JPS5913757B2 - Electronic musical instrument sound source device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an electronic musical instrument that uses an anti-logarithmic amplifier using a semiconductor PN junction as an anti-logarithmic conversion element to convert a pitch control voltage of an arithmetic level to a corresponding geometric pitch. Regarding the sound source device, in particular, the temperature sensitive resistor for temperature compensation which is indispensable to the inverse logarithmic amplifier is completely unnecessary.

A VCO (voltage controlled oscillator) is used in the sound source of conventional electronic musical instruments, especially musical synthesizers, to obtain a scale frequency corresponding to a pressed key.

That is, a method is often used in which a VCO is controlled using a geometric voltage obtained by converting an arithmetic voltage corresponding to each key using an inverse logarithmic amplifier to obtain a scale frequency corresponding to the pitch of each key. Moreover, the anti-logarithmic amplifier uses transistors, diodes, etc.
In most cases, N-junctions are used as antilogarithmic transformation elements. The voltage V-current characteristic of a PN junction of a semiconductor is expressed as follows.

Here, Is is the reverse saturation current, k is the Boltzmann constant, T is the Gelpin temperature, and q is the amount of electron charge. That is, P.N.
Although the junction has an anti-logarithmic conversion element, it also has a change element due to temperature T. In particular, although the inverse saturation current 1s is small in absolute value, it changes almost exponentially with temperature changes, so when configuring an inverse logarithmic amplifier, it is necessary to One of the PN junctions of is used for voltage-current inverse logarithm conversion,
The other is used to cancel the reverse saturation current 1s, and the reverse saturation current 1
This is to eliminate fluctuations in the anti-logarithmic conversion characteristics due to temperature changes in s. However, since the temperature T in the above characteristic equation is in the exponential term, pairability cannot be compensated for. For this reason,
Conventional anti-logarithmic amplifiers use a temperature-sensitive resistor whose resistance value changes in direct or inverse proportion to temperature to cancel out the temperature T in the characteristic equation, but originally a temperature-sensitive resistor has a temperature-resistance coefficient. is nonlinear, and even if various combinations are tried, it is impossible to completely match the desired temperature compensation characteristics over a wide temperature range. Moreover, the resistance values and temperature coefficients of temperature-sensitive resistors vary widely, and even if it happens that one resistor can be temperature-compensated, if a large number of resistors are produced, it will not be possible to completely compensate for the temperature of all of them. Furthermore, in order to achieve perfect temperature compensation, selecting a temperature-sensitive element can be expensive. Therefore, although the inverse logarithmic amplifier plays an important role in music synthesizers, it is not possible to completely compensate for the temperature including variations, so even if a VCO with high temperature stability is used, music・The temperature stability of the synthesizer pitch had to be poor. The present invention has been made in order to eliminate the above-mentioned drawbacks, and by inputting an arithmetic differential voltage that changes in proportion to temperature and corresponds to the sound source frequency to an anti-logarithmic amplifier, it is possible to generate an arithmetic voltage that corresponds to the sound source frequency. The present invention provides a sound source device for an electronic musical instrument that can obtain a geometric electric signal (current or voltage) that is stable against temperature changes.

Examples thereof will be described below with reference to the drawings.

In FIG. 1, 1 is a temperature-sensitive voltage generating circuit that generates a voltage VT that changes in proportion to the temperature T (0K). 2 is a pitch control voltage generation circuit that generates a pitch control voltage Vpc that changes in proportion to the temperature TCK) and corresponds to the sound source frequency f; A pitch shift voltage generation circuit 21 that generates a pitch shift voltage Vps that changes in proportion to the temperature T and whose level setting is variable.
2, and an adder circuit 23 which adds the scale voltage VK and pitch shift voltage Vps at appropriate levels to generate a pitch control voltage Vpc.

3 is an antilogarithmic amplifier using a semiconductor PN junction as an antilogarithmic conversion element, and the antilogarithmic conversion characteristic is not temperature compensated.

