Amplifier of musical tone signal and output method of waveform of musical tone signal

Abstract

This invention provides an amplifier capable of outputting a waveform of a musical tone signal exceeding the power supply voltage, and a method for outputting the waveform of the musical tone signal. The amplifier includes: a power supply; an input terminal for the musical tone signal; an amplification circuit that amplifies the musical tone signal using the power supply; and a jumper circuit connected to the output terminal of the amplification circuit to output a waveform exceeding the voltage value of the power supply.

Description

Technical Field

[0001] This invention relates to an amplifier for musical sound signals and a method for outputting the waveform of musical sound signals. Background Technology

[0002] Previously, it was known to apply circuits simulating the electrical characteristics of vacuum tubes to guitar amplifiers, and techniques for simulating the unique input-output characteristics of vacuum tube amplifiers were known (e.g., see Patent Document 1). Furthermore, an invention has been proposed that simulates the unique pitch variation of a vacuum tube amplifier by adjusting the filter multiplier according to the level of the guitar input signal (e.g., see Patent Document 2).

[0003] [Existing technical documents]

[0004] [Patent Literature]

[0005] [Patent Document 1] Japanese Patent Publication No. 59-051167

[0006] [Patent Document 2] Japanese Patent No. 3336089 Summary of the Invention

[0007] [The problem the invention aims to solve]

[0008] In existing technologies, even if the waveform shape of a vacuum tube amplifier can be simulated, it is impossible to output a waveform that exceeds the power supply voltage.

[0009] The purpose of this invention is to provide an amplifier capable of outputting a waveform of a musical sound signal that exceeds the power supply voltage.

[0010] [Technical means to solve the problem]

[0011] One embodiment of the present invention is an amplifier, comprising:

[0012] power supply;

[0013] Input terminal for musical signals;

[0014] Amplification circuitry, utilizing the power supply to amplify the musical signal; and

[0015] A circuit, connected to the output of the amplifier circuit, outputs a waveform exceeding the voltage value of the power supply. The circuit is, for example, a jumper circuit.

[0016] Another embodiment of the present invention is a method for outputting the waveform of a musical tone signal, comprising:

[0017] The musical signal is amplified by using a power supply amplification circuit; and

[0018] A waveform exceeding the voltage value of the power supply is output through a circuit connected to the output terminal of the amplifier circuit.

[0019] The amplifier can be structured such that the output of the jumper circuit is connected in series with the speaker load. Furthermore, the amplifier can be structured such that the circuitry includes a jumper control circuit that controls the output waveform of the circuitry.

[0020] Furthermore, the following structure can be adopted: the jumper circuit in the amplifier is a resonance circuit, which includes an inductive load and a capacitive load. Alternatively, the jumper circuit can be a resonant circuit, which includes an inductive load, a first capacitive load, and a rectifier element connected between the inductive load and the capacitive load. Also, the jumper circuit can be a resonant circuit, which includes an inductive load, a first capacitive load, a second capacitive load including a damping element, and a rectifier element connected between the inductive load and the first capacitive load. Attached Figure Description

[0021] Figure 1 This describes the circuit structure of an amplifier (power amplifier) ​​that can be applied to a guitar amplifier.

[0022] Figure 2 This indicates the power supply voltage of the amplifier.

[0023] Figure 3 Example of a jump circuit structure.

[0024] Figure 4 Example of a jump circuit structure.

[0025] Figure 5 Examples of input and output waveforms for a vacuum tube amplifier.

[0026] Figure 6 This represents the input waveform for the jump circuit and the output waveforms from the first jump circuit to the third jump circuit.

[0027] Figure 7 This represents the output waveform of the first jump circuit.

[0028] Figure 8 This represents the output waveform of the third jump circuit.

[0029] Figure 9 This represents the equivalent circuit when the positive input signal is input to the third jump circuit.

[0030] Figure 10 This represents the equivalent circuit when the negative input signal is input to the third jump circuit.

[0031] [Explanation of Symbols]

[0032] 1: Amplifier

[0033] 10: Amplifier Circuit

[0034] 20, 20A, 20B: Jump circuit

[0035] 30: Speaker load Detailed Implementation

[0036] Hereinafter, with reference to the accompanying drawings, an embodiment of the amplifier circuit will be described. The structure of the embodiment is illustrative and is not limited to the structure of the embodiment. Figure 1 This describes the circuit structure of amplifier 1 (amplifier circuit: power amplifier) ​​that can be applied to a guitar amplifier. Amplifier 1 is configured to obtain waveforms similar to those of a vacuum tube amplifier. Figure 2 This indicates the power supply voltage VCC and the power supply voltage VEE.

