Pickup circuit and microphone

Abstract

The utility model discloses a pickup circuit and a microphone, and the scheme of the utility model is based on a pickup sound head, under a fixed polarization voltage, four paths of signals are generated through two heart-shaped directional signal circuits for output, and the four paths of signals are used for cooperating with a rear-end tuning device to be combined into directional signals of any requirements. The operation difficulty of the front-end pickup device during pickup deployment can be reduced, and convenience is brought to synthesis and adjustment of the rear-end tuning device at the same time.

Description

Technical Field

[0001] This utility model relates to the field of audio technology, specifically to sound pickup circuit technology. Background Technology

[0002] Currently, most common directional microphones typically use dual crystal capsules, and achieve multiple directional characteristics by changing the polarization voltage of the capsule diaphragm.

[0003] In this scheme, which achieves multiple polarizations of a microphone by changing the polarization voltage of the microphone diaphragm, the corresponding polarization is directly generated and output by the microphone's pickup circuit. This means that the microphone can only output a fixed polarization signal to the back-end mixing equipment, making it impossible for the back-end mixing equipment to adjust the polarization through signal synthesis or other processing methods.

[0004] Therefore, in order to achieve high-quality sound pickup, the deployment of various directional microphones in the pickup area and direction, as well as the adjustment of polarization voltage, must be precise; which requires the sound pickup personnel to have a great deal of experience.

[0005] Therefore, providing a user-friendly multi-directional microphone solution is a problem that urgently needs to be solved in this field. Utility Model Content

[0006] To address the issue that existing directional microphones require professional operation and are not user-friendly, the purpose of this invention is to provide a pickup circuit solution that can generate audio signals with arbitrary directional characteristics that can be combined in the back-end mixing equipment. This eliminates the need for professional polarization voltage adjustment and pickup orientation deployment, greatly improving the ease of use of microphones using this pickup circuit solution.

[0007] To achieve the above objectives, this utility model provides a sound pickup circuit, which includes an audio input module, an audio amplification module, and an audio output module.

[0008] The audio input module includes a dual-crystal microphone head and a polarization voltage circuit. The polarization voltage circuit is configured to connect to the middle plate of the dual-crystal microphone head and provide a fixed polarization voltage to the dual-crystal microphone head.

[0009] The audio amplification module includes a first audio amplification circuit and a second audio amplification circuit; the audio output module includes a first audio output circuit, a second audio output circuit, and an output terminal;

[0010] The signal input terminal of the first audio amplifier circuit is connected to the positive diaphragm of the dual crystal microphone, the signal output terminal of the first audio amplifier circuit is connected to the input terminal of the first audio output circuit, and the output terminal of the first audio output circuit is connected to the output terminal to form the first audio output channel.

[0011] The signal input terminal of the second audio amplifier circuit is connected to the inverting diaphragm of the dual crystal microphone, the signal output terminal of the second audio amplifier circuit is connected to the input terminal of the second audio output circuit, and the output terminal of the second audio output circuit is connected to the output terminal to form the second audio output channel.

[0012] In some embodiments of this utility model, the first audio output channel and the second audio output channel can form two sets of four-channel signal outputs.

[0013] In some embodiments of this utility model, the first audio output channel and the second audio output channel simultaneously output cardioid directional signals.

[0014] In some embodiments of this invention, the audio input module is further configured with an impedance transformation element.

[0015] In some embodiments of this utility model, the first audio amplifier circuit and / or the second audio amplifier circuit are mainly based on field-effect transistors.

[0016] To achieve the above objectives, this utility model provides a microphone, which is equipped with the aforementioned sound pickup circuit.

[0017] The pickup circuit and microphone solution provided by this utility model are based on a dual-crystal microphone head and two cardioid microphone circuits to generate four audio signals that can be combined into any desired directional audio signal in the back-end mixing equipment. This eliminates the need for professional polarization voltage adjustment and professional pickup orientation deployment of the front-end microphone, greatly reducing the operational requirements of the microphone and significantly improving the ease of use of the microphone. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0019] Figure 1 This is a schematic diagram of the pickup circuit in the single-capsule microphone of this utility model;

[0020] Figure 2 This is an example diagram illustrating the configuration of the pickup circuit in a single-capsule microphone according to this utility model. Detailed Implementation

[0021] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the following description, in conjunction with specific illustrations, further elaborates on this utility model.

