JPH07129164A - Effect generating device - Google Patents

Abstract

PURPOSE:To provide an effect generating device which can control change of the delay time of a filter including a delay in any desired manner. CONSTITUTION:A musical sound signal is fed to a com-filter consisting of an adder 2, delay 3, and factor multiplier 4. A level sensing circuit 5 and a factor multiplier 6 control the delay time of the delay 3. The level sensing circuit 5 is fed with musical sound signal (original sound signal) and emits the level data corresponding to the level of this fed sound signal, and the factor multiplier 6 multiplies this level data with a sensitivity factor, and gives the result to the delay 3 as a read address correction value. Depending upon positive/negative of the sensitivity factor, the delay time can be controlled from long to short and vice versa in accordance with the magnitude of the original sound signal level. A longer delay time lowers the filtrating frequency characteristics and sinks the swelling frequency, while a shorter delay time heightens the filtrating frequency characteristics and lifts the swelling frequency. Thereby the flanging effect given to musical sounds is no more monotonous.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a filter including a delay (delay circuit) such as a comb filter to change the frequency spectrum of a musical tone signal and to give the musical tone a flanging effect and the like. Regarding

[0002]

2. Description of the Related Art As an effect device for giving an effect to a tone signal, various ones have been put into practical use, and among them, there is an effect device called a flanger.
The flanger is an effect device that uses a comb filter including a delay, and is a device that changes the tone color of a musical sound by changing the delay time of the comb filter from moment to moment. By passing a musical tone signal through this comb filter, it is possible to create a timbre effect such as a rising and falling sound of a jet aircraft. FIG. 8 shows a block diagram of a conventional flanger. This flanger is of a digital type, and the read address of the RAM forming the delay is LFO.
The flanging effect is produced by periodically moving it with a (low frequency oscillator).

[0003]

However, such a conventional flanger cannot reflect the intention of the performer in real time, and is fixed by the low frequency signal output by the LFO regardless of the input musical tone signal. Only the flanging effect of the cycle was obtained, and it was monotonous.

An object of the present invention is to provide an effect device capable of arbitrarily controlling a change in delay time of a filter including a delay.

[0005]

As shown in FIG. 1, the present invention includes a filter B including a delay A for filtering an input musical tone signal, and a delay of the delay A depending on the level of the input musical tone signal. Delay time control means C for controlling time
It is characterized by having.

[0006]

In FIG. 1, the inputted tone signal is inputted to the filter B including the delay A. A part of the higher harmonic components of the tone signal is selectively emphasized / attenuated by the filter B, and the frequency spectrum is changed (the tone color is changed).
Is output. The delay time control means C controls the delay time of the delay A according to the level of the tone signal. Delay A
When the delay time changes, the filtering characteristic of the filter B changes, so the degree of change of the frequency spectrum also changes, and the tone color of the output musical tone signal also changes. In this way, since the filtering characteristic of the filter B changes in accordance with the level change of the input musical tone signal, the change of the tone color becomes easy to hear in conjunction with the level change of the musical tone signal. Further, the player can control the magnitude of the tone color change by manipulating the level of his or her own pronunciation.

[0007]

2 is a block diagram of an effect device according to an embodiment of the present invention. This effect device is an effect device called a flanger, in which the delay 3 corresponds to the delay A in FIG. 1, and the adder 2, the delay 3 and the coefficient multiplier 4 correspond to the filter B in FIG. The level detection circuit 5 and the coefficient multiplier 6 correspond to the delay time control means C.

A digital tone signal (original tone signal) inputted from the outside is given to the amplifier 1, the level detection circuit 5 and the coefficient multiplier 9. The signal amplified by the amplifier 1 is given to the delay 3 via the adder 2. Delay 3
Is composed of a RAM, and the data of the tone signal is written into a write address to be sequentially added according to a sampling clock, and the data is read from a read address delayed by a predetermined number from the write address. The read data is input to the coefficient multiplier 4 and the coefficient multiplier 7. The coefficient multiplier 4 multiplies the input signal by the coefficient Feedback for setting the feedback amount and returns the result to the adder 2. Further, the coefficient multiplier 7 has a coefficient Effect Level that determines the strength of the flanging effect.
Is input, and this is multiplied by the signal and output to the adder 8. On the other hand, the original sound signal is also input to the adder 8 via the coefficient multiplier 9. The coefficient multiplier 9 multiplies the original sound signal by the coefficient Direct Level for controlling the level of the original sound signal and outputs the result to the adder 8. The adder 8 adds the input original sound signal and the signal on the delay 3 side and outputs the result to the outside.