[0037] Figure 1 In this circuit, operational amplifier IC1, resistors R1 and R2 amplify the input signal e1 received from input terminal t1. Oscillator 12, which outputs pulses of a specified frequency (i.e., the input signal e1), is connected to input terminal t1. The input signal is a musical tone produced by playing an electric guitar connected to a guitar amplifier. Additionally, Figure 1 The amplifier circuit 10 shown is a non-inverting amplifier circuit, but an inverting amplifier circuit can also be used. Capacitor C3 is connected between the positive input terminal of operational amplifier IC1 and input terminal t1, and resistor R4 is connected between the positive input terminal of operational amplifier IC1 and ground GND.

[0038] A speaker load 30 is connected to the output terminal t2 of the amplifier. The speaker load 30 includes the purely resistive component of the speaker unit, i.e., resistance R5, and the parasitic inductive component L2. The speaker unit is the type typically used in a guitar amplifier.

[0039] A jumper circuit 20 (first jumper circuit) is inserted between the amplifier circuit 10 and the output terminal t2. That is, the signal from the amplifier circuit 10 is connected to the speaker load 30 after passing through the jumper circuit 20. The jumper circuit 20... Figure 1 The example shown is a resonant circuit, which includes an inductive load, namely a coil L1, and a capacitive load, namely capacitors C1 and C2. However, as... Figure 3 As shown, a resonant circuit with added damping resistors R6 and R7, i.e., the jump circuit 20A (second jump circuit), can also be used. Alternatively, as... Figure 4 As shown, a jump circuit 20B (third jump circuit) with diodes D1 and D2 as rectifier elements and resistor R3 can also be used.

[0040] Figure 5 This indicates a rectangular wave with a period of 1 kHz ( Figure 4 The output waveform observed at the loudspeaker load when the upper layer is input to the vacuum tube amplifier. Figure 4 (The lower layer). Based on the vacuum tube amplifier, a so-called skip waveform output with the following characteristics was observed.

[0041] (1) During the rise and fall of the waveform, there are particularly large jumps (causing overshoot).

[0042] (2) The peak voltage value (wave height value) of the jump becomes greater than the power supply voltage.

[0043] As Figure 1 The input signal (e1) shown for the amplifier is a rectangular wave with a period of 1 kHz, formed by the positive and negative side waveforms. This is a waveform suitable for observing the characteristics of the so-called attack waveform immediately after the guitar has been played, which is ideal for observing the output musical sound waveform of an electric guitar.

[0044] Figure 6 The input and output waveforms of jump circuits 20, 20A, and 20B are represented. Figure 6 The top level is represented in Figure 1 The waveform at observation point (2), that is, the input waveform for the jump circuit. Figure 6 The second layer from the top and Figure 7 Indicates the use of jump circuit 20 Figure 1 The waveform of observation point (3) in the circuit is the output waveform of the jump circuit 20.

[0045] Relative to the input waveform, the output waveform of the jumper circuit 20 generates a resonant wave (ringing) with multiple peaks during the rise and fall of the waveform. The peak value containing the first resonant peak exceeds the supply voltage (±40 V), producing the so-called jump effect. This is because resonance is caused by L1 and (C1+C2) during the rise and fall of the waveform.

[0046] However, as Figure 7As shown, following the overshoot of the first peak, an undershoot of the first peak and subsequent peaks followed by a second peak occurred, exhibiting a state of fluctuation and decay. As mentioned above, it did not become as... Figure 5 The waveform of the vacuum tube amplifier shown is characterized by particularly large jumps (drops) during the rise and fall of the waveform.

[0047] Figure 6 The output waveform shown on the third layer from the top represents the output waveform of the 20A jump circuit for the input waveform of the top layer (in... Figure 1 The waveform at observation point (3). And the output waveform of jump circuit 20 ( Figure 6 Compared to the second layer from the top, the damping effect formed by resistors R6 and R7 is increased, thereby suppressing the resonance between coil L1 and capacitor C1, and the resonance between coil L1 and capacitor C2.

[0048] However, in the output waveform of the jumper circuit 20A, a second peak following the overshoot and undershoot of the first peak was also generated (resulting in ringing), thus it did not become the output waveform of a vacuum tube amplifier. Figure 5 That produces a waveform with one overshoot and one undershoot.

[0049] Figure 6 The fourth layer (bottom layer) from the top and Figure 8 The output waveform shown represents the output waveform of the jump circuit 20B for the uppermost input waveform (in... Figure 1 The waveform at observation point (3). In the output waveform of the jumper circuit 20B, a resonant wave (overshoot and undershoot) with a first peak is generated during the rise and fall corresponding to the rise and fall of the input pulse. The wave height of the first peak containing the resonance exceeds the power supply voltage (±40 V), resulting in the so-called jump effect.