The anti-logarithmic amplifier 3 performs anti-logarithmic conversion on the pitch control voltage Vpc and outputs a current 1c-Aexp (BVpc/T). However, A. B is a constant that is not related to temperature T, and T indicates the gel pin temperature (0K). 4 is a current controlled oscillator;
It oscillates at a sound source frequency f that is directly proportional to the input current 1c.

Next, the operation of the embodiment shown in FIG. 1 will be briefly explained.

The anti-logarithmic conversion characteristic of the anti-logarithmic amplifier 3 which is not temperature compensated explicitly includes the temperature T as described above, and has a large temperature dependence.

If an input voltage that cancels out this large temperature dependence is applied to the input of the inverse logarithmic amplifier 3, the output current 1c becomes stable against temperature changes, and the sound source frequency f, which changes in proportion to the current 1c, also changes with temperature. It becomes stable. This is proved as follows. The pitch control voltage Vpc, which is the output of the pitch control voltage generation circuit 2, is proportional to the temperature T. That is, pitch control voltage VPc is expressed as KT. However, K is a constant that can be set in accordance with the sound source frequency f. As described above, the output current 1c of the antilogarithmic amplifier 3 is expressed as Ic=Aexp(BVpc/T). By substituting VPc=KT into this formula, Ic=Aexp(BK)
As a result, the temperature T disappears. Therefore, the current 1c is stable against temperature changes. Next, an example in which each of the blocks in the example of FIG. 1 is realized by a specific electric circuit will be shown below.

FIG. 2 shows a specific embodiment of the temperature-sensitive voltage generating circuit 1.

11 and 12 are high input impedance differential amplifiers;
Reference numerals 3 and 14 designate a pair of transistors having the same voltage-current characteristics, and reference numerals 15 to 18 designate resistors that are stable against temperature changes.

The resistors that ground the non-inverting inputs of the differential amplifiers 11 and 12 are connected to the input bias current I of the differential amplifiers 11 and 12, respectively.
This is to remove the offset caused by B. Also, a capacitor between each output inverting input of the differential amplifiers 11 and 12, and a capacitor between the output of the differential amplifier 12 and the transistors 13 and 14.
The resistor 19 interposed between the two emitters is used to maintain good frequency stability of the circuit 1. Next, the operation of the temperature sensitive voltage generating circuit 1 will be explained.

The base-emitter voltage of transistors 13 and 14 is V
BE1 and BE2, and the collector currents are ICl and BE2, respectively.
When IC2 is used, the following relational expression holds true if the base voltage and collector voltage are at approximately the same potential. However, ISl,
IS2 is the reverse saturation current of the transistors 13 and 14, k is the Boltzmann constant, q is the amount of electron charge, and T is the Gelpin temperature.

Negative feedback is applied to the differential amplifier 11 through a resistor 18 and transistors 14 and 13, and the differential amplifier 12 is connected to a resistor 19.
Since negative feedback is applied through the transistor 14, the inverting inputs of the differential amplifiers 11 and 12 are both at ground potential. Furthermore, since the input impedances of the differential amplifiers 11 and 12 are sufficiently high, ICl and IC2 are as follows.

The output voltage of the differential amplifier 11 is VT, and the transistor 1
If the base voltage of 4 is VB, then the following holds true. The base of transistor 13 is grounded, and transistors 13 and 14
Since both emitters of are grounded, the following equation holds. If we take the ratio of equations (2) and (1), we get:

Here, since the characteristics of the transistors 13 and 14 are the same, it is sufficient to set ISl=IS2, and the above equation can be approximated as follows.

By substituting equation (6) into equation (7), the following equation is obtained.

(4), (If we take the ratio of equation 3, we get

From equations (5), (8), and (9), holds true.

Therefore, VT becomes as follows.

If the equation (substitution) is rewritten as VT=KIT, K1 becomes a constant that is unrelated to temperature T, and VT becomes proportional to temperature T.

