JPS61269196A - Modulation effect apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a modulation effect device used for obtaining rich performance sounds in electronic musical instruments and the like.

[Summary of the invention]

The present invention provides, in such a modulation effect device, an input musical tone signal that is filtered after passing through a plurality of series of filter means each consisting of a plurality of stages of notch filters each having a different removal frequency connected in series, and then filtering the input musical tone signal to determine the synthesis ratio. By modulating this, rich and natural modulation effects can be obtained with an inexpensive circuit.

[Conventional technology]

In electronic musical instruments, there are unsample effect generating devices, tremolo effect devices, and the like as modulation effect devices that provide rich performance sounds by applying modulation such as timbre modulation and amplitude modulation to musical sound signals.

As this kind of conventional modulation effect device, for example.

As shown in Japanese Utility Model Application Laid-Open No. 54-119336, there is a system in which a BBD (also referred to as a CCD) is used to impart delay time modulation to a musical tone signal.

Such a modulation effect device using a BD is preferable because it can impart a natural and rich modulation effect to musical tones.

[Problems to be solved by the invention]

However, BBDs are generally expensive and also require a clock generator (vC○) to drive them, making such modulation effect devices complex and expensive. There was a problem.

The object of the present invention is to solve these problems and to make it possible to obtain a sufficiently natural modulation effect with an inexpensive circuit.

[Means for solving problems]

Therefore, the modulation effect device according to the present invention includes a plurality of series of filter means to which input musical tone signals are respectively supplied, a modulation signal generation means for generating a modulation signal, and a plurality of series of musical tone signals outputted through each of the above-mentioned filter means. and a modulation means that modulates the synthesis ratio of a plurality of series of musical tone signals synthesized by the synthesis means using the modulation signal, and each of the filter means is removed. 3. 'R(7) 16= f, t 6
It is constructed by connecting several tsutu f tsui z and 5 trlls.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a block diagram showing a basic embodiment of a modulation effecting device according to the present invention. Reference numerals 1 and 2 indicate two series of filter means to which input musical tone signals are respectively supplied, each having a removal frequency (nul1 frequency, fl -f3 in block
+fl', f2') are connected in series in multiple stages.

Reference numeral 3 indicates modulation signal generation means for generating an extremely low frequency modulation signal SM such as a sine wave or a triangular wave; 4, two series of musical tone signals SA and SB outputted through the filter means 1 and 2 are generated from the modulation signal generation means 3; 5 is a synthesizing means for synthesizing the two series of musical tone signals SA' and SR' modulated by the modulating means 4.

Note that the modulation means 4 receives two series of musical tone signals (S A, S R
) plays a role in modulating the synthesis rate of

Then, the synthesized musical tone signal So outputted from the synthesizing means 5 is electrically/acoustically converted by a sound system 6 consisting of an amplifier, a speaker, etc., and is generated.

A notch filter, also called a twin-T circuit, is a filter circuit composed of a capacitor and a resistor, as shown in Figure 2, for example, and is determined by f = 1 /RC.
It has a characteristic of removing signals of two frequencies (nu11 frequency).

The filter means 1 and 2 each include a plurality of notch filters connected in series (for example, three or four stages).

For example, the filter means 1 consists of four stages of notch filters with different null1 frequencies connected in cascade, and as shown in FIG.
The filter circuit has a nu11 frequency in Hz, and the filter means 2 has three stages of notch filters with different rlul1 frequencies connected in series, and has a nu11 frequency of 50 as shown in FIG.
0Hz.

The filter circuit has nu11 frequencies at 2 KHz and 8 KHz.

The modulating means 4 and the synthesizing means 5 are, for example, voltage-controlled variable type generators that modulate the amplitude and width of the musical tone signal SA output from the filter means 1 using a signal obtained by inverting the modulating signal SM by an inverting circuit 7, as shown in FIG. Gain amplifier (rVCA)
(abbreviated as J) 8, and a VC that amplitude-modulates the musical tone signal SR output from the filter means 2 with the modulation signal SV1.
A9 and (7) Each output signal SA' of VCA8 and 9
, SR' electrically.

Alternatively, the modulating means 4 and the combining means 5 in FIG. 1 may be configured as shown in the 51st ffff, and the output signals SA' and SR' of the VCAI 3 and the day are separately supplied to the speakers 13 and 14 through the amplifiers 11 and 12, respectively. Alternatively, two series of amplitude-modulated musical tone signals may be acoustically converted and then spatially synthesized.

