CN219536282U - Sound circuit - Google Patents
Sound circuit Download PDFInfo
- Publication number
- CN219536282U CN219536282U CN202221255862.5U CN202221255862U CN219536282U CN 219536282 U CN219536282 U CN 219536282U CN 202221255862 U CN202221255862 U CN 202221255862U CN 219536282 U CN219536282 U CN 219536282U
- Authority
- CN
- China
- Prior art keywords
- terminal
- coupled
- transistor
- capacitor
- field effect
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
Landscapes
- Amplifiers (AREA)
Abstract
The utility model provides an acoustic circuit, comprising: a pre-amplification circuit configured to amplify the sound source signal; a power amplifying circuit coupled to the pre-amplifying circuit to secondarily amplify the sound source signal; a speaker coupled to the power amplification circuit to convert the secondarily amplified sound source signal into a sound signal output; the amplifying circuit comprises a primary amplifying circuit, a secondary amplifying circuit and a tertiary amplifying circuit which are sequentially and directly coupled; the first-stage amplifying circuit comprises a junction field effect transistor, the second-stage amplifying circuit comprises an electron tube, and the third-stage amplifying circuit comprises a transistor, wherein the junction field effect transistor, the electron tube and the transistor are directly coupled; a feedback circuit is coupled between the junction field effect transistor and the transistor. The advantages are that: the technical indexes such as signal to noise ratio, analytic force, distortion, frequency response, driving force and the like and subjective hearing are all more than Ma Lanshi 7.
Description
Technical Field
The utility model belongs to the technical field of circuits, and particularly relates to an acoustic circuit.
Background
In the sound system, the audio pre-amplifier amplifies the input signal of the sound source and outputs the amplified signal to the audio power amplifier, and the audio power amplifier amplifies the input signal of the audio pre-amplifier to generate enough output power to drive the loudspeaker system to play sound. In the case of the advanced audio preamplifier, the technical index is not a problem, and the actual hearing is emphasized, so that the amplifier is generally not formed by an integrated circuit with good test index and general hearing, and is a circuit of a split device or a circuit of an electronic tube more commonly.
As shown in fig. 6, a well-known Ma Lanshi seven (maratz 7) front stage is constituted by a valve circuit. The music has the characteristics of rich musical flavor, large dynamic range and good hearing. However, the Ma Lanshi seven circuit has the following disadvantages:
1. a large amount of coupling capacitance is used, so that serious phase shift is caused, and a large phase difference exists between two channels easily.
2. The circuit is a three-stage electron tube amplifying circuit, the first-stage amplifying circuit adopts an electron tube to supply power to a filament, extra interference exists, the noise of the electron tube is generally larger than BJT and FET, the signal-to-noise ratio is reduced, and the small signal analysis force is insufficient; meanwhile, in order to ensure linearity, the power supply voltage of the electronic tube cannot be too low, so that direct coupling with a second-stage amplifying circuit is difficult, RC coupling is forced to be adopted, and distortion and phase shift are increased.
Disclosure of Invention
The present utility model aims to solve the above problems and provide an acoustic circuit with small phase shift, low noise and low distortion.
An acoustic circuit comprising:
an input node configured to receive a sound source signal;
an output node configured to output a first electrical signal;
a pre-amplification circuit coupled between the input node and the output node to amplify a sound source signal to form a first electrical signal;
a power amplification circuit coupled to the output node to amplify the first electrical signal to form a second electrical signal;
a speaker coupled to the power amplification circuit to convert the second electrical signal to a sound signal output;
the pre-stage amplifying circuit comprises a first-stage amplifying circuit, a second-stage amplifying circuit and a third-stage amplifying circuit, wherein the first-stage amplifying circuit is coupled between the input node and the second-stage amplifying circuit, the second-stage amplifying circuit is coupled to the third-stage amplifying circuit, and the third-stage amplifying circuit is coupled to the output node;
the first-stage amplifying circuit comprises a junction field effect transistor, the second-stage amplifying circuit comprises an electron tube, the third-stage amplifying circuit comprises a transistor, the transistor is a bipolar junction transistor or a MOS transistor, a first terminal of the junction field effect transistor is coupled to the input node, a second terminal of the junction field effect transistor is directly coupled to the first terminal of the electron tube, a second terminal of the electron tube is directly coupled to the first terminal of the transistor, and a third terminal of the transistor is coupled to the output node; a feedback circuit is coupled between the third terminal of the junction field effect transistor and the third terminal of the transistor.
