JPH0738960Y2 - Delay device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a delay device used in an electronic musical instrument.

[Prior art]

In a conventional electronic musical instrument, a mixer device including a delay circuit as shown in FIG. 3 is known to obtain a reverberation effect and an echo effect. That is, the input signal input from the input terminal passes through the buffer amplifier 1 through one of the two volumes 2 and is input as the original sound to the (−) input side of the mixer 4 through the buffer amplifier 3. A part of the input signal is delayed in phase for a predetermined time by a delay circuit 5 composed of a bucket brigade device (BBD circuit) and is input as an echo sound to a buffer amplifier 6. The echo sound that has exited there passes through the other of the double volume 2 and is also input to the (−) side of the mixer 4 via the buffer amplifier 7. The original sound and the echo sound are mixed and output by the mixer 4. Here, the double volume is wired so that it operates in reverse on the original sound side and the echo sound side. Now, if the output volumes of the buffer amplifiers 1 and 6 are set to the same volume, the mixing ratio of the original sound and the echo sound can be freely set by arbitrarily adjusting the double volume 2.

[Problems of conventional technology]

In the case of the former electronic musical instrument, the original sound is maximum and the echo sound is minimum when the dual volume 2 is fully rotated in one direction, and then the echo sound increases as the original sound gradually decreases when rotated slowly in the opposite direction. And finally, the original sound becomes the minimum and the echo sound becomes the maximum. The maximum value of the original sound and the maximum value of the echo sound have the same sound volume for human hearing. However, the volume when the original sound and the echo sound are mixed by setting the two-series volume 2 in the middle range,
In terms of hearing, the volume is not the sum of the original sound and the echo sound,
The volume is considerably lower than the sum of them. This volume decrease tendency becomes larger as the mixing ratio of the original sound and the echo sound becomes equal to 1, and becomes smaller as the mixing ratio becomes closer to either the original sound or the echo sound. Therefore, when setting the double volume 2 in the middle range, a separate master volume is set up to compensate for this decrease in volume, and the final volume is adjusted each time the mixing ratio of the original sound and the echo sound changes. I tried to increase or decrease. This has a drawback that the operation is troublesome.

[Purpose of device]

It is an object of the present invention to provide a delay device for an electronic musical instrument in which the volume of the mixed sound of the delayed sound (echo sound) and the original sound does not change in the final output even if the mixing ratio of the original sound is changed.

[Key points of device]

The point of this invention is to delay the original sound signal and output an echo sound signal, an operational amplifier, a variable resistor (R) consisting of two fixed side ends and a slider, the original sound signal,
And a circuit network having a first input end to which one of the echo signals output by the delay means is input and a second input end to which the other signal is input, , A first input of the network is connected to an inverting input of the operational amplifier via a _first resistor (R ₁ ),
A second input terminal of the network is connected to a non-inverting input terminal of the operational amplifier via a second resistor (R ₃ ), and one fixed side end of the variable resistor is an output terminal of the operational amplifier. The other fixed side end is connected to the second input end via the third resistor (R ₅ ), the output end of the slider is connected to the inverting input end of the operational amplifier, and the non-inverting input end of the operational amplifier is connected. The reason is that it is grounded via the fourth resistor (R ₄ ).

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In FIG. 1, 10 is a bucket brigade circuit (hereinafter referred to as BB
D circuit), the delay time is determined by the frequency of the control clock signal CL. The output of the delay circuit 10 is input to the buffer amplifier 14, and the output terminal of the buffer amplifier 14 is a resistor.
R ₁ , R ₂ , R ₃ and R ₄ are connected in series in order and
The end of R ₄ is grounded. The output terminal of the other buffer amplifier 16 is connected to the connection point of the resistors R ₂ and R ₃ , and one end of the resistor R ₅ is connected to this connection point. Reference numeral 12 denotes an operational amplifier. The (-) input terminal of the operational amplifier 12 is connected to the connection point of the resistors R ₁ and R ₂ and to the slider 13 of the variable resistor R having a linear characteristic. There is. One end of the variable resistor R on the fixed side is connected to the other end of the resistor R ₅ , and the other end of the fixed side is connected to the output end of the operational amplifier 12. Further, the (+) input terminal of the operational amplifier 12 is connected to the connection point between the resistors R ₃ and R ₄ , and the variable resistor R serves as a feedback resistance of the operational amplifier 12. Input signals are simultaneously applied to the delay circuit 10 and the buffer amplifier 16. In this way, the operational amplifier 12
And the resistor networks R _{1 to} R ₅ and R constitute a mixing circuit 15 which receives buffer amplifiers 14 and 16 as inputs.

