JP3617112B2 - Effector device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an effector device such as a ring modulator that multiplies an input audio signal by a predetermined oscillator output to change the tone and pitch of the input audio signal.
[0002]
[Prior art]
Most of the effector devices maintain the pitch as it is and change only the timbre. Among these, a ring modulator occupies a specific position. The ring modulator is an effector device that changes not only the timbre of the input audio signal but also the pitch and makes the timbre look like a bell.
FIG. 5 is a block diagram showing a configuration of a conventional ring modulator.
The input audio signal is amplitude-modulated by the multiplier 22 on the basis of the sine wave signal output from the sine wave generator 21, thereby obtaining an output of the frequency of the sum and difference of the frequencies of the two input signals.
If the frequency of the sine wave signal is large, the output frequency will be far from the input, and the tone will be like a bell sound.
[0003]
[Problems to be solved by the invention]
However, the above-described conventional effector device can achieve a certain effect as an effector in that an output far from the input audio signal can be obtained, but if the input pitch is constant, the output pitch is It cannot be denied that the pitch becomes monotonous in that it is constant. For this reason, it is not always satisfactory for a user who further desires the effect of destroying the input sound.
[0004]
The present invention has been made in view of such problems, and an object of the present invention is to provide an effector device capable of eliminating the monotony of the output pitch and further enhancing the destruction effect of the input sound.
[0005]
[Means for Solving the Problems]
An effector device according to the present invention includes a variable frequency oscillator and an envelope follower for obtaining an envelope of an input audio signal, or an envelope generator for obtaining an arbitrary envelope, and modulates the output frequency of the oscillator. The frequency modulation means includes a multiplier that multiplies the input audio signal and the output signal of the oscillator and outputs the multiplication result as an effector output.
[0006]
[Action]
According to the effector device of the present invention, when the input audio signal and the oscillator output are multiplied by the multiplier, the frequency of the oscillator output is also modulated by the frequency modulation means. The pitch of will also change. For this reason, it is possible to eliminate the monotonous pitch of the output sound, and to further enhance the destruction effect of the input sound.
[0007]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of an effector device according to one embodiment of the present invention.
[0008]
The oscillator 1 outputs a signal having periodicity, for example, a sine wave signal. This output is supplied to one input terminal of the multiplier 3. The multiplier 3 multiplies the audio input signal input to the other input terminal and the sine wave signal, and outputs a signal having the frequency of the sum and difference of the two input signals as an effector output. The frequency of the sine wave signal output from the oscillator 1 is controlled by the output of an operator 4, LFO (Low Frequency Oscillator) 5, 6, envelope follower 7 or envelope generator 8. Which of these outputs is used for frequency modulation of the sine wave signal can be selected by the switch 2.
[0009]
The oscillator 1 described above is a variable frequency oscillator, and if the signal to be handled is an analog signal, a VCO (Voltage Controlled Oscillator) is used. When the signal to be handled is a digital signal, the oscillator 1 can use, for example, a waveform generator including a waveform memory unit 11 and an address generation unit 12. The waveform memory unit 11 stores an amplitude waveform of a sine wave. The address generation unit 12 generates a read address when reading the amplitude value from the waveform memory unit 11 at a constant read rate. If the read address interval is reduced, the frequency of the read sine wave is reduced, and if the read address interval is increased, the frequency of the read sine wave is increased. This address increment is supplied from the operation element 4, LFO 5, 6, envelope follower 7 or envelope generator 8 via the switch 2.
[0010]
2 to 4 are diagrams for explaining the operation of the apparatus.
When the switch 2 selects the output of the operation element 4, a sine wave having the frequency f _osc designated by the operation element 4 is output from the oscillator 1. In this case, as shown in FIG. 2, the multiplier 3 obtains an output of the sum and difference frequencies of the audio input signal frequency f ₀ and the sine wave frequency f _osc .
When the switch 2 selects the output of the LFO 5, for example, a sine wave is output from the LFO 5, so that the frequency of the output of the oscillator 1 is modulated into a sine wave as shown in FIG. 3A, for example. As a result, the pitch of the output of the multiplier 3 can be made periodic as shown in FIG. When the switch 2 selects the output of the LFO 5, a triangular wave is output from the LFO 6, so that the pitch of the output of the multiplier 3 can be changed to a triangular wave. In addition, a more complicated periodic change can be obtained by making the LFO waveform into various waveforms using a waveform memory or the like.
[0011]
When the switch 2 selects the output of the envelope follower 7, the pitch of the output signal changes according to the envelope of the audio input signal. For example, if an input envelope as shown in FIG. 4 (a) is obtained from the audio input signal by the envelope follower 7, the output pitch of the multiplier 3 corresponds to this input envelope as shown in FIG. 4 (b). Will change. Therefore, the pitch of the output can be changed depending on the strength of the input sound, such that the pitch changes drastically when the input is large and close to the input sound when the input is small. Further, if a frequency change opposite to that of the input envelope is caused, characteristics opposite to those described above can be obtained. Further, such an input envelope may be used as a trigger, and the output frequency may be changed based on an arbitrary envelope preset in the envelope generator 8.
[0012]
【The invention's effect】
As described above, according to the present invention, when the input audio signal and the oscillator output are multiplied by the multiplier, the frequency of the oscillator output is also modulated. It is possible to eliminate the monotonous change in the pitch of the output sound, and to further enhance the effect of destroying the input sound.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an effector device according to an embodiment of the present invention.
FIG. 2 is a diagram for explaining the operation of the apparatus.
FIG. 3 is a diagram for explaining the operation of the apparatus.
FIG. 4 is a diagram for explaining the operation of the apparatus.
FIG. 5 is a block diagram showing a configuration of a conventional ring modulator.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Oscillator, 2 ... Switch, 3 ... Multiplier, 4 ... Operator, 5, 6 ... LFO, 7 ... Envelope follower, 8 ... Envelope generator, 11 ... Address generation part, 12 ... Waveform memory part.

Claims (2)

A variable frequency oscillator,
An envelope follower for obtaining an envelope of an input audio signal, or an envelope generator for obtaining an arbitrary envelope, and a frequency modulation means for modulating the output frequency of the oscillator;
An effector device comprising: a multiplier that multiplies an input audio signal by an output signal of the oscillator and outputs the multiplication result as an effector output. The frequency modulation means further includes a low frequency oscillator, and further includes a switch for selecting an output of the envelope follower, the envelope generator, or the low frequency oscillator.
The effector device according to claim 1.

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