A preamplifier module circuit for a sound console

Abstract

The application relates to the technical field of amplification control and the like, and provides a preamplifier module circuit of a mixing console, wherein an input processing circuit of the module circuit buffers and amplifies an electric guitar signal to obtain a standard-level electric guitar signal, the standard-level electric guitar signal is output to a limiting circuit of the module circuit for processing, a fidelity electric guitar signal is obtained, the fidelity electric guitar signal is input to an audio effect adjusting circuit of the module circuit for adjusting, a preliminary mixing electric guitar signal is obtained, the preliminary mixing electric guitar signal is input to an attenuation circuit of the module circuit for processing, an effecter input signal is obtained, the effecter input signal is transmitted to an external effecter for processing to generate a to-be-mixed electric guitar signal, an AUX interface audio signal processing circuit of the module circuit processes an AUX interface audio signal after the AUX interface audio signal is input, to obtain a to-be-mixed audio signal, a mixing signal output processing circuit of the module circuit processes the to-be-mixed audio signal and the to-be-mixed electric guitar signal, to obtain a mixing signal suitable for earphone playing and used for output, so that the audio of different signal sources can work seamlessly and coordinately, and the audio output quality is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical fields of electronic circuit manufacturing, electronic device manufacturing, amplification control, and electro-acoustic musical instruments, and particularly relates to a preamplifier module circuit of a mixing console. BACKGROUND

[0002] The preamplifier module of a mixing console is a key component in mixing console technology, which can be used for gain amplification, sound effect adjustment, signal mixing, and final output of electric guitar signals. The preamplifier circuit of a mixing console needs to meet multiple requirements, including high fidelity, low noise, adaptation to different signal source levels, flexible sound effect adjustment, etc. However, in the prior art, the preamplifier module of a mixing console has some significant technical defects when implementing these functions. For example, in traditional mixing console designs, the signal levels from different audio sources (such as electric guitar and AUX input) differ greatly, leading to problems during signal mixing. Electric guitar signals are usually weak and low in level, requiring high gain amplification; while AUX interface audio signals are usually from external audio devices and have higher levels. Due to the lack of sufficient gain adjustment and level matching means, these two signals may have inconsistent levels during mixing, resulting in some signals being too strong, some signals being too weak, and even distortion or signal loss problems during audio output. For example, the signal processing circuit of the preamplifier module of a mixing console may not have fully considered the isolation between signal sources. Especially different audio sources from AUX input and electric guitar signals may interfere with each other without effective isolation, leading to signal crosstalk and increased noise. This crosstalk phenomenon not only affects audio quality, but also may cause audio distortion, reducing the signal-to-noise ratio of the system. For another example, AUX interface audio signals are usually from different audio devices such as audio players, external effects, etc. Since the signal levels and impedance characteristics of these devices are different from electric guitar signals, the mixing console lacks effective circuits to properly amplify, gain adjust, and impedance match AUX interface audio signals. As a result, AUX interface audio signals may not work in coordination with electric guitar signals, leading to problems such as volume imbalance, reduced audio quality, etc. during mixing. For another example, electric guitar signals usually need to be processed through effects, with distortion, reverb, delay, etc. sound effects; while AUX interface audio signals usually come from external devices without processing or with less sound effects. In traditional mixing consoles, the mixing and adjustment of audio effects may not be consistent across different signal sources, especially when processing AUX interface audio signals and electric guitar signals simultaneously. This inconsistency in audio effect processing may result in unnatural effects during audio mixing, lacking in level and spatial sense.

[0003] In summary, the existing mixer preamplifier module technology generally has problems such as unmatched levels, insufficient signal isolation, noise interference and the like when facing electric guitar signals and AUX interface audio signals. In addition, the adaptation and processing of AUX interface audio signals, the unified adjustment of sound effects and the like are often not effectively solved. SUMMARY

[0004] The present application provides a mixer preamplifier module circuit, which aims to ensure that audio from different signal sources can work seamlessly by means of precise signal gain adjustment, signal isolation, mixing processing and the like, to improve the quality of audio output, and to ensure that high-quality audio processing and mixing effects can be achieved in the case of different sound sources.

[0005] The present application provides a mixer preamplifier module circuit, comprising:

[0006] An electric guitar signal input processing circuit is used to buffer the electric guitar signal and amplify the buffered electric guitar signal to obtain a standard level electric guitar signal output with increased level;

[0007] A limiting circuit is electrically connected to the output end of the electric guitar signal input processing circuit, used to receive the standard level electric guitar signal and perform level limiting processing to obtain a fidelity electric guitar signal output with a level not exceeding a first threshold range;

[0008] An audio effect adjustment circuit is electrically connected to the output end of the limiting circuit, used to receive the fidelity electric guitar signal and perform audio effect adjustment to obtain a preliminary mixing electric guitar signal output suitable for mixing processing;

[0009] An attenuation circuit is electrically connected to the output end of the audio effect adjustment circuit, used to receive the preliminary mixing electric guitar signal and perform level attenuation processing to obtain an effecter input signal with a level not exceeding a second threshold range transmitted to an external effecter, which further adjusts the audio effect of the effecter input signal to obtain a to-be-mixed electric guitar signal output suitable for mixing processing;

[0010] An AUX interface audio signal processing circuit is used to amplify the AUX interface audio signal to obtain a to-be-mixed audio signal output with a level matched with the to-be-mixed electric guitar signal;

[0011] A mixing signal output processing circuit is electrically connected to the output end of the external effecter and the AUX interface audio signal processing circuit, used to receive the to-be-mixed audio signal and the to-be-mixed electric guitar signal and perform mixing gain adjustment to obtain a mixing signal with appropriate volume, and perform headphone amplifier processing on the mixing signal with appropriate volume to obtain a mixing signal suitable for headphone playback for output to the headphone.