On the other hand, in the delay 3, the delay amount of the read address with respect to the write address is corrected according to the input level of the original sound signal. The level detection circuit 5 detects the input level of the input original sound signal. The detected level data is input to the coefficient multiplier 6. The coefficient multiplier 6 multiplies this level data by the sensitivity coefficient Sensitivity and then inputs it to the delay 3 as a correction value of the read address. The delay 3 has a read address calculation circuit, combines this correction value with a reference delay amount, and generates a read address based on the combined value and the write address at that time. The delay 3 outputs the data read from the read address to the coefficient multipliers 4 and 7.
As the sensitivity coefficient Sensitivity, either positive or negative value can be set. If a positive value is set, the read address is moved backward (increasing the delay amount) and increasing the delay time as the input level of the original sound signal increases, as shown in FIG. Also,
If a negative value is set, the read address is moved forward (the delay amount is reduced) and the delay time is shortened as the input level of the original sound signal increases, as shown in FIG.

When the delay time increases, the valley (dip point) moves to the lower frequency side as shown in FIG. 4 (the first dip point Cf0 is Cf0 = 1 / 2T (T:
Delay time). ) The frequency of swelling becomes low. Further, when the delay time becomes short, the frequency of the valley moves to the high frequency side as shown in the figure, and the frequency of the swell increases. Therefore, when the input level and the delay time are made to have a positive correlation as shown in FIG. 3, the delay time and the frequency have an inverse relationship, so that the input level and the frequency of the swell are reversed as shown in FIG. 5B. Become. On the other hand, if the input level and the delay time are negatively correlated as shown in FIG.
As shown in (C), the input level and the undulating frequency envelope match. Note that FIG. 5A shows the envelope of the musical tone of the attenuation system, and FIGS. 5B and 5C show the delay time (Delay) when the delay time of the delay 3 is controlled by this envelope and Frequency (F
req. ) Shows the change. As described above, in this embodiment, since the envelope of the input level matches the delay time or the frequency of the swell, when this effect device (effector) is used in a guitar, flanging is performed according to the picking strength. The effect is controlled, and the jet speed effect, etc. can be produced according to the player's intention.

The coefficient Feedbac of the coefficient multiplier 4
By increasing or decreasing k, the frequency selection characteristic of the comb filter changes. That is, as the Feedback is increased, the dip point becomes larger and the mountain becomes sharper, as shown in FIG. 6, and the Unri frequency is emphasized. It is appropriate that the delay time of the delay 3 is limited to about 2 to 3 ms at the maximum, and the delay time is increased or decreased. Although the delay time is changed in correlation with the input level of the original sound signal in the above embodiment, the delay time is set by the output of the LFO and the frequency of the LFO is controlled according to the input level of the original sound signal. You may do it. Further, although the RAM is used as the delay 3 in the above embodiment, a shift register may be used.

Further, although the flanger has been described in the above embodiment, the present invention can be applied not only to the flanger but also to any effect device having a filter using a delay. Other effect devices using a filter using a delay include, for example, a chorus device and a pitch change device, and FIG. 7 shows an explanatory view of the chorus device. FIG. 1A is a block diagram of the chorus device. This device uses LFO for delay RAM
This delay R by modulating the read address of
The pitch of the tone signal read from the AM (pitch:
Pitch). By mixing the read out musical tone signal and the original tone signal, the device obtains an effect that a plurality of people are playing. By changing the frequency and level of this LFO according to the input level of the original sound signal, it is possible to obtain a varying chorus effect. Further, as shown in FIG. 3B, the pitch change of the musical tone signal read from the delay RAM differs depending on the oscillation waveform of the LFO. One may be selected.

[0013]

According to the present invention, since the delay time can be controlled according to the input musical tone signal and the filtering characteristic of the filter can be changed, the degree of effect and the sound volume (level) of using this filter can be improved. Can be linked, and a pleasant effect can be given to the listener. Further, the performer can freely control the degree of the effect by changing the intensity of the performance by performing the performance operation.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of the present invention.

FIG. 2 is a block diagram of an effect circuit (flanger) which is an embodiment of the present invention.

FIG. 3 is a diagram showing a correlation between an input time and a delay time of the same effect circuit.

FIG. 4 is a diagram showing frequency characteristics of a comb filter of the same effect circuit.

FIG. 5 is a diagram showing a relationship among an input level of the same effect circuit, a delay time, and a swell frequency.

FIG. 6 is a diagram showing a change in frequency characteristic with an increase in feedback amount of a comb filter of the same effect circuit.

FIG. 7 is a diagram for explaining another embodiment (chorus device) of the present invention.

FIG. 8: Block diagram of conventional flanger

[Explanation of symbols]

 2-Adder 4-Coefficient (Feedback) Multiplier 3-Delay Circuit 5-Level Detection Circuit 6-Coefficient (Sensitivity) Multiplier

Claims (1)

[Claims] 1. An effect device comprising a filter including a delay circuit for filtering an inputted musical tone signal, and a delay time control means for controlling a delay time of the delay circuit, wherein the delay time control means comprises the input. An effect device which is a means for controlling the delay time according to the level of the generated musical tone signal.