[0022] Compared to existing microphone pickup schemes that directly generate a desired directional audio signal by changing the polarization voltage of the microphone's diaphragm, this invention abandons this method of directly adjusting the front-end pickup device to generate a desired directional audio signal. Instead, it innovatively presents a pickup circuit scheme based on a single pickup head. Under a fixed polarization voltage, it generates four signals through two cardioid directional signal circuits for output. These signals are then combined in the back-end mixing equipment to create any desired directional signal. This reduces the operational difficulty of deploying the front-end pickup device and also brings convenience to the back-end mixing equipment in synthesizing and adjusting the signal.

[0023] See Figure 1 The diagram shown is a schematic diagram of the sound pickup circuit scheme in this utility model.

[0024] Based on the diagram, the pickup circuit 100 is mainly composed of an audio input module 110, an audio amplification module 120, and an audio output module 130 working together.

[0025] The audio input module 110 includes a dual-crystal microphone head 111 and a polarization voltage circuit 112. The polarization voltage circuit 112 is configured to connect to the middle plate of the dual-crystal microphone head and provide a fixed polarization voltage to the dual-crystal microphone head 111. The resulting audio input module 110 can pick up audio signals based on the dual-crystal microphone head 111 under a fixed polarization voltage and simultaneously generate two audio signals, which are then output to the audio amplification module 120.

[0026] The audio amplification module 120 in this pickup circuit 100 includes a first audio amplification circuit 121 and a second audio amplification circuit 122. Correspondingly, the audio output module 130 in this pickup circuit 100 includes a first audio output circuit 131, a second audio output circuit 132, and an output terminal 133.

[0027] Based on this, the signal input terminal of the first audio amplifier circuit 121 in the audio amplifier module 120 is connected to the positive diaphragm of the dual crystal microphone 111, while the signal output terminal of the first audio amplifier circuit 121 is connected to the input terminal of the first audio output circuit 131. At the same time, the output terminal of the first audio output circuit 131 is connected to the output terminal 133, thereby forming a first cardioid directional signal circuit as the first audio output channel.

[0028] The first audio output circuit 131 is configured to form two signal output ports at its output end, and is simultaneously connected to the output terminal 133.

[0029] In the first cardioid directional signal circuit formed here, the first audio amplifier circuit 121 is configured to receive the first audio signal output from the positive diaphragm of the dual crystal microphone 111, amplify it and output it to the first audio output circuit 131, and the first audio output circuit 131 processes the received first audio signal to form two first cardioid directional audio signals for output.

[0030] As further explained, the first audio amplifier circuit 121 is specifically configured to convert the single-ended (positive) high-impedance signal of the microphone into a low-impedance balanced differential signal and output two signals. The two differential signals after conversion are of the same frequency, equal amplitude and have a phase difference of 180 degrees.

[0031] Correspondingly, the first audio output circuit 131 is configured to perform 0dB voltage gain processing on the input signal. Simultaneously, the first audio output circuit 131 is also configured for low impedance output and enhanced load capacity. After processing the two differential signals generated by the first audio amplifier circuit 121, the first audio output circuit 131 can output to the subsequent MIX stage.

[0032] Meanwhile, the signal input terminal of the second audio amplifier circuit 122 in the audio amplifier module 120 is connected to the reverse diaphragm of the dual crystal microphone 111, while the signal output terminal of the second audio amplifier circuit 122 is connected to the input terminal of the second audio output circuit 132. At the same time, the output terminal of the second audio output circuit 132 is connected to the output terminal 133, thereby forming a second cardioid directional signal circuit as the second audio output channel.

[0033] The second audio output circuit 132 is configured to form two signal output ports at its output end, and is simultaneously connected to the output terminal 133.

[0034] In the second cardioid directional signal circuit formed here, the second audio amplifier circuit 122 receives the second audio signal output from the reverse diaphragm of the dual crystal microphone 111, amplifies it, and outputs it to the second audio output circuit 132. The second audio output circuit 132 processes the received second audio signal to form two second cardioid directional audio signals for output.

[0035] As further explained, the second-stage audio amplifier circuit 122 is specifically configured to convert the single-ended (reverse) high-impedance signal of the microphone into a low-impedance balanced differential signal and output two signals. The two differential signals after conversion are of the same frequency, equal amplitude and have a phase difference of 180 degrees.