[0012] Compared with the prior art, the present application has the following advantages:

[0013] The present application provides a kind of front amplifier module circuit of mixing console, by setting electric guitar signal input processing circuit, limiting circuit, sound effect adjustment circuit, attenuation circuit, AUX interface audio signal processing circuit and mix signal output processing circuit, electric guitar signal input processing circuit is used to access electric guitar signal and carry out buffering processing, and the gain amplification of electric guitar signal after buffering is carried out, to obtain the standard level electric guitar signal output after the increase of electric level, limiting circuit is electrically connected with the output end of the electric guitar signal input processing circuit, for receiving the standard level electric guitar signal and carrying out level limiting processing, to obtain the fidelity electric guitar signal output that level does not exceed the first threshold range, sound effect adjustment circuit is electrically connected with the output end of the limiting circuit, for receiving the fidelity electric guitar signal and carrying out sound effect adjustment, to obtain the preliminary mix electric guitar signal output that adapts mix processing, attenuation circuit is electrically connected with the output end of the sound effect adjustment circuit, for receiving the preliminary mix electric guitar signal and carrying out level attenuation processing, to obtain the effecter input signal transmission to external effecter that level does not exceed the second threshold range, the external effecter carries out further sound effect adjustment to the effecter input signal to obtain the to-be-mixed electric guitar signal output that adapts mix processing, AUX interface audio signal processing circuit is used to access AUX interface audio signal and carry out amplification processing, to obtain the to-be-mixed audio signal output that level is matched with the to-be-mixed electric guitar signal, mix signal output processing circuit is electrically connected with the output end of the external effecter and the AUX interface audio signal processing circuit, for receiving the to-be-mixed audio signal and the to-be-mixed electric guitar signal and carrying out mix gain adjustment, to obtain the mix signal of moderate volume, and the headphone amplifier processing of the mix signal of moderate volume is carried out, to obtain the mix signal suitable for headphone playback for output to earphone, so that the audio of different signal sources can work seamlessly, the audio output quality is improved, and high-quality audio processing and mix effect are realized in the case of different sound sources. BRIEF DESCRIPTION OF DRAWINGS

[0014] The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings, which are not necessarily drawn to scale, like reference numerals describe similar components throughout the several views. The specific embodiments of the present application will now be described with reference to the drawings.

[0015] Fig. 1This is a circuit structure diagram of a preamplifier module circuit of a mixing console according to an embodiment of the present invention;

[0016] Fig. 2 This is a schematic diagram of a circuit structure in which a preamplifier module circuit of a mixing console according to an embodiment of the present invention is connected to an external effector;

[0017] Fig. 3 The present invention is a schematic diagram of a circuit structure in which a preamplifier module circuit of a mixing console is connected to headphones.

[0018] Description of reference numerals:

[0019] 100, electric guitar signal input processing circuit; 200, limiting circuit; 300, sound effect adjustment circuit; 400, attenuation circuit; 500, AUX interface audio signal processing circuit; 600, mixing signal output processing circuit; 700, external effector; 800, headphones. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0021] See also Figs. 1-3 , an embodiment of the present invention provides a preamplifier module circuit of a mixing console, comprising:

[0022] An electric guitar signal input processing circuit is used to receive an electric guitar signal for buffering and amplify the buffered electric guitar signal to obtain a standard-level electric guitar signal output after the level is increased;

[0023] a limiting circuit electrically connected to the output terminal of the electric guitar signal input processing circuit, configured to receive the standard-level electric guitar signal and perform level limiting processing thereon to obtain a fidelity electric guitar signal output whose level does not exceed a first threshold range;

[0024] a sound effect adjustment circuit electrically connected to the output end of the limiting circuit, for receiving the fidelity electric guitar signal and performing sound effect adjustment to obtain a preliminary mixed electric guitar signal output adapted for mixing processing;

[0025] an attenuation circuit electrically connected to the output end of the sound effect adjustment circuit, configured to receive the preliminary mixed electric guitar signal and then perform level attenuation processing to obtain an effector input signal whose level does not exceed a second threshold range, and transmit the signal to the external effector, wherein the external effector further performs sound effect adjustment on the effector input signal to obtain an electric guitar signal to be mixed that is adapted for the mixing processing;

[0026] An AUX interface audio signal processing circuit is used to receive the AUX interface audio signal and then amplify it to obtain an audio signal to be mixed whose level matches that of the electric guitar signal to be mixed;

[0027] The mixed signal output processing circuit is electrically connected to the output end of the external effector and the AUX interface audio signal processing circuit, and is used to receive the audio signal to be mixed and the electric guitar signal to be mixed, and then adjust the mixing gain to obtain a mixed signal with a moderate volume. The mixed signal with a moderate volume is then processed by a headphone amplifier to obtain a mixed signal suitable for headphone playback for output to the headphone.

