range designation signal TP that specifies a high sounding range
The cutoff frequency of the filter 7 is set in accordance with the amount of foot change due to a or TPb.

In this case, since the voltage-controlled variable filter 7 is supplied with two musical tone signals with different tonal ranges, the tone-range control voltage TPV applied to the voltage-controlled filter 7 is applied to the tonal range of either of the two musical tone signals. It is necessary to use a representative voltage signal.

The representative one is determined by the characteristics of the voltage-controlled variable filter 7. In this embodiment, since the voltage-controlled variable filter 7 has low-pass characteristics as described above, the voltage-controlled variable filter 7 A voltage signal corresponding to a high range (feet) of the input musical tone signals is selected by a voltage selection circuit 25 and is used as a range control voltage TPV.

If a voltage signal corresponding to a lower range of musical tone signals is used as the range control voltage TPV, the cutoff frequency of the voltage-controlled variable filter 7 will shift to a lower range, and musical tone signals in higher ranges will be subject to voltage control. Type variable filter 7
In the worst case, the musical tone signal in the high range will be cut by the voltage-controlled variable filter 7, and since the voltage-controlled variable filter 7 has a low-pass characteristic, the tone will change greatly. There will be a situation where something disappears.

In this sense, the voltage selection circuit 25 of the sounding range designation circuit 14 is an important component in this electronic musical instrument, and thereby prevents the inconvenience when a plurality of different musical tone signals are applied to one voltage-controlled filter I. .

The above description has been made on the case where the voltage-controlled variable filter 7 has a bypass characteristic, but if it has a low-pass characteristic, the voltage selection circuit 25 can of course be configured to selectively output a voltage signal corresponding to a low frequency range. It is.

In the embodiment of the present invention, there are two musical tone generation sequences, and the tone generation range of each musical tone can be independently switched and set, but it is possible to easily increase the number of musical tone generation sequences. In addition, it is not necessary to configure each series to be able to switch the sound range, and in a certain series, the sound range may be fixed to the standard range (8 feet) from the beginning.

Further, as an embodiment of the present invention, a single-tone electronic musical instrument has been described, but the present invention is not limited to this, but can also be applied to a multi-tone electronic musical instrument that has multiple sounding channels that can simultaneously produce sounds. It is possible.

As described in detail above, according to the present invention, it is possible to simultaneously control multiple tones in different ranges with one voltage-controlled filter, so the configuration of an electronic musical instrument can be simplified. The price can also be reduced.

In addition, the range control voltage based on the range designation control of the generated musical sound is supplied to a voltage-controlled variable filter, which controls the frequency characteristics of the filter, thereby preventing changes in tone due to changes in the sound range designation. It also has excellent effects such as being able to produce ensemble effects in any range of sounds.

[Brief explanation of the drawing]

The figure is a block diagram showing an embodiment of an electronic musical instrument according to the present invention. 1...key, switch m path, 2. ...080 frequency information storage section, 3... gate circuit, 4...
...Accumulator, 5a, sb...Shift circuit, 6a, 6b...Waveform storage unit, 7.
...Voltage controlled variable filter, 8...°°゛Voltage controlled amplifier, 9...Tone pitch voltage generation circuit, l
L12... Envelope generation circuit, 14...
...Sound range specification circuit, 15a, 15b...
...Sound range preset switch, 25...Voltage selection circuit.

Claims (1)

[Scope of Claims] 1. At least two musical tone generation series (2) and a second musical tone generation series that simultaneously generate musical tone signals in predetermined ranges corresponding to the suppressed keys; and the first and second musical tone generation series. a voltage-controlled filter into which musical tone signals generated from the musical tone signals are synthesized and inputted; a range setting means for switching and setting the tone range of the musical tone signals generated from at least the second musical tone generation series; and the first musical tone. a first control voltage generation circuit that generates a first control voltage signal corresponding to the tone range setting of the musical tone signal generated from the generation sequence;
a second control voltage generation circuit that generates a control voltage signal; and a selection circuit that preferentially selects and outputs one of the first and second control voltage signals, the control voltage signal being output from the selection circuit. An electronic musical instrument characterized in that the frequency characteristics of the voltage-controlled filter are controlled by a control voltage signal.