Alternatively, the modulating means 4 and the combining means 5 may be configured as shown in FIG. .

After performing 1:1 mixing through resistors R1 and R2 of equal resistance in the mixing circuit 16.

Amplitude modulation is applied by the modulation signal SH by the VCA 17, and the output signal Sc and the output signal SR of the filter means 2 are
and a resistor R3 of the mixing circuit 18 having the same resistance value,
The synthesized musical tone signal So may be obtained by performing 1:1 mixing through R4.

This synthesized musical tone signal So is given by a linear equation, where k is the gain of VC:Al1.

5o=(SA-sB)・k(t)+5B=k(t)・S
A+(1-k(t))·SB Also, this circuit is equivalent to the circuit shown in FIG. 6(b). This has the advantage that only one VCA is required.

The characteristics of the filter means 1 and 2 are shown in FIG. 3 (A).

When configured as shown in (b) and employing the circuit shown in FIG. 6 as the modulating means 4 and the synthesizing means 5, the overall frequency characteristic of the synthesized musical tone signal So is as shown in FIG. 7, for example. It changes like this.

As a result, a sufficiently complex and natural-looking modulation effect can be created at t5.
It will be done. Moreover, since an expensive element such as a BBD and its driving circuit are not used, it can be provided at low cost.

By the way, the number of series of filter means is not limited to 2 series, but may be 3 series.
It may be more than one series. For example, in the case of 3 series, the modulation means and the synthesis means amplitude modulate the outputs of the 3 series of filter means using 3 series of modulation signals whose phases are shifted by 120 degrees, respectively, and then synthesize (electrically synthesize) or spatial synthesis).

Further, it is sufficient that the number of null1 frequencies of each filter means is two or more.

Furthermore, as shown in FIG. 4 or FIG. 5, when a VCA is provided as a modulation means for each filter series, the order of the filter means and the VCA may be reversed.

In short, a modulation means such as a VCA may be provided to modulate the synthesis ratio of a plurality of musical tone signals.

FIG. 8 is a circuit diagram showing a specific circuit example of the modulation effecting device according to the present invention, and parts corresponding to those in FIG.

Note that 20 is a low-pass filter having a cutoff frequency of 200 Hz, for example, and the musical tone signal passed through this filter is also electrically synthesized by the synthesizing means 5.

〔Effect of the invention〕

As explained above, the modulation effect device according to the present invention does not use an expensive element such as a BBD, but includes a plurality of filter means configured by cascade-connecting notch filters, and each filter through the filter means. Since the musical tone signal is composed by a means of synthesizing the musical tone signal by modulating the synthesis ratio, it can be provided at low cost, and moreover, the frequency components of the musical tone generated by an electronic musical instrument, etc. are manipulated in a complicated manner to obtain a natural and rich modulation effect. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a basic embodiment of a modulation effect device according to the present invention, FIG. 2 is a circuit diagram showing an example of the configuration of a notch filter, and FIGS. 2. FIGS. 4 to 6 are circuit diagrams showing different configuration examples of the modulation means and synthesis means, respectively. FIG. 7 is a diagram showing changes in the overall frequency characteristics of the synthesized musical tone signal. , FIG. 8 is a circuit diagram showing a specific circuit example of the modulation effect device according to the present invention. 1.2... Filter means 3... Modulation signal generation means 4... Modulation means 5... Synthesis means 6.
...Sound system 7,15...Inversion circuit 8.
9.17...Voltage controlled variable gain amplifier (VCA) 10...Synthesizing circuit Is, 1B...Mixing circuit Figure 4 Other examples of W4 threat synthesis means Figure 6 Changes in overall frequency characteristics Figure 7

Claims (1)

[Scope of Claims] 1. A plurality of filter means to which input musical tone signals are respectively supplied, a modulation signal generation means for generating a modulation signal, and a synthesis method for synthesizing the plurality of series of musical tone signals outputted through each of the filter means. and modulation means for modulating the synthesis ratio of a plurality of series of musical tone signals synthesized by the synthesis means, using the modulation signal, and each of the filter means is composed of a plurality of notch filters each having a different removal frequency. A modulation effect device characterized in that it is configured by vertically connecting stages.