[0028] It should be noted that electric guitar signals typically have a low level and require buffering and gain amplification. In this embodiment, after the electric guitar signal passes through the electric guitar signal input processing circuit for buffering and gain amplification, the signal level is increased to a standard level range, facilitating subsequent processing by the limiting circuit. The limiting circuit limits the maximum level of the standard-level electric guitar signal to prevent distortion caused by excessive signal strength. The limiting circuit sets a first threshold range. Any standard-level electric guitar signal exceeding this threshold range is compressed or limited, resulting in a fidelity electric guitar signal output. This ensures that the output signal's dynamic range is within an appropriate range, ensuring clarity and fidelity of the sound quality. The sound effect adjustment circuit performs sound effect processing and frequency response adjustment on the fidelity electric guitar signal. By adjusting sound effects (such as high-frequency enhancement and low-frequency attenuation), the fidelity electric guitar signal is adapted to the mixing requirements, ensuring the sound quality of the fidelity electric guitar signal is adjusted to better meet the overall sound effect requirements of the mixing console, thereby producing a preliminary mixed electric guitar signal. The preliminary mixed electric guitar signal output from the sound effect adjustment circuit is attenuated by the attenuation circuit. The attenuation circuit reduces the level of the pre-mixed electric guitar signal to a level suitable for feeding into an external effects processor, preventing distortion caused by excessively strong input signals. The attenuation circuit adjusts the level of the pre-mixed electric guitar signal to an appropriate range, ensuring that subsequent processing by the external effects processor does not cause distortion or degrade the sound quality. The attenuated pre-mixed electric guitar signal is then output to the external effects processor for further audio processing (such as distortion, reverberation, and delay). The external effects processor then adjusts the attenuated pre-mixed electric guitar signal to produce a pre-mixed electric guitar signal suitable for mixing with other audio signals. The AUX interface audio signal processing circuit receives the AUX interface audio signal, which is the signal from an external audio device (such as an audio player). The AUX interface audio signal is typically at a higher level and requires gain amplification to match it with the pre-mixed electric guitar signal, resulting in the pre-mixed audio signal. The gain adjustment of the AUX interface audio signal produces the pre-mixed audio signal. The levels of the pre-mixed audio signal and the pre-mixed electric guitar signal are then aligned, ensuring coordinated operation in the subsequent mixed signal output processing circuit. The audio signal to be mixed and the electric guitar signal to be mixed enter the mixed signal output processing circuit together. The mixed signal output processing circuit adjusts the mixing gain of the audio signal to be mixed and the electric guitar signal to be mixed to ensure that the volume of the mixed signal is moderate, thereby obtaining a mixed signal with moderate volume. Finally, the mixed signal with moderate volume is processed by the headphone amplifier to obtain a mixed signal suitable for headphone playback for output to the headphones, ensuring that the final volume is suitable for headphone playback and maintaining undistorted sound quality. It should be noted that in this embodiment, the first threshold range can be set to the maximum safe level of the signal before entering the subsequent processing stage. This range is used to avoid distortion caused by excessive input signals. For the electric guitar signal input processing circuit, this threshold range can be designed according to the signal source and the required sound quality.For example, if a standard electric guitar signal operates between 0.1V and 1V, the first threshold range could be set to 0.5V to 1.5V. This ensures the signal remains clear and prevents overload from exceeding the maximum safe level. The second threshold range can be used to limit the input signal to an effects processor, ensuring that the signal level passed to an external effects processor is neither too high nor too low, which could affect subsequent effects processing. The second threshold range can be set to accommodate the maximum input level of the external effects processor and the mixing process. For example, if the ideal input signal range for an effects processor is -10dB to +4dB, the second threshold range could be set to this range to ensure that the signal is neither too high, causing excessive distortion, nor too low, preventing the processor from performing at its full potential. In summary, the first threshold range primarily ensures that the signal entering the electric guitar input processing circuitry is not too high, thereby avoiding damage or distortion; while the second threshold range primarily ensures that the signal passed to the external effects processor is suitable for further effects processing, ensuring optimal performance.

[0029] In some preferred embodiments, the electric guitar signal input processing circuit comprises an input buffer circuit and a gain amplification circuit, the output end of the input buffer circuit and the input end of the gain amplification circuit are electrically connected; after the input end of the input buffer circuit is connected to the electric guitar signal, the input buffer circuit buffers the connected electric guitar signal to obtain a buffered electric guitar signal output to the gain amplification circuit, and the gain amplification circuit amplifies the buffered electric guitar signal to obtain a standard level electric guitar signal with increased level output. It should be noted that the electric guitar signal is usually connected to the audio mixer preamplifier module circuit through the input end from an external device (such as an electric guitar). Since the electric guitar signal is usually low in level (weak signal), directly entering the subsequent circuit may be disturbed, distorted or attenuated. Therefore, the input buffer circuit plays a very important role. After the input end of the input buffer circuit is connected to the electric guitar signal, the input buffer circuit can buffer the connected electric guitar signal. The input buffer circuit can adopt a high input impedance circuit structure, which will not burden the electric guitar signal and will not consume the energy of the signal, ensuring the integrity of the signal source. After buffering, the electric guitar signal maintains its integrity and is not affected by the input impedance, thereby ensuring the quality and stability of the signal. After the buffered electric guitar signal passes through the gain amplification circuit, through appropriate gain setting, the gain amplification circuit can amplify the electric guitar signal to a standard level range suitable for subsequent processing and mixing. This gain amplification process not only ensures that the level of the electric guitar signal reaches the ideal range, but also ensures that the signal can be transmitted to the subsequent circuit (such as the limiting circuit, the sound effect adjustment circuit, etc.) without signal loss or insufficient situation. The gain amplification circuit increases the signal to the standard level output, so that the subsequent circuit can process the signal losslessly and clearly. Through reasonable gain setting, distortion and interference in the subsequent audio processing stage can be avoided. In this embodiment, through the design of the input buffer and gain amplification two stages, the adaptability of the audio mixer preamplifier module to different signal sources can be enhanced, so that the circuit can automatically adjust the signal level and ensure the stability of the signal when facing different types of signal sources (such as electric guitar, AUX input, etc.), greatly improving the flexibility and stability of the audio mixer.

[0030] In some preferred embodiments, the input buffer circuit includes an operational amplifier U1. After the electric guitar signal is connected to its input, the operational amplifier U1 buffers the input signal to generate a buffered electric guitar signal, which is then output to the gain amplifier circuit. It should be noted that the high input impedance of operational amplifier U1 effectively prevents impedance loading from the electric guitar signal source, thereby ensuring the integrity of the signal source output. This means that the signal source does not experience significant signal attenuation or distortion due to the buffer circuit, maintaining a pure and undamaged signal. This is particularly important for electric guitar signals, which are typically weak. Direct connection to subsequent circuits can easily lead to signal attenuation and compromise sound quality. The high input impedance of operational amplifier U1 enables it to receive signals from the electric guitar signal source without significantly loading it. This allows the electric guitar signal source to continue functioning normally under low loads.