Therefore, the voltage VT is generated at the terminal 10 as a temperature-sensitive voltage that changes in proportion to the temperature. From equation (2), temperature-sensing voltage V
It can be seen that T is determined only by the two resistance ratios R4/R3 and R1/R2 and is independent of the power supply voltage Vcc. This shows that the temperature-sensitive voltage generation circuit 1 has an excellent feature of not being affected by power supply voltage fluctuations, and the temperature-sensing voltage VT is the reference voltage of the subsequent pitch control voltage generation circuit 2. Considering that, this is a big advantage. FIG. 3 shows a specific embodiment of the pitch control voltage generating circuit 2. In FIG.

As shown in FIG. 1, the pitch control voltage generation circuit 2 includes a scale voltage generation circuit 21 and a pitch shift voltage generation circuit 2.
2 and an adder circuit 23. Scale voltage generation circuit 21
are a voltage-current conversion circuit 211 that converts the temperature-sensitive voltage VT into a current 1T proportional to VT, and a key voltage that converts the output current 1T of the voltage-current conversion circuit 211 into an arithmetic voltage VK corresponding to the musical scale frequency. It consists of a generation circuit 212 and a sample/hold circuit 213 that temporarily stores voltage VK.

Of these, the sample-and-hold circuit 213 is a well-known circuit as shown in FIG. 3, and is not directly related to the purpose of the present invention. Therefore, the output voltage VK of the key voltage generation circuit 212 is directly input to the adder circuit 23. This will be explained as a transmission circuit. In the voltage-current conversion circuit 211 of FIG.
Reference numeral 111 is a differential amplifier, which together with surrounding resistors constitutes a known inverting amplifier.

2110 is an output terminal of the inverting amplifier.

2114 to 2116 are stable resistance against temperature changes,
2112 is a high input impedance differential amplifier, 21
13 is a FET (field effect transistor).

FET2ll3, differential amplifier 2112, and resistor 2114 constitute a known current source, and differential amplifier 2
Since the inverting input and non-inverting input of FET 112 are kept at the same potential, the output current 1T appearing at the drain of FET2ll3
is the voltage across the resistor 2115 and the resistance value R of the resistor 2114
, divided by .

The voltage across the resistor 2115 is as follows, because if the gain of the inverting amplifier constituted by the differential amplifier 2111 is 1 G (G is a positive constant), a voltage -GVT is generated at the terminal 2110.

Therefore, the output current 1T of the voltage-current conversion circuit 211 is expressed by the following equation. It is.

From equation (alternative), since VT=KIT, equation (self) is,
becomes.

Since both K1 and K2 are constants unrelated to temperature T, current 1T is proportional to temperature T. In the key voltage generation circuit 212 of FIG. 3, 2121 is a high input impedance differential amplifier, which constitutes a voltage follower that outputs the voltage of the bus bar 2122 with low impedance.

2123 to 2126 have mutually equal resistance values R,
It is a resistor that is stable against temperature changes and is connected in series.

One end of the resistor 2123 is grounded, and one end of the resistor 2126 is connected to the output of the voltage-to-current conversion circuit 211. The key switches are drawn in two directions so that the higher the key switch is located in FIG. 3, the higher the scale frequency. Therefore, the 0th key switch (the key switch whose terminal is grounded) corresponds to the lowest scale frequency. Now, when all the key switches are in the OFF state, an equal voltage RIT is generated between the terminals of two adjacent key switches.

When any one of the key switches is turned on, the terminal voltage of the turned-on key switch is applied to the busbar 2122, converted to a low impedance by a voltage follower, and output. When multiple key switches are turned on at the same time, all of the turned-on key switches are short-circuited by the busbar 2122 and have the same potential, so the key corresponding to the lowest scale frequency among the turned-on key switches
The switch voltage is output. That is, the key voltage generation circuit 2
12 has a function of generating an arithmetic scale voltage with priority given to bass notes. Now, as shown in FIG. 3, if the nth key switch is turned on, the output voltage VK of the key voltage generation circuit 212 is as follows.

Substituting (self) expression into (self) expression, we get NjR,
Since Kl and K2 are constants independent of temperature T, voltage V
K will be proportional to temperature T. The sample and hold circuit 213 is for temporarily storing the output voltage VK of the key voltage generation circuit 212 when the key is turned on and off, but as mentioned above, this circuit is not directly related to the purpose of the present invention. Therefore, it can be treated as a circuit that transmits the voltage VK as it is.