In this way, the musical sound and voice input signals are delayed by the delay circuit 10 for a predetermined time, and the voltage V ₁ is output from the buffer amplifier 14 and input to the mixing circuit 15. This delay time is determined by the frequency of the clock signal CL, and the phase delay with respect to the input signal is determined by the frequency of the input signal.

On the other hand, the input signal is amplified by the buffer amplifier 16 and outputs the voltage V ₂ which is input to the mixing circuit 15. Delay circuit here
The signal passing through 10 is the echo sound signal, and the buffer amplifier
The signal passing through V ₂ is the original sound signal.

Assuming that the operational amplifier 12 of the delay device operates ideally, its transfer characteristic is calculated by assuming that the output voltage is V _o and the position of the slider 13 is x, (+) Input end term (-) Input end term Becomes (However, o ≦ x ≦ R) If the slider 13 is at the right end, that is, x = R, the formula is Then, only the component of the original sound signal V ₂ is output. On the other hand, when the slider 13 is at the left end, that is, x = 0, the formula is However, in order to output only the component of the echo signal V ₁ , the coefficient of V ₂ should be 0, If we transform this equation To get At this time, the output signal V ₀ is Therefore, it surely becomes the component of only the echo signal V ₁ . Therefore, only one of the original sound signal and the echo signal can be output by setting the slider 13 at either end. Make sure that the output voltage of only one of these components is equal to each other If the amplification factors of the buffer amplifiers 14 and 16 are determined so that
The 15 output signals can be at the same level. In fact the value R = 50K present inventor has satisfy the _{formula, R 1 = 15K, R 2} = 15K, R 3 = 10K, R 4 = 14K, R 5 = 18KΩ
Set to. Then the formula is Becomes Further, buffer amplifiers 14 and 16 satisfying the formula were selected, and the formula was input to the computer and plotted to obtain a graph as shown in FIG. The horizontal axis is the slider x value x
The vertical axis represents the output voltage of the operational amplifier 12. Now, the original sound signal voltage V ₂ is standardized and fixed to a predetermined value, and the output voltage V ₀ of the mixer circuit 15 output only by the echo signal voltage V ₁ component is plotted with the value x of the slider 13 as a variable. A graph B indicated by a chain line is obtained. As is known from the equation, the graph B is a linear equation with a negative slope, and gives the output voltage of the equation when the slider 13 is at the left end and x = 0 (normalized and set to "1" in the figure). . When the value of x, that is, the position of the slider 13 is gradually moved from the left end to the intermediate range and the right end, the echo signal V ₁
The output voltage V _0, which depends only on the component, decreases linearly, and finally becomes “0” when the slider 13 is at the right end and x = R.

Next, the echo signal voltage V ₁ is standardized and fixed to a predetermined value, and the output voltage V ₀ of the mixer circuit 15 output only by the original sound signal V ₂ is plotted with the value x of the slider 13 as a variable. The graph A shown is obtained. As is known from the equation, the graph B is a quadratic equation and a quadratic curve with a negative coefficient,
When the slider 13 is at the right end and x = R, the output voltage of the formula is given (normalized and set to "1" in the figure). x = R
Then, when the position of the slider 13 is gradually moved from the right end to the left end of the intermediate range, a quadratic curve having a maximum value is obtained according to the formula, and the output voltage V ₂ which depends only on the original sound signal V ₂ component is obtained. ₀ increases once, and after applying the maximum voltage, 2
It sharply decreases along the following curve, and finally becomes "0" when the slider 13 is at the left end and x = 0. The trend of the maximum value and the increase / decrease rate of this graph B is that the resistors R ₁ , R ₂ , R ₃ ,
It can be set arbitrarily by changing the values of R ₄ , R ₅ and R. A graph C is a graph obtained by adding the graph A and the graph B, that is, when the original sound signal V ₂ and the echo signal V ₁ are mixed by the mixer circuit 15 and the value x of the slider 13 is changed, the original sound signal V _{2 of the} formula is changed. _{6 is} an output graph of the output voltage V ₀ of the mixer circuit 15 depending on both the echo signal V ₁ and the echo signal V ₁ . x =
When the position of the slider 13 is gradually moved from R to the middle range from R, V ₀ is calculated as x, V ₁ and V ₂ according to the formula.
It gradually increases from "1" as a variable of, and gives the maximum output at a predetermined value in the intermediate range of x, and further moves the position of slider 13 to the left end from this intermediate predetermined value, and this time, it suddenly increases. At the same time, the signal output voltage V ₀ decreases toward "1". The movement of the slider 13 of the variable resistor R changes the mix ratio of the original sound and the echo sound, and also changes the signal output voltage V ₀ . The increasing voltage at this time acts so as to compensate for the decreasing tendency of the sound volume appearing in the intermediate range where the mix ratio of the original sound and the echo sound is equal to "1", and the signal output voltage of the graph C is the same as that of the graph D in the auditory sense. It becomes the auditory characteristic shown. Therefore, even if the mixing ratio of the original sound signal and the echo sound signal is changed, the audible volume does not change and natural music can be emitted.