[0031] In some preferred embodiments, the gain amplifier circuit includes an operational amplifier U2 and a variable resistor VR1. The input of the operational amplifier U2 and the input of the variable resistor VR1 are commonly connected to receive the buffered electric guitar signal. The output of the operational amplifier U2 and the output of the variable resistor VR1 are commonly connected to output the standard-level electric guitar signal. The variable resistance adjustment terminal of the variable resistor VR1 is grounded. The operational amplifier U2 and the variable resistor VR1 jointly perform gain amplification on the buffered electric guitar signal to produce a standard-level electric guitar signal with an amplified level. It should be noted that after the buffered electric guitar signal is output from the operational amplifier U1, it enters the gain amplifier circuit as the input signal. Specifically, the buffered signal is input to the input of the operational amplifier U2 and also to the input of the variable resistor VR1. The variable resistor VR1 is an adjustable resistor whose resistance value can be adjusted to control the gain. The adjustment terminal of the variable resistor VR1 is grounded. Changing its resistance value affects the gain of the operational amplifier U2, thereby affecting the gain amplification of the output signal. The adjustable terminal of rheostat VR1 is used to adjust the gain, allowing the user to set the desired gain value, thereby achieving precise gain amplification of the electric guitar signal. Operational amplifier U2 is used to amplify the signal gain. After receiving the buffered electric guitar signal, op amp U2, combined with the adjustment of rheostat VR1, amplifies the input signal to an appropriate level. The gain of op amp U2 is determined by the resistance value of rheostat VR1. Adjusting the rheostat effectively changes the feedback circuit of the op amp, thereby adjusting the gain. Due to the high gain accuracy and stability of the op amp, the output signal is amplified to the required standard level without distortion. The amplified signal is output through the output of op amp U2 and the output of rheostat VR1. At this point, the output signal has reached the required standard level and is suitable for subsequent circuit processing. The output signal level is precisely controlled, ensuring that the signal will not be distorted or difficult to process due to excessively high or low levels during subsequent processing.

[0032] In some preferred embodiments, the limiting circuit includes an operational amplifier U3, the input of which is connected to the output of operational amplifier U2 and the output of variable resistor VR1, for receiving the standard-level electric guitar signal. Operational amplifier U3 performs level limiting processing on the received standard-level electric guitar signal to produce a fidelity electric guitar signal output whose level does not exceed a first threshold range. It should be noted that the electric guitar signal has already been amplified by the aforementioned gain amplifier circuit, resulting in a standard-level electric guitar signal that enters the input of operational amplifier U3. Operational amplifier U3 limits the signal level to ensure that the signal does not exceed a predetermined first threshold range. Once the signal level exceeds the first threshold range, operational amplifier U3 clamps the signal level within this threshold range to prevent distortion or saturation caused by excessively high signal levels. For audio signals, excessively high signal levels may cause amplifier distortion or overload of subsequent equipment, affecting the final sound quality. After the limiting processing by operational amplifier U3, the output is a fidelity electric guitar signal whose level does not exceed the first threshold range. This signal will not exceed the set maximum level, so its sound quality is more stable and clear, and will not be distorted due to excessive level.

[0033] In some preferred embodiments, the sound effect adjustment circuit includes an equalizer (EQ). The input of the equalizer (EQ) is connected to the output of the operational amplifier (U3) for receiving the fidelity electric guitar signal. The equalizer (EQ) performs sound effect adjustment on the received fidelity electric guitar signal to produce a preliminary mixed electric guitar signal suitable for mixing processing. It should be noted that the electric guitar signal undergoes gain amplification, limiting, and other processing to produce a fidelity electric guitar signal. This signal has already been level-limited by the operational amplifier (U3) to ensure its level is within a safe range. The fidelity electric guitar signal is transmitted to the equalizer (EQ), serving as the input signal for the equalizer (EQ). An equalizer (EQ) is a circuit capable of adjusting the gain of signals in different frequency bands. It typically has multiple frequency bands and can add or subtract gain to signals in different frequency bands, such as low, mid, and high frequencies, to adjust the timbre or sound effects. In this embodiment, the equalizer (EQ) performs sound effect adjustment on the received fidelity electric guitar signal. This process can include bass enhancement, high frequency reduction, and mid-frequency correction. By adjusting the gain of different frequency bands, the signal's timbre, dynamics, and spatial perception are altered. After sound adjustments, the output is a pre-mixed electric guitar signal suitable for mixing. This means the signal's sound quality has been optimized for your needs, making it suitable for further mixing and processing. As you can see, using the EQ, you can fine-tune the sound of the electric guitar signal to your needs, such as adding bass weight, adjusting the midrange to emphasize certain tones, or removing unwanted frequencies. Using the EQ, the electric guitar signal can be adapted to different musical styles or performance requirements, providing flexible sound control.