Therefore, the scale voltage generation circuit 21 is as shown in the Ua formula.
It outputs an arithmetic difference voltage VK that changes in proportion to the temperature T and corresponds to the scale frequency. Next, the pitch in Figure 3
The shift voltage generation circuit 22 will be explained.

220 is a three-terminal variable resistor, and the output voltage VT of the temperature-sensitive voltage generation circuit 1 is connected to the third terminal 223, and the output voltage VT of the temperature-sensitive voltage generating circuit 1 is connected to the first terminal 221.
The output voltage VT of the temperature-sensitive voltage generation circuit 1 is input to the differential amplifier 21.
An electric voltage {VT which has been inverted and amplified by an inverting amplifier configured as 11 is applied to each of them.

The output voltage Vps of the pitch shift voltage generating circuit 22 is taken out from the second terminal 222 of the three-terminal variable resistor 220. The pitch shift voltage generation circuit 22 is a circuit for entirely shifting the plurality of scale pitches selected by the scale voltage generation circuit 21. For example, if the pitch shift voltage generation circuit 22 has a three-octave keyboard, When the scale pitch of C3 to C6 is obtained in the state where is zero, by generating the pitch shift voltage Vps for one octave rise, it is possible to obtain the scale pitch of C4 to C7 with the same keyboard. . That is, by manually moving the knob of the three-terminal variable resistor 220 up and down, it is possible to not only transpose to a desired range, but also tune to a desired pitch. Now, returning to FIG. 3, it is shown that pitch shift voltage Vps is proportional to temperature.

If the second terminal 222 is located at a position α times the total resistance value of the three-terminal variable resistor 220 (0≦α≦1), the voltage appearing at the second terminal 222, that is, the pitch shift voltage Vps is expressed by the following formula.

From formula (substitute), VT=KIT, so formula (substitute) is
However, since g(α) - α(1+G) - G, the pitch shift voltage Vps is proportional to the temperature.

g(α) is a linear function of α, and the increase Δg(α) in g(α) with respect to the increase Δα in α is (1+G)・Δα
becomes. Therefore, the increase ΔVps in Vps with respect to the increase Δα in α becomes K,T(1+G)·Δα, and an arithmetic change in α appears as an arithmetic change in Vps. Now, in the pitch shift voltage generation circuit 22,
As the voltage to be applied to the No. 1 terminal 221, the voltage −G is inverted and amplified by the inverting amplifier configured with the differential amplifier 2111.
VT is used, but any voltage with the opposite polarity proportional to VT is sufficient. An inverting amplifier is provided in the pitch shift voltage generating circuit 22 to invert and amplify the temperature-sensitive voltage VT and output it to the first terminal 221. Just apply it.

However, since this is completely wasteful, in FIG. 3, the voltage to be applied to the No. 1 terminal 221 is obtained from the output terminal 2110 of the inverting amplifier in the scale voltage generating circuit 21. Next, in the adder circuit 23 of FIG. 3, 231 to 233 are resistors that are stable against temperature changes, and form a resistance adder circuit.

The output voltage Vpc of the pitch control voltage generation circuit 2 is generated at the connection terminal 20 of the resistors 231-233. From FIG. 3, the voltage Vpc is expressed by the following equation. -VO? i side? Vj?
▲υ? ? It is breath ν.

G4), Substituting equation (to) into equation (5) and arranging it, we get: Since the coefficients before temperature T are all constants unrelated to temperature, pitch control voltage Vpc is proportional to temperature T. Become.

Since the output terminal 20 of the adder circuit 23 is connected to the base of a transistor constituting the subsequent antilogarithmic amplifier 3, it is desirable that the impedance of the terminal 20 is sufficiently smaller than the base input impedance of the transistor.