The first-stage amplifying circuit replaces a Ma Lanshi seventh electron tube with a junction field effect tube:
1. the noise is low, and the low current linearity is good;
2. the power supply voltage is far lower than the electron tube, so that the direct coupling with the secondary amplifying circuit is facilitated, and the distortion of capacitive coupling is eliminated;
3. the filament is not needed to supply power;
4. as with the valve, no coupling capacitor is needed between the valve and the input node;
5. the disadvantage of having a dynamic range lower than that of the valve is negligible here, because it is at the first stage;
6. the characteristics of the junction field effect transistor are very similar to those of the electron tube, and the hearing aspect is almost the same, but the expressive force on music details is obviously better than that of most electron tubes.
The two-stage amplifying circuit keeps the same valve amplifying circuit as Ma Lanshi seven to keep the advantages of wide dynamic range and good linearity.
The three-stage amplifying circuit replaces a Ma Lanshi seventh electronic tube with a bipolar junction transistor or a MOS tube, has poor linearity, works in an emitter/cathode follower state, has high input impedance, low output impedance, good linearity, low distortion, small phase shift, wide frequency response, rapid following, strong driving force and convenient tube selection, can be directly coupled with the two-stage amplifying circuit, and is an excellent follower.
Preferably, a first capacitor is coupled between the third terminal of the transistor and the output node, one end of the first capacitor coupled to the output node being further coupled to a ground terminal through an eighth resistor.
Preferably, the second terminal of the junction field effect transistor is further coupled to a first supply voltage source, and the third terminal of the junction field effect transistor is coupled to a ground terminal; a third terminal of the valve is coupled to a ground terminal; the first and second terminals of the transistor are coupled to each other, the second terminal of the transistor is coupled to a second supply voltage source, and the third terminal of the transistor is coupled to a ground terminal.
Preferably, the junction field effect transistor is an N-channel junction field effect transistor, a first terminal thereof is a gate terminal, a second terminal thereof is a drain terminal, and a third terminal thereof is a source terminal; the electron tube is a triode or adopts a triode connection method of a tetrode or adopts a triode connection method of a pentadiode, a first terminal is a grid terminal, a second terminal is an anode terminal, and a third terminal is a cathode terminal; the bipolar junction transistor is an NPN bipolar junction transistor, a first terminal of the transistor is a base terminal of the NPN bipolar junction transistor or a gate terminal of the MOS transistor, a second terminal of the transistor is a collector terminal of the NPN bipolar junction transistor or a drain terminal of the MOS transistor, a third terminal of the transistor is an emitter terminal of the NPN bipolar junction transistor or a source terminal of the MOS transistor,
preferably, the second terminal of the junction field effect transistor is coupled to the first supply voltage source through a second resistor, the third terminal of the junction field effect transistor is coupled to a ground terminal through a third resistor, the first terminal of the transistor is coupled to the second terminal of the transistor through a fifth resistor, the third terminal of the valve is coupled to the ground terminal through a sixth resistor, and the third terminal of the transistor is coupled to the ground terminal through a seventh resistor. Because the voltage of the first supply voltage source is far lower than that of the second supply voltage source, the resistance value of the second resistor is far smaller than that of the corresponding resistor 270K of Yu Malan Shiqi, the negative feedback of the stage is larger than Ma Lanshi seven, the gain of the stage is also lower than Ma Lanshi seven, and the junction field effect transistor in the primary amplifying circuit and the electron tube in the secondary amplifying circuit are directly coupled, so that the working states of the first amplifying circuit and the second amplifying circuit are better than Ma Lanshi seven.
Preferably, a volume adjustment circuit is coupled between the input node and the first terminal of the junction field effect transistor. The volume can be controlled by setting a volume adjusting circuit.