[0034] Further, when the equalizer EQ adjusts the sound effect of the received fidelity electric guitar signal, it includes: independently adjusting different frequency bands of the received fidelity electric guitar signal through multiple filter bands (such as low frequency, medium frequency and high frequency) in the equalizer EQ, specifically: increasing the low frequency response of the low frequency band fidelity electric guitar signal (such as 20Hz-150Hz) to enhance the thickness of the electric guitar tone; strengthening the mid-frequency response of the mid-frequency band fidelity electric guitar signal (such as 150Hz-2kHz) to make the tone of the guitar more clear and prominent; adjusting the high frequency part of the high frequency band fidelity electric guitar signal (such as 2kHz-10kHz) to enhance the clarity, brightness or sharpness of the guitar; and dynamically adjusting the gain of the different frequency bands of the independently adjusted fidelity electric guitar signal to obtain a preliminary mixed electric guitar signal output suitable for mixing. It should be noted that low frequency is a very important part of electric guitar tone, especially in heavy rock, blues and other styles, low frequency can provide the thickness and depth of the tone. The low frequency component in the electric guitar signal affects the fullness and foundation of the tone. By increasing the low frequency response, the sound of the electric guitar can better coordinate with the bass guitar or drum in the mixing, so that the tone has a sense of hierarchy and richer sound performance. The mid-frequency is a key frequency band of the electric guitar tone, which affects the clarity and expressiveness of the notes. The characteristic tone of the electric guitar is usually in the mid-frequency region, especially below 2kHz. By increasing the mid-frequency band, the performance of the guitar notes can be more vivid and clear, especially when playing techniques such as slides, bends, etc., the fine and dynamic sense of the tone can be enhanced. High frequency affects the brightness, clarity and sharpness of the tone. Proper high frequency enhancement can make the electric guitar tone appear brighter, more transparent and delicate. High frequency is very important when playing fast notes, percussive effects or playing clear single notes. By increasing the high frequency part, the guitar can appear brighter and more delicate in the mix, especially the high frequency part can enhance the attack and presence of the notes. Dynamic gain adjustment is the management of signal amplitude changes over time, ensuring that each frequency band is adjusted dynamically according to the actual strength of the signal without distortion and avoiding overload. Dynamic gain control can optimize different frequency bands according to actual conditions, avoiding excessive enhancement or attenuation of any frequency band. It can provide smoother audio performance and avoid distortion caused by excessive gain. Through this dynamic adjustment, the balance and consistency of the entire audio signal can be guaranteed, while avoiding volume imbalance between different frequency bands.

[0035] In some preferred embodiments, the attenuation circuit includes an operational amplifier U4, the input terminal of which is connected with the output terminal of the equalizer EQ, for receiving the preliminary mixed electric guitar signal; the operational amplifier U4 performs a level attenuation processing on the received preliminary mixed electric guitar signal, to obtain an effecter input signal with a level not exceeding a second threshold range, which is transmitted to an external effecter. It should be noted that in the foregoing circuit, the electric guitar signal has been processed by gain amplification, limiting circuit and sound effect adjustment, etc. In particular, during the sound effect adjustment stage, the signal passes through the equalizer EQ and is output as a preliminary mixed electric guitar signal after sound effect adjustment. This preliminary mixed electric guitar signal is input to the input terminal of the operational amplifier U4 as the object of attenuation processing. The operational amplifier U4 attenuates the level of the signal and reduces the amplitude of the signal through gain adjustment, so that the signal level does not exceed the set second threshold range. This level range can ensure that the signal entering the external effecter will not exceed the input processing capacity of the effecter, thereby avoiding distortion or clipping phenomenon caused by excessive signal strength. The attenuated signal will be transmitted to the input terminal of the external effecter. The effecter can further process the signal according to the set sound effect parameters to generate a mixed electric guitar signal suitable for mixing. It should be noted that in the entire circuit, the first threshold range mentioned above refers to the level of the electric guitar signal being limited to a value not exceeding a certain range after the signal is processed by the limiting circuit (i.e. operational amplifier U3), to ensure that the signal does not appear to be too strong, overloaded or distorted. This processing can ensure the quality and stability of the signal. Within the first threshold range, the signal has been limited by the operational amplifier U3 to avoid excessive signal strength and maintain its fidelity. The role of the attenuation circuit (U4) is to further attenuate the level of the signal to ensure that the level of the signal does not exceed the input requirements of the external effecter before being sent to the external effecter, or to avoid distortion and other problems. Therefore, the first threshold range can limit the maximum level of the signal to ensure signal stability, and the signal is adjusted by the second threshold range to ensure that the signal can adapt to the input requirements of the external effecter, avoiding the risk of mismatch between the two. The first threshold range limiting processing before the attenuation circuit and the second threshold range attenuation after the attenuation circuit can achieve the level balance between the electric guitar signal and other input signals (such as AUX interface audio signals), to ensure the volume coordination of different signal sources during mixing.

[0036] In some preferred embodiments, the output of the operational amplifier U4 is connected to the input of the external effects processor via the FX SEND socket, transmitting the effects processor input signal to the external effects processor for processing. The output of the external effects processor is connected to the input of the mixed signal output processing circuit via the FX RETURN socket, transmitting the electric guitar signal to be mixed to the mixed signal output processing circuit for processing. It should be noted that the signal processed by the attenuation circuit (operational amplifier U4), i.e., the effects processor input signal, is output via the FX SEND socket and transmitted to the input of the external effects processor. The external effects processor performs further audio effects processing (such as delay, reverb, distortion, etc.) on the input electric guitar signal to generate the electric guitar signal to be mixed. The processed signal from the external effects processor is returned to the preamplifier module of the mixing console via the FX RETURN socket. This signal is then connected to the mixed signal output processing circuit via the FX RETURN socket, initiating the subsequent mixing process.