Furthermore, in the embodiment of FIG. 3, the output impedance of the pitch shift voltage generating circuit 22 is not zero and can be changed manually, so it is convenient for RlO to be sufficiently larger than R8. Therefore, regarding the resistance of the adder circuit 23, R8 is set to be relatively small (practically about 1KΩ or less), and R9 and RlO are set to be relatively large. FIG. 4 shows a specific embodiment of the antilogarithmic amplifier 3. 31 is a differential amplifier with high input impedance, 32 and 33 are a pair of transistors having the same voltage and current characteristics, and 34 is a resistor that is stable against temperature changes.

This is for removing the offset caused by the input bias current IB of the differential amplifier 31. In addition, the differential amplifier 31
The capacitor between the output and inverting input of the differential amplifier 31 and the resistor interposed between the output of the differential amplifier 31 and both emitters of the transistors 32 and 33 are used to maintain good frequency stability of the antilogarithmic amplifier 3. . Next, the operation of the antilogarithmic amplifier 3 will be explained.

The pitch control voltage generation circuit 2 is connected to the base of the transistor 33.
The output voltage Vpc of the transistor 33 is applied as an input, and the current 1c that drives the subsequent current controlled oscillator 4 flows through the collector terminal 30 of the transistor 33. transistor 32
, 33, when the base-emitter voltages are VBE3 and VB, and the collector currents are IR and Ic, respectively, if the base voltage and collector voltage are at almost the same potential, (1),
Similar to equation (2), the following relational expression holds true. However, IS
3 and IS4 are the reverse saturation currents of the transistors 32 and 33, respectively, k is the Boltzmann constant, q is the amount of electron charge, and T is the Gelpin temperature.

Since the differential amplifier 31 is subjected to negative feedback via the resistor and the transistor 32, the inverting input of the differential amplifier 31 is at ground potential. Also, since the input impedance of the differential amplifier 31 is sufficiently high, the IR is as follows. The base of the transistor 32 is grounded, the pitch control voltage Vpc is applied to the base of the transistor 33, and the transistor 32
, 33 are connected, the following equation holds true. (1), if we take the ratio of the l equation, we get:

Here, since the characteristics of the transistors 32 and 33 are the same, it is sufficient to set IS3=IS4, and the above equation can be approximated.

By substituting equation (20 and (1)) into equation (23), we obtain the following equation.The fact that temperature T is included in the exponential term of the equation (present) representing the output current 1c of antilogarithmic amplifier 3 is , antilogarithmic amplifier 3
This shows that it has both anti-logarithmic transformation characteristics and extremely large temperature dependence. Now, by substituting the input voltage Vpc (own) into the formula (Y), we get the formula, and by eliminating the temperature T in the numerator and denominator, the output current 1c of the antilogarithmic amplifier 3 is as follows: It is shown by the formula.

In some cases, it is necessary to use a voltage output type antilogarithmic amplifier as the antilogarithmic amplifier 3, or to use a circuit in which a current output type antilogarithmic amplifier is followed by a current-to-voltage converter as in the embodiment shown in FIG. There is.

In addition, although both the scale voltage generation circuit 21 and the pitch shift voltage generation circuit 22 are used simultaneously in the pitch control voltage generation circuit 2 shown in FIG. 3, either one may be used, and there is no limit to the number. do not have.

For example, when used as a sound source device for an electronic musical instrument without a keyboard, only the pitch shift voltage generating circuit 22 can be used. In other words, the pitch control voltage generation circuit 2 can be said to have the function of a variable gain amplifier (or multiplier) that receives the temperature sensitive voltage VT as an input. The pitch shift voltage generating circuit 22 in FIG. 3 includes one three-terminal variable resistor 220.
is used, but there is no limit to the number. For example, a 3-terminal variable resistor similar to the variable resistor 220 is provided in parallel to the variable resistor 220, and the variable resistor 220 is connected to the pitch. Another 3-terminal variable resistor Z device can be used for coarse adjustment and fine pitch adjustment.

Needless to say, at this time, it is necessary to add one input to the adder circuit 23. In addition, various contents of the pitch shift voltage generating circuit 22 shown in FIG. 3 can be considered.