[0050] Furthermore, compared to jump circuits 20 and 20A, jump circuit 20B exhibits almost no overshoot or undershoot amplitude after the first peak, meaning it produces virtually no ringing. In other words, it achieves a waveform close to that of a vacuum tube amplifier's output waveform.

[0051] Figure 9This describes the equivalent circuit of the jumper circuit 20B when a positive input waveform is applied. The equivalent circuit includes: capacitor C1, which is a first capacitive load; capacitor C2, which is a second capacitive load including resistor R3 as a damping component; and diode D1, which is a rectifier element connected between coil L1 (as an inductive load) and capacitor C1. The operation of the jumper circuit 20B is explained using this circuit, which generates [something] through the resonance of coil L1 with capacitors C1 and C2. Figure 8 The overshoot of the first peak shown. At this time, the resonance between capacitor C1 and coil L1, without passing through damping resistor R3, has a dominant effect. During this period, capacitor C2 is charged with a delayed rate through damping resistor R3.

[0052] After the overshoot of the first peak, the resonance between coil L1 and capacitor C1 causes the undershoot of the first peak and subsequent peaks. However, by delaying the charging of capacitor C2, the undershoot of the first peak and subsequent peaks caused by the resonance formed by coil L1 and capacitor C1 can be suppressed by an integrating circuit including resistor R3 and capacitor C2.

[0053] Figure 10 This represents the equivalent circuit of the jump circuit 20B when a negative input waveform is input to the jump circuit 20B. Figure 10 Structure and Figure 9 When comparing the structures, the functions of capacitors C1 and C2 are swapped, but it operates using the same principle as described when inputting the positive waveform.

[0054] Alternatively, an electronic inductive load or electronic capacitive load, including electronic circuits, can be used instead of the coil L or capacitor C. As described above, the jumper circuits 20, 20A, and 20B of the amplifier 1 according to the embodiment can generate overshoot and undershoot output waveforms exceeding the power supply voltage by utilizing the jumper circuits to correspond to the rise and fall of the input pulse. Furthermore, according to jumper circuit 20A or jumper circuit 20B, ringing can be suppressed to obtain an output waveform approximating the output waveform of a vacuum tube amplifier. The structures shown in the embodiments can be appropriately combined without departing from the intended purpose.

Claims

1. An amplifier, comprising: First power source; Second power source; Input terminal for musical signals; An amplifier circuit amplifies the musical sound signal using the first power supply and the second power supply. as well as A resonant circuit, connected in series between the output terminal of the amplifier circuit and the speaker load, outputs a waveform with a voltage value exceeding that of the first power supply and the second power supply. The resonant circuit includes: An inductor, one end of which is connected to the output terminal of the amplifier circuit, and the other end of which is connected to the speaker load; The anode of the first diode is connected to the other end of the inductor; The cathode of the second diode is connected to the other end of the inductor; The first capacitor has one end connected to the cathode of the first diode and the other end connected to the first power source; A second capacitor, one end of which is connected to the anode of the second diode, and the other end of which is connected to the second power supply; and A resistor, one end of which is connected to the cathode of the first diode and the other end of which is connected to the anode of the second diode.

2. The amplifier according to claim 1, wherein Relative to the input waveform of the musical sound signal, the output waveform of the resonant circuit generates a resonant wave with multiple peaks during the rise and fall of the waveform, and the height of the first peak of the resonant wave exceeds the voltage values ​​of the first power supply and the second power supply.

3. The amplifier according to claim 2, wherein The resonant wave is generated by the inductor, the first capacitor, and the second capacitor of the resonant circuit.

4. A method for outputting the waveform of a musical tone signal, comprising: The musical signal is amplified by using an amplifier circuit that combines a first power supply and a second power supply. as well as A resonant circuit connected in series between the output terminal of the amplifier circuit and the speaker load outputs a waveform with a voltage value exceeding that of the first power supply and the second power supply. The resonant circuit includes: An inductor, one end of which is connected to the output terminal of the amplifier circuit, and the other end of which is connected to the speaker load; The anode of the first diode is connected to the other end of the inductor; The cathode of the second diode is connected to the other end of the inductor; The first capacitor has one end connected to the cathode of the first diode and the other end connected to the first power source; A second capacitor, one end of which is connected to the anode of the second diode, and the other end of which is connected to the second power supply; and A resistor, one end of which is connected to the cathode of the first diode and the other end of which is connected to the anode of the second diode.

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