[0037] Furthermore, after the effects input signal, whose level does not exceed the second threshold range, is input to the external effects processor, the external effects processor applies a delay effect to the signal to simulate the reflections of a guitar. It also adds spatial processing to the signal after the delay effect to enhance the guitar's reverberation. It also applies overdrive to the signal after the spatial processing to enhance the guitar's timbre and expressiveness. It should be noted that an equalizer (EQ) primarily modulates the timbre of an electric guitar signal by adjusting different frequency bands (such as low, mid, and high frequencies) to achieve a preliminary sound suitable for mixing. EQ can enhance or cut certain frequencies to change the weight, clarity, or brightness of a guitar's sound. However, EQ only adjusts at the frequency level and has limited impact on the signal's spatiality, dynamics, and expressiveness. An equalizer cannot directly add spatiality, delay, or reverberation to a signal, nor can it simulate the dynamics of a guitar during actual performance (such as overdrive). An external effects processor, however, can perform dynamic and spatial processing, providing a more nuanced and richer performance. Delay effects simulate the reflections of a guitar, causing notes to reverberate after being played, enhancing the depth and spatiality of the sound. Spatial processing (such as reverb) adds an ambient feel to the signal, giving the guitar sound a more three-dimensional and layered quality, and enhancing its live performance. Overdrive enhances the guitar's tonal expressiveness, simulating the drive of an amplifier to create a bolder, more powerful, or aggressive sound. These effects are beyond the reach of EQ, and in practice, they can add greater expressiveness, spatiality, and emotional expression to electric guitar signals. While EQing an electric guitar signal optimizes and balances the frequency spectrum, it still lacks expressiveness, spatiality, dynamics, and emotional expression. External effects processors, such as delay and reverb, can further enhance the layering, spatiality, and expressiveness of the sound, making the guitar sound richer, more engaging, and more expressive.

[0038] In some preferred embodiments, the AUX interface audio signal processing circuit comprises an operational amplifier U5; after the input end of the operational amplifier U5 is connected to the AUX interface audio signal, the operational amplifier U5 amplifies the AUX interface audio signal to obtain an audio signal to be mixed, the level of which is matched with the electric guitar signal to be mixed; the output end of the operational amplifier U5 is connected to the mixed signal output processing circuit, and the audio signal to be mixed is output to the mixed signal output processing circuit for processing. It should be noted that the audio signal input through the AUX interface usually comes from external devices such as audio players and the like. The output level of these devices is usually high, but different from the level of the electric guitar signal, and thus needs to be processed to match with other signals (such as the electric guitar signal). The operational amplifier U5 amplifies the input AUX interface audio signal. Specifically, the operational amplifier U5 adjusts the level of the AUX interface audio signal to a range matched with the electric guitar signal through gain adjustment. Since the level of the AUX interface audio signal is usually high, the operational amplifier U5 converts it into an audio signal to be mixed matched with the electric guitar signal through appropriate gain or attenuation, ensuring that the signal levels are consistent during mixing. The amplified audio signal to be mixed is transmitted to the mixed signal output processing circuit through the output end of the operational amplifier U5. This signal will enter the mixing stage together with the processed electric guitar signal for gain adjustment and sound effect processing, and finally form a mixed signal suitable for headphone playback.

[0039] In some preferred embodiments, the mixed sound signal output processing circuit includes a mixed sound gain adjustment circuit and a headphone amplifier processing circuit; the input end of the mixed sound gain adjustment circuit is electrically connected with the output end of the external effecter and the output end of the AUX interface audio signal processing circuit, the output end of the mixed sound gain adjustment circuit is electrically connected with the input end of the headphone amplifier processing circuit, and the output end of the headphone amplifier processing circuit outputs the mixed sound signal suitable for headphone playing; the mixed sound gain adjustment circuit adjusts the mixed sound gain of the received audio signal to be mixed and the electric guitar signal to be mixed to obtain a mixed sound signal with appropriate volume output to the headphone amplifier processing circuit, and the headphone amplifier processing circuit processes the mixed sound signal with appropriate volume to obtain the mixed sound signal suitable for headphone playing. It should be noted that the input end of the mixed sound gain adjustment circuit receives signals from the output end of the external effecter and the output end of the AUX interface audio signal processing circuit. These signals include processed electric guitar signals (i.e. audio signals to be mixed) and amplified AUX interface audio signals (i.e. audio signals to be mixed), which come from different audio sources (electric guitar and AUX interface device). After receiving audio signals from two different signal sources, the mixed sound gain adjustment circuit adjusts the mixed sound gain. The main purpose is to adjust the signal strength of each audio source according to the user's volume balance setting, so as to obtain a mixed sound signal with appropriate volume. This process ensures that the audio signals from the electric guitar and the AUX interface can achieve the ideal volume balance after mixing, avoiding the problem of too large or too small volume. The adjusted mixed sound signal is further amplified by the headphone amplifier processing circuit to adapt to the standard volume of headphone playing. The headphone amplifier processing circuit further amplifies the mixed sound signal to ensure that the headphone can receive sufficient audio signal strength to achieve the ideal volume level. The audio signal after headphone amplifier processing is output to the headphone socket, and the user can listen to the mixed audio content through the headphone. This processing method can ensure that the audio output by the headphone is clear and has appropriate volume.