[0036] Correspondingly, the second audio output circuit 132 is configured to perform 0dB voltage gain processing on the input signal. Simultaneously, the second audio output circuit 132 is also configured for low impedance output and enhanced load capacity. After processing the two differential signals generated by the second-stage audio amplifier circuit 122, the second audio output circuit 132 can output to the subsequent MIX stage.

[0037] Based on the four output signals mentioned above, the directional properties can be conveniently adjusted at the MIX level according to the user's directional requirements or during later music production. This solves the problem in existing solutions where the directional properties cannot be changed later if they are not suitable for the live performance.

[0038] As can be seen from the above, in this pickup circuit 100, the audio amplification module 120 and the audio output module 130 cooperate to form a first cardioid directional signal circuit and a second cardioid directional signal circuit in parallel, which are connected in parallel to the dual crystal microphone 111 in the audio input module 110. They can simultaneously process the two audio signals output by the dual crystal microphone 111, generating two sets of four-channel output signals. These two sets of four-channel signals can be input to the back-end tuning equipment and arbitrarily combined to form the desired directional signal, such as circular, figure-eight, cardioid, etc.

[0039] The following is a further explanation of the pickup circuit 100 scheme provided by this utility model through specific implementation methods.

[0040] The pickup circuit 100 in this invention can be directly applied to a microphone to form a corresponding pickup component.

[0041] See Figure 2 The diagram shows a specific implementation example of the pickup circuit 100 provided by this utility model in application.

[0042] Based on the diagram, in the specific implementation of this pickup circuit 100, the audio input module is mainly composed of a dual crystal microphone, high impedance R6, and high impedance R19.

[0043] The audio amplification module is mainly composed of high-impedance resistors R7 and R18, FET transistors T2 and T4, and resistors R2, R10, R11, R12, R14, R21, R22, and R23.

[0044] The corresponding audio output module is mainly composed of resistors R1, R3, R4, R5, R8, R9, R13, R15, R16, R17, R20, and R21, capacitors C3, C4, C5, C6, C10, C11, C12, and C13, transistors T1A, T1B, T3A, and T3B, inductors L1 and L2, and output terminal XLR1.

[0045] As further explanation, in the specific configuration of this pickup circuit, the middle plate 1 of the dual crystal microphone head is connected to a polarization voltage, which is a fixed value.

[0046] In the dual-crystal microphone, the positive diaphragm (Pin0) is connected to one end of high-resistance resistor R6, and the other end of high-resistance resistor R6 is connected to ground. The positive diaphragm (Pin0) is also connected to one end of coupling capacitor C2, and the other end of coupling capacitor C2 is connected to the gate of FET T2. The gate of T2 is also connected to one end of high-resistance resistor R7, and the other end of high-resistance resistor R7 is connected to one end of resistor R12, the other end of resistor R12 is grounded, and the other end of high-resistance resistor R7 is also connected to one end of resistor R10, the other end of resistor R10 is connected to the source of T2, and the source of T2 is connected to one end of resistor R11, the other end of which is grounded. The source of T2 is also connected to one end of capacitor C7, the other end of C7 is connected to the base of transistor T1A, the base of T1A is connected to one end of resistors R5 and R8 respectively, the other end of R5 is connected to the collector of T1A, and the other end of R8 is connected to the emitter of T1A. The emitter of T1A is connected to... One end of resistor R9 is connected to the other end of inductor L1, which is connected to capacitor C4. The other end of C4 is grounded. The third pin of L1 is also connected to capacitor C6 and grounded. The third pin of L1 is connected to the third pin of output terminal XLR1 to output a negative signal. The drain of T2 is connected to power supply VCC through resistor R2. The drain of T2 is also connected to the base of transistor T1B through capacitor C1. The base of T1B is connected to one end of resistors R1 and R4 respectively. The other end of R4 is connected to the collector of T1B. The collector of T1B is also connected to the collector of T1A. The other end of R1 is connected to the emitter of T1B. The emitter of T1B is connected to one end of resistor R3. The other end of R3 is connected to the first pin of L1. The first pin of L1 is connected to capacitor C3. The other end of C3 is grounded. The second pin of L1 is also connected to capacitor C5 and grounded. The second and third pins of L1 are connected to the second pin of output terminal XLR1 to output a positive signal.