For example, devices that are often used to change the pitch not manually but by using electrical signals include LFOs (low frequency oscillators) to apply vibrato, and glide effects that temporarily shift the pitch and then gradually return it. Examples include a glide envelope generator for making the pitches vibrate, and various envelope generators for making the pitch move as you wish. Since it is inconvenient that these effects also change with temperature changes, it is necessary to configure the output amplitude of the LFO and various envelope generators to change in proportion to the temperature T. An example for this purpose is shown below. FIG. 5 shows an embodiment in which a glide envelope generator is used in the pitch shift voltage generating circuit 22. The transistor Trl is for capacitor charging, and the transistor Tr2 is for emitter follower. Since the voltage -GVT obtained by inverting and amplifying the temperature-sensitive voltage G is applied to the emitter of the transistor Trl, the voltage -GVT is applied to the terminal 50 as shown in FIG.
When a pulse voltage more positive than T is applied, the output voltage V,
s drops from the ground potential to -GVT, and gradually returns to the ground potential with a time constant CRG. Therefore, the output voltage V
The amplitude of ps becomes -GVT (the VBE of Tr2 is small and can be ignored), and is proportional to the temperature T. FIG. 6 shows an embodiment in which the pitch shift voltage generating circuit 22 uses an analog waveform generator including an LFO and various envelope generators.

51 is an analog waveform generator.

A multiplier 52 outputs a voltage proportional to the product of the output voltage of the analog waveform generator 51 and the temperature-sensitive voltage VT.

Now, when the output amplitude of the analog waveform generator 51 is Va, the amplitude of the output voltage Vps of the multiplier 52 is MVTV
It becomes a. However, M is a multiplication constant that is not related to temperature. Therefore, the output voltage Vps changes in proportion to the temperature. Figure 7 shows the pitch shift voltage generation circuit 22.
An embodiment using a digital signal output waveform generator including an LFO and various envelope generators is shown below.

53 is a waveform generator that outputs a 4-bit digital signal, and outputs a binary signal corresponding to the amplitude of the output voltage Vps from Q1 to
Output to Q4.

54 is a 4-bit D/A converter using a well-known R2R ladder resistor network.

541 is a differential amplifier for current-to-voltage conversion.

S1 to S4 are current switches whose switching is controlled by the outputs Q1 to Q4 of the waveform generator 53, respectively. D
Temperature sensitive voltage VT as the reference lens voltage of /A converter 54
is given, the currents flowing through the current switches S1 to S4 are the same. Current switch Sn (n=1 to 4
), the output Qn (n-1 to 4) of the waveform generator 53 is "1".
”, it is connected to the inverting input side of the differential amplifier 541, and Q
When n is [0], it is connected to the ground side. Therefore, Qn
If it represents the numbers 1 and O corresponding to the logics "1" and "O", then the output voltage Vps is as follows. Since the coefficient of VT is a constant that is not related to temperature, voltage Vps changes in proportion to temperature T. In the embodiment shown in FIG. 7, a 4-bit digital signal is used for convenience of explanation, but it is clear that the embodiment can be realized without any restriction on the number of bits. The embodiments shown in FIGS. 3, 5, 6, and 7 have been described above as embodiments of the pitch shift voltage generation circuit 22, but it is not necessary to use each of them independently, and any number of them may be used at the same time. They can be combined and configured in parallel.

As described above, the present invention eliminates at once the difficulty of temperature compensation that an inverse logarithmic amplifier has for converting an arithmetic level pitch control voltage to a corresponding geometric pitch, and Furthermore, since temperature compensation can be performed perfectly and without any variation without any adjustment, it is extremely valuable because it can significantly improve the temperature stability of the pitch (sound source frequency) of electronic musical instruments, especially music synthesizers.