[0040] In further some preferred embodiments, the sound mixing gain adjustment circuit comprises an operational amplifier U6 and a variable resistor VR6; the input end of the operational amplifier U6 is the input end of the sound mixing gain adjustment circuit, and is electrically connected with the output end of the external effects device and the output end of the AUX interface audio signal processing circuit; the output end of the operational amplifier U6 is connected with the input end of the variable resistor VR6, the ground end of the variable resistor VR6 is grounded, and the variable resistance adjustment end of the variable resistor VR6 is electrically connected with the input end of the headphone amplifier processing circuit; the operational amplifier U6 and the variable resistor VR6 jointly perform sound mixing gain adjustment on the received sound mixing audio signal and the sound mixing electric guitar signal to obtain the sound volume appropriate sound mixing signal, and the variable resistance adjustment end of the variable resistor VR6 outputs the sound volume appropriate sound mixing signal to the headphone amplifier processing circuit for headphone amplifier processing. It should be noted that the input end of the sound mixing gain adjustment circuit receives signals from two different signal sources: one from the output end of the external effects device, and the other from the output end of the AUX interface audio signal processing circuit. These signals are processed in advance and are respectively the sound mixing electric guitar signal and the sound mixing AUX interface audio signal. After receiving the two signals, the operational amplifier U6 mixes and adjusts the gain of the signals. As the core element of gain adjustment and signal mixing, the gain value of the operational amplifier is adjusted according to the intensity of the input signal. The variable resistor VR6 further adjusts the gain of the sound mixing signal. The variable resistor has three ports: the ground end of the variable resistor is connected to the ground; the input end of the variable resistor is connected with the output end of the operational amplifier U6 for receiving the mixed signal of the operational amplifier; and the adjustment end (i.e. the variable resistance adjustment end) of the variable resistor is connected to the input end of the headphone amplifier processing circuit to output the adjusted sound volume appropriate signal to the headphone amplifier for further amplification. The adjustment end of the variable resistor is the part for adjusting the volume, which can finely adjust the gain of the signal to obtain the sound volume appropriate sound mixing signal. The adjusted sound volume appropriate sound mixing signal is output to the headphone amplifier processing circuit through the variable resistor VR6, and after further amplification by the headphone amplifier, the signal is output to the headphone. This process can ensure that the signal played through the headphone can meet the volume requirement and maintain good sound quality. It can be understood that in this embodiment, the operational amplifier U6 and the variable resistor VR6 work together to ensure that the mixed signal can achieve the ideal volume balance. The variable resistor VR6 allows accurate adjustment of the volume according to actual needs, so that the final output sound mixing signal has the effect of sound volume appropriate. Through the adjustment end of the variable resistor, the volume can be adjusted according to the needs during use, avoiding excessively high or low volume output, and ensuring the comfort of audio monitoring. The variable resistor VR6 provides the function of adjustable gain, which supports adjusting the volume of the mixed signal in real time according to the strength of the input signal and the needs of the sound effect. Unlike simple fixed gain adjustment, the adjustable nature of the variable resistor provides more flexibility, making the tuning process more refined and personalized.The coordinated operation of op amp U6 and variable resistor VR6 balances the signal strengths from the different sources (electric guitar and AUX jack). Since these signals typically have different levels, proper gain adjustment ensures that they are balanced in the final mix, preventing signals from being too strong or too weak. The gain adjustment and signal mixing capabilities of op amp U6 ensure that the signals remain clear and high-fidelity during the mix. With refined mixing gain adjustment, the final audio signal is free of distortion, audible clicks, or noise.

[0041] In some further preferred embodiments, the headphone amplifier processing circuit includes: operational amplifiers U7 and U8; the inputs of operational amplifiers U7 and U8 are connected to the variable resistance adjustment terminal of variable resistor VR6, and the outputs of operational amplifiers U7 and U8 output the mixed audio signal suitable for headphone playback; operational amplifiers U7 and U8 receive the moderately loud mixed audio signal output by the variable resistance adjustment terminal of variable resistor VR6 and amplify the received moderately loud mixed audio signal to generate the mixed audio signal suitable for headphone playback. The mixed audio signal suitable for headphone playback can be connected to headphones via the headphone jack HEADPHONES. It should be noted that the inputs of operational amplifiers U7 and U8 receive the signal from the variable resistance adjustment terminal of variable resistor VR6. This signal is the moderately loud mixed audio signal after preliminary mixing gain adjustment, representing the final audio output signal, which has been mixed and gain-adjusted from different audio sources (e.g., an electric guitar signal and an AUX interface audio signal). Operational amplifiers U7 and U8 further amplify this moderately loud mixed audio signal. Headphones typically require a higher audio level to ensure adequate output volume. Therefore, operational amplifiers U7 and U8 adjust the amplification factor based on the input signal strength to ensure the signal is within a level range suitable for headphone playback. The amplified signal is output through the output terminals of operational amplifiers U7 and U8 and can be connected to the headphone jack, HEADPHONES. This signal is a mixed signal suitable for headphone playback and can directly drive the headphones for audio output.