[0047] In the dual-channel microphone, the reverse diaphragm (Pin2) is connected to one end of high-resistance resistor R19, the other end of which is connected to ground. The reverse diaphragm (Pin2) is also connected to one end of coupling capacitor C9, the other end of which is connected to the gate of FET T4. The gate of T4 is also connected to one end of high-resistance resistor R18, the other end of which is connected to one end of resistor R24, the other end of which is grounded. The other end of high-resistance resistor R18 is also connected to one end of resistor R22, the other end of which is connected to the source of T4. The source of T4 is connected to one end of resistor R23, the other end of which is grounded. The source of T4 is also connected to one end of capacitor C14; the other end of C14 is connected to the base of transistor T3A. The base of T3A is connected to one end of resistors R17 and R20, the other end of which is connected to the collector of T3A, and the other end of R20 is connected to the emitter of T3A. The emitter of T3A is connected to resistor R21. One end of R21 is connected to pin 4 of inductor L2. Pin 4 of inductor L2 is connected to capacitor C11, and the other end of C11 is grounded. Pin 3 of L2 is also connected to capacitor C13 to ground. Pin 3 of L2 is connected to pin 5 of output terminal XLR1 to output a negative signal. The drain of T4 is connected to power supply VCC through resistor R14. The drain of T4 is also connected to the base of transistor T3B through capacitor C8. The base of T3B is connected to one end of resistors R13 and R16 respectively. The other end of R16 is connected to the collector of T3B. The collector of T3B is also connected to the collector of T3A. The other end of R13 is connected to the emitter of T3B. The emitter of T3B is connected to one end of resistor R15. The other end of R15 is connected to pin 1 of L2. Pin 1 of L2 is connected to capacitor C10, and the other end of C10 is grounded. Pin 2 of L2 is also connected to capacitor C12 to ground. Pin 2 of L2 is connected to pin 4 of output terminal XLR1 to output a positive signal.

[0048] The resulting pickup circuit uses a dual-crystal microphone to pick up audio signals, outputting two audio signals (i.e., two single-ended high-impedance microphone signals) from the front and back of the microphone. These two signals are processed by two parallel amplifier circuits, each signal being converted into two low-impedance balanced differential signals with the same frequency, equal amplitude, and a phase difference of 180 degrees. The four signals generated by the two parallel amplifier circuits are simultaneously output to two parallel output circuit modules, resulting in two sets of four signals: channel 1 (2+, 3-) picked up from the front of the microphone and channel 2 (4+, 5-) picked up from the back.

[0049] The two sets of four signals generated by this pickup circuit can be directly output to the back-end mixing equipment via the output terminals. In the back-end mixing equipment, these four signals can be arbitrarily combined to form the desired directional signal, such as circular, figure-eight, or cardioid, making the application more convenient and flexible. The signal synthesis scheme will not be elaborated here; it can be determined according to actual needs.

[0050] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A sound pickup circuit, comprising an audio input module, an audio amplification module, and an audio output module, characterized in that, The audio input module includes a dual-crystal microphone head and a polarization voltage circuit. The polarization voltage circuit is configured to connect to the middle electrode plate of the dual-crystal microphone head and provide a fixed polarization voltage to the dual-crystal microphone head. The audio amplification module includes a first audio amplification circuit and a second audio amplification circuit; the audio output module includes a first audio output circuit, a second audio output circuit, and an output terminal; The signal input terminal of the first audio amplifier circuit is connected to the positive diaphragm of the dual crystal microphone, the signal output terminal of the first audio amplifier circuit is connected to the input terminal of the first audio output circuit, and the output terminal of the first audio output circuit is connected to the output terminal to form the first audio output channel. The signal input terminal of the second audio amplifier circuit is connected to the inverting diaphragm of the dual crystal microphone, the signal output terminal of the second audio amplifier circuit is connected to the input terminal of the second audio output circuit, and the output terminal of the second audio output circuit is connected to the output terminal to form the second audio output channel.

2. The pickup circuit according to claim 1, characterized in that, The first audio output channel and the second audio output channel can form two sets of four-channel signal outputs.

3. The pickup circuit according to claim 1, characterized in that, The first audio output channel and the second audio output channel simultaneously output cardioid directional signals.

4. The pickup circuit according to claim 1, characterized in that, The audio input module is also equipped with an impedance transformation element.

5. The pickup circuit according to claim 1, characterized in that, The first audio amplifier circuit and / or the second audio amplifier circuit are mainly based on field-effect transistors.

6. A microphone, characterized in that, The microphone is equipped with the pickup circuit according to any one of claims 1-5.

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