[Brief explanation of drawings]

Fig. 1 is a block diagram of one embodiment of the present invention, and Fig. 2 is a block diagram of an embodiment of the present invention.
A specific circuit configuration diagram of an embodiment of the temperature-sensitive voltage generation circuit 1 shown in the figure,
3 is a specific circuit configuration diagram of an embodiment of the pitch control voltage generation circuit 2 shown in FIG. 1, FIG. 4 is a specific circuit diagram of an embodiment of the antilogarithmic amplifier 3 shown in FIG. Pitch in Figure 3
A specific circuit configuration diagram of an embodiment in which a glide envelope generator is used as the shift voltage generation circuit, and FIG. 6 is a circuit diagram of an embodiment in which an analog waveform generator is used in the pitch shift voltage generation circuit shown in FIG. 3. , Figure 7 is the pitch-shi J of Figure 3.
FIG. 3 is a circuit configuration diagram of an embodiment in which a digital signal output waveform generator is used in the voltage generation circuit. 1... Temperature sensitive voltage generation circuit, 2... Pitch control voltage generation circuit, 3... Anti-logarithmic amplifier, 4
... Current control oscillator, 21 ... Scale voltage generation circuit, 22 ... Pitch shift voltage generation circuit, 23 ... Addition circuit, 211 ... ...
Voltage-to-current conversion circuit, 212...Key voltage generation circuit, 51...Analog waveform generator, 52...
. . . Multiplier, 53 . . . Waveform generator for digital signal output.

Claims (1)