[0042] It should be noted that the above embodiments are only the preferred specific embodiments of the present application, not the limitation thereof, the protection scope of the present application is not limited thereto, the above embodiments or the technical features among different embodiments can also be combined, and there are many other changes of different aspects of the present application as described above, which can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application. Any change or replacement that can be easily thought of by those skilled in the art within the technical range disclosed by the present application should be covered within the protection scope of the present application, and the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A preamplifier module circuit for a mixing console, characterized in that: include: An electric guitar signal input processing circuit is used to receive an electric guitar signal for buffering and amplify the buffered electric guitar signal to obtain a standard-level electric guitar signal output after the level is increased; a limiting circuit electrically connected to the output terminal of the electric guitar signal input processing circuit, configured to receive the standard-level electric guitar signal and perform level limiting processing thereon to obtain a fidelity electric guitar signal output whose level does not exceed a first threshold range; a sound effect adjustment circuit electrically connected to the output end of the limiting circuit, for receiving the fidelity electric guitar signal and performing sound effect adjustment to obtain a preliminary mixed electric guitar signal output adapted for mixing processing; an attenuation circuit electrically connected to the output end of the sound effect adjustment circuit, configured to receive the preliminary mixed electric guitar signal and then perform level attenuation processing to obtain an effector input signal whose level does not exceed a second threshold range, and transmit the signal to the external effector, wherein the external effector further performs sound effect adjustment on the effector input signal to obtain an electric guitar signal to be mixed that is adapted for the mixing processing; An AUX interface audio signal processing circuit is used to receive the AUX interface audio signal and then amplify it to obtain an audio signal to be mixed whose level matches that of the electric guitar signal to be mixed; a mixed signal output processing circuit, electrically connected to the output terminal of the external effector and the AUX interface audio signal processing circuit, configured to receive the audio signal to be mixed and the electric guitar signal to be mixed, perform mixing gain adjustment to obtain a mixed signal with a moderate volume, and perform headphone amplifier processing on the mixed signal with a moderate volume to obtain a mixed signal suitable for headphone playback for output to the headphone; The mixed signal output processing circuit includes a mixing gain adjustment circuit and a headphone amplifier processing circuit; the input end of the mixing gain adjustment circuit is electrically connected to the output end of the external effector and the output end of the AUX interface audio signal processing circuit, the output end of the mixing gain adjustment circuit is electrically connected to the input end of the headphone amplifier processing circuit, and the output end of the headphone amplifier processing circuit outputs the mixed signal suitable for headphone playback; the mixing gain adjustment circuit adjusts the mixing gain of the received audio signal to be mixed and the received electric guitar signal to be mixed to obtain a mixed signal with a moderate volume, which is output to the headphone amplifier processing circuit. The headphone amplifier processing circuit performs headphone amplifier processing on the mixed signal with a moderate volume to obtain the mixed signal suitable for headphone playback; The mixing gain adjustment circuit includes an operational amplifier U6 and a variable resistor VR6; the input end of the operational amplifier U6 is the input end of the mixing gain adjustment circuit, and is electrically connected to the output end of the external effector and the output end of the AUX interface audio signal processing circuit. The output end of the operational amplifier U6 is connected to the input end of the variable resistor VR6, the ground end of the variable resistor VR6 is grounded, and the variable resistance adjustment end of the variable resistor VR6 is electrically connected to the input end of the headphone amplifier processing circuit; the operational amplifier U6 and the variable resistor VR6 jointly adjust the mixing gain of the received audio signal to be mixed and the electric guitar signal to be mixed to obtain the mixed signal with moderate volume, and the variable resistance adjustment end of the variable resistor VR6 outputs the mixed signal with moderate volume to the headphone amplifier processing circuit for headphone amplifier processing.

2. The preamplifier module circuit of the mixing console as claimed in claim 1, characterized in that: The electric guitar signal input processing circuit includes an input buffer circuit and a gain amplifier circuit. The output end of the input buffer circuit is electrically connected to the input end of the gain amplifier circuit. After the input end of the input buffer circuit receives the electric guitar signal, the input buffer circuit buffers the received electric guitar signal to obtain a buffered electric guitar signal, which is output to the gain amplifier circuit. The gain amplifier circuit then performs gain amplification on the buffered electric guitar signal to obtain a standard-level electric guitar signal with an increased level.

3. The preamplifier module circuit of the mixing console as claimed in claim 2, characterized in that: The input buffer circuit includes an operational amplifier U1. After the input end of the operational amplifier U1 is connected to the electric guitar signal, the operational amplifier U1 buffers the connected electric guitar signal to obtain a buffered electric guitar signal and outputs it to the gain amplifier circuit.

4. The preamplifier module circuit of the mixing console as claimed in claim 3, characterized in that: The gain amplifier circuit includes an operational amplifier U2 and a variable resistor VR1; the input end of the operational amplifier U2 and the input end of the variable resistor VR1 are commonly connected to receive the buffered electric guitar signal; the output end of the operational amplifier U2 and the output end of the variable resistor VR1 are commonly connected to output the standard-level electric guitar signal; the variable resistance adjustment end of the variable resistor VR1 is grounded; the operational amplifier U2 and the variable resistor VR1 jointly perform gain amplification processing on the buffered electric guitar signal to obtain a standard-level electric guitar signal with an increased level.

5. The preamplifier module circuit of the mixing console as claimed in claim 4, characterized in that: The limiting circuit includes an operational amplifier U3, the input end of which is connected to the output end of the operational amplifier U2 and the output end of the variable resistor VR1, and is configured to receive the standard-level electric guitar signal. The operational amplifier U3 performs level limiting processing on the received standard-level electric guitar signal to output a fidelity electric guitar signal whose level does not exceed a first threshold range.

6. The preamplifier module circuit of the mixing console as claimed in claim 5, characterized in that: The sound effect adjustment circuit includes an equalizer EQ; the input end of the equalizer EQ is connected to the output end of the operational amplifier U3, and is used to receive the fidelity electric guitar signal; the equalizer EQ performs sound effect adjustment on the received fidelity electric guitar signal to obtain a preliminary mixed electric guitar signal output that is adapted for mixing processing.

7. The preamplifier module circuit of the mixing console as claimed in claim 6, characterized in that: The attenuation circuit includes an operational amplifier U4, the input end of which is connected to the output end of the equalizer EQ, for receiving the preliminary mixed electric guitar signal; the operational amplifier U4 performs level attenuation processing on the received preliminary mixed electric guitar signal to obtain an effector input signal with a level not exceeding a second threshold range, which is transmitted to the external effector.

8. The preamplifier module circuit of the mixing console as claimed in claim 7, characterized in that: The output end of the operational amplifier U4 is connected to the input end of the external effector through the socket FX SEND to transmit the effector input signal to the external effector for processing; the output end of the external effector is connected to the input end of the mixing signal output processing circuit through the socket FX RETURN to transmit the electric guitar signal to be mixed to the mixing signal output processing circuit for processing.

9. The preamplifier module circuit of the mixing console as claimed in claim 8, characterized in that: The AUX interface audio signal processing circuit includes an operational amplifier U5; after the input end of the operational amplifier U5 is connected to the AUX interface audio signal, the operational amplifier U5 amplifies the AUX interface audio signal to obtain an audio signal to be mixed whose level matches the electric guitar signal to be mixed; the output end of the operational amplifier U5 is connected to the mixed signal output processing circuit, and outputs the audio signal to be mixed to the mixed signal output processing circuit for processing.

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