When the delay circuit 10 composed of the BBD circuit is made into a plurality of channels, or when the clock CL signals are input in two or more phases, the volume reduction tendency characteristic of the mixing sound in the sense of hearing becomes different. By changing the values of R ₁ , R ₂ , R ₃ , R ₄ and R, the characteristic curve of the graph A is changed, and thus the shape of the characteristic curve of the graph C is changed so as to compensate for the decreasing tendency, so that the same characteristics are obtained. The effect can be obtained. Furthermore, in this embodiment, the original sound signal output V ₂ has a quadratic curve characteristic and the echo sound signal output has a linear linear characteristic, but the opposite, that is, the echo sound signal output has a quadratic curve characteristic, and the original sound signal output is The buffer amplifiers 14 and 16 and the resistor networks R _{1 to} R ₄ may be connected so as to obtain a linear linear characteristic.

[Effect of device]

As described above, the present invention has a delay means for outputting an echo sound signal obtained by delaying an original sound signal, an operational amplifier, a variable resistor (R) including two fixed side ends and a slider, an original sound signal, and A first input end to which either one of the echo signals output by the delay means is input,
A network having a second input to which the other signal is input, the first input of the network being connected to the inverting input of the operational amplifier via the _first resistor (R ₁ ). Connected,
A second input terminal of the network is connected to a non-inverting input terminal of the operational amplifier via a second resistor (R ₃ ), and one fixed side end of the variable resistor is an output terminal of the operational amplifier. The other fixed side end is connected to the second input end via the third resistor (R ₅ ), the output end of the slider is connected to the inverting input end of the operational amplifier, and the non-inverting input end of the operational amplifier is connected. Since it is grounded via the fourth resistor (R ₄ ), the echo sound and reverberation sound can be strengthened while the musical sound is proceeding, and conversely the original musical sound can be strengthened.
Even if an operation of appropriately mixing these is performed, the volume is always kept constant and the naturalness of the musical sound can be emitted. Further, since the circuit is simple, it can be widely used in electronic musical instruments.

[Brief description of drawings]

FIG. 1 is an overall circuit configuration diagram showing an embodiment of the present invention,
FIG. 2 is an output signal characteristic diagram of the delay device of the present invention, and FIG. 3 is a conventional circuit configuration diagram. 10 ...... delay circuit, 12 ...... operational amplifier, 13 ...... slider, 14, 16 ...... buffer amplifier, 15 ...... mixing circuit, R ...... variable resistor, CL ...... clock, R ₁ to R ₅ ...... resistance Circuit network.

Claims (1)

[Scope of utility model registration request] 1. A delay means for outputting an echo sound signal obtained by delaying an original sound signal, an operational amplifier, a variable resistor (R) comprising two fixed side ends and a slider, the original sound signal, and the delay means. A delay device comprising: a circuit network having a first input terminal to which one of the output echo signals is input and a second input terminal to which the other signal is input; The first input is connected to the inverting input of the operational amplifier via a _first resistor (R ₁ ), and the second input of the network is connected to the inverting input of the second resistor (R ₃ ). It is connected to a non-inverting input terminal of an operational amplifier, one fixed side end of the variable resistor is an output terminal of the operational amplifier, and the other fixed side end is a second resistor via a third resistor (R ₅ ).
To the input terminal of the slider, the output terminal of the slider is connected to the inverting input terminal of the operational amplifier, and the non-inverting input terminal of the operational amplifier is grounded through a _fourth resistor (R ₄ ). .