[Claims] 1. A temperature-sensitive voltage generation circuit that generates a voltage that changes in proportion to the temperature, and a voltage that changes in proportion to the temperature and corresponds to the sound source frequency, using the output voltage of the temperature-sensitive voltage generation circuit as an input. at least one pitch control voltage generation circuit that generates a voltage;
It is equipped with an antilogarithm amplifier using a semiconductor PN junction as an antilogarithmic conversion element and an electric signal controlled oscillator that oscillates at a frequency directly proportional to the level of the control signal, and converts the output voltage of the pitch control voltage generation circuit into the antilogarithm. A sound source device for an electronic musical instrument, characterized in that the electrical signal controlled oscillator is controlled by an electrical signal obtained by anti-logarithm conversion using an amplifier, and the oscillation frequency of the electrical signal controlled oscillator is used as a sound source frequency. 2. As a pitch control voltage generation circuit, a scale voltage generation circuit that receives the output voltage of the temperature-sensitive voltage generation circuit as an input and generates a scale voltage that changes in proportion to temperature and corresponds to the scale frequency, and the above-mentioned temperature-sensitive voltage generation circuit. The pitch voltage generator takes the output voltage of the
It is equipped with a shift voltage generation circuit and an addition circuit that adds the output voltage of the scale voltage generation circuit and the output voltage of the pitch shift voltage generation circuit at an appropriate level, the output voltage of the addition circuit being an output of the pitch shift voltage generation circuit. A sound source device for an electronic musical instrument according to claim 1, which uses a control voltage generation circuit. 3 As a scale voltage generation circuit, a voltage-current conversion circuit that converts the output voltage of the temperature-sensitive voltage generation circuit into a current proportional to the output voltage, and a voltage-current conversion circuit that receives the output current of the voltage-current conversion circuit as input and corresponds to the scale frequency. 3. The sound source device for an electronic musical instrument according to claim 2, further comprising a key voltage generating circuit that generates an arithmetic voltage, and using a scale voltage generating circuit that outputs the output voltage of the key voltage generating circuit. 4 As a voltage-current conversion circuit, an inverting amplifier that inverts and amplifies a DC voltage, a differential amplifier, and a first circuit connected in series.
a second resistor, a third resistor, and a field effect transistor; a connection point between the first and second resistors is connected to a non-inverting input of the differential amplifier; one end and the source of the field effect transistor are connected to the inverting input of the differential amplifier, the output of the differential amplifier is connected to the gate of the field effect transistor, and the output of the inverting amplifier is connected to the second resistor. the other end of the first resistor and the other end of the third resistor are connected to the input of the inverting amplifier, and the output voltage of the temperature-sensitive voltage generating circuit is connected to the input of the inverting amplifier. 4. A sound source device for an electronic musical instrument according to claim 3, using a voltage-current conversion circuit configured to input a current and obtain an output current to the drain of the field effect transistor. 5. As a key voltage generation circuit, both terminals of adjacent key switches of multiple key switches having a common bus bar are connected through resistors with equal resistance values, and the circuit corresponds to the lowest note (or highest note). It has a keyboard with the terminals of the key switch connected to a fixed potential point and a voltage follower, and the output current of the voltage-current conversion circuit is connected to the key switch.
A key voltage generation circuit configured to lead to the terminal of the key switch corresponding to the highest (or lowest) tone of the board, and at the same time convert the busbar voltage when the key is on to impedance conversion with the voltage follower and output it. A sound source device for an electronic musical instrument according to claim 3 or 4, using the following. 6 As a pitch shift voltage generation circuit, a three-terminal variable resistor is provided, and the output voltage of the temperature-sensitive voltage generation circuit and the output voltage of the temperature-sensitive voltage generation circuit are inverted between both terminals of the three-terminal variable resistor. Claims 2 to 3 use a pitch shift voltage generation circuit configured to apply a voltage inverted by an amplifier and output the voltage appearing at the sliding terminal of the three-terminal variable resistor. The sound source device for an electronic musical instrument according to any one of Item 5. 7 Claims 2 to 5 which use a pitch shift voltage generation circuit that outputs an electrical signal having an output amplitude proportional to the output voltage of the temperature-sensitive voltage generation circuit as the pitch shift voltage generation circuit. The electronic musical instrument sound source device according to any one of the items. 8 As a pitch shift voltage generation circuit, a waveform generator that outputs amplitude information of a desired waveform as an electric signal, and an output signal of the above waveform generator and an output voltage of the temperature-sensitive voltage generation circuit are input, and these two Claim 1 which uses a pitch shift voltage generation circuit comprising a multiplier circuit that outputs a voltage proportional to the product of output levels, and configured to output the output voltage of the multiplier circuit. Sound source device for electronic musical instruments. 9 The temperature-sensitive voltage generating circuit includes first and second differential amplifiers, first and second transistors, and seventh, eighth, ninth, and tenth resistors, and the first and second The inverting inputs of the second differential amplifier are connected to a constant voltage source via the seventh and eighth resistors, respectively, and the non-inverting inputs of the first and second differential amplifiers and the ninth resistor are connected to each other. one end and the base of the first transistor are grounded, the collectors of the first and second transistors are connected to the inverting inputs of the first and second differential amplifiers, respectively, and the second differential amplifier is connected to the emitter of the second transistor through a resistor, the emitter of the second transistor is connected to the emitter of the first transistor, and the base of the second transistor is connected to the ninth resistor. and the output of the first differential amplifier is connected to the base of the second transistor via the tenth resistor, so that the output voltage of the first differential amplifier is output. A sound source device for an electronic musical instrument according to any one of claims 1 to 8, which uses a temperature-sensitive voltage generating circuit configured to perform the following. 10 As an antilogarithmic amplifier, a third differential amplifier and a third
, a fourth transistor, and an eleventh resistor, the non-inverting input of the third differential amplifier and the base of the third transistor are grounded, and the inverting input of the third differential amplifier is grounded. is connected to a constant voltage source via the eleventh resistor, the collector of the third transistor is connected to the inverting input of the third differential amplifier, and the output of the third differential amplifier is connected to the resistor. The emitter of the fourth transistor is connected to the emitter of the third transistor through the terminal, and the base of the fourth transistor is a voltage input terminal, and the collector is a current output terminal. A sound source device for an electronic musical instrument according to any one of claims 1 to 9, which uses an inverse logarithmic amplifier configured as follows. 11. A sound source device for an electronic musical instrument according to any one of claims 1 to 10, which uses a current-controlled oscillator that oscillates at a frequency directly proportional to the level of an input current as the electrical signal-controlled oscillator. 12. The sound source device for an electronic musical instrument according to claim 9, wherein a pair of transistors having the same voltage-current characteristics is used as the first transistor and the second transistor. 13. The sound source device for an electronic musical instrument according to claim 10, wherein a pair of transistors having the same voltage-current characteristics is used as the third transistor and the fourth transistor. 14. The sound source device for an electronic musical instrument according to claim 1, wherein the temperature-sensitive voltage generation circuit and the antilogarithmic amplifier are kept in substantially the same temperature equilibrium state.