Preferably, the volume adjustment circuit includes a first resistor coupled between the input node and a first terminal of the junction field effect transistor, the first terminal of the junction field effect transistor being coupled to a ground terminal through a varistor.
Preferably, the feedback circuit comprises a fourth resistor and a third capacitor connected in parallel with each other, the third capacitor is a COG capacitance or an NP0 capacitance or a mica capacitance, one end of the fourth resistor and the third capacitor connected in parallel is coupled to a third terminal of the junction field effect transistor, the other end of the fourth resistor and the third capacitor connected in parallel is coupled to a movable end of a single pole double throw switch, one of the fixed ends of the single pole double throw switch is coupled to a third terminal of the transistor through a second capacitor, and the other fixed end of the single pole double throw switch is coupled to the output node. The third capacitor is a COG capacitor or an NP0 capacitor or a mica capacitor with small influence on tone quality and tone quality, so when the single-pole double-throw switch is connected to the fixed end of the output node, the feedback channel has no capacitance and no influence on the tone quality of the whole machine, and at the moment, the forward channel has only one capacitance of the first capacitor from the perspective of the whole audio channel, so that tone quality can be conveniently adjusted only by selecting the first capacitors with different materials and brands; when a single pole double throw switch is connected to the stationary terminal coupled to the third terminal of the transistor through the second capacitor, the tone color is changed due to the connection of the second capacitor, thereby enabling the tone color to be changed while the tone color can be corrected by changing the second capacitor.
Preferably, the feedback circuit includes a fourth resistor and a third capacitor connected in parallel with each other, the third capacitor being COG capacitance or NP0 capacitance or mica capacitance, one end of the fourth resistor and the third capacitor connected in parallel being coupled to the third terminal of the junction field effect transistor, the other end of the fourth resistor and the third capacitor connected in parallel being coupled to the third terminal of the transistor through a second capacitor.
Preferably, the feedback circuit includes a fourth resistor and a third capacitor connected in parallel with each other, the third capacitor being COG capacitance or NP0 capacitance or mica capacitance, one end of the fourth resistor and the third capacitor connected in parallel being coupled to the third terminal of the junction field effect transistor, the other end of the fourth resistor and the third capacitor connected in parallel being coupled to the output node.
Compared with the prior art, the sound circuit has the advantages that:
1. the first-stage amplifying circuit replaces a Ma Lanshi seventh electron tube with a junction field effect tube: the noise is low, and the low current linearity is good; the power supply voltage is far lower than the electron tube, so that the direct coupling with the secondary amplifying circuit is facilitated, and the distortion of capacitive coupling is eliminated; the filament is not needed to supply power; as with the valve, no coupling capacitor is needed between the valve and the input node; the disadvantage of having a dynamic range lower than that of the valve is negligible here, because it is at the first stage; the characteristics of the junction field effect transistor are very similar to those of the electron tube, the hearing aspect is almost the same, but the expressive force on music details is obviously better than that of most electron tubes;
2. the two-stage amplifying circuit keeps the same valve amplifying circuit as Ma Lanshi seven so as to keep the advantages of wide dynamic range and good linearity;
3. the three-stage amplifying circuit replaces a Ma Lanshi seventh electronic tube with a bipolar junction transistor or a MOS tube, has poor linearity, works in an emitter/cathode follower state, has high input impedance, low output impedance, good linearity, low distortion, small phase shift, wide frequency response, rapid following, strong driving force and convenient tube selection, can be directly coupled with the two-stage amplifying circuit, and is an excellent follower;
4. because the voltage of the first supply voltage source is far lower than that of the second supply voltage source, the resistance value of the second resistor is far smaller than that of a corresponding resistor 270K of Yu Malan Shiqi, the negative feedback of the stage is larger than Ma Lanshi seven, the gain of the stage is also lower than Ma Lanshi seven, and the junction field effect transistor in the primary amplifying circuit and the electron tube in the secondary amplifying circuit are directly coupled, so that the working states of the first amplifying circuit and the second amplifying circuit are better than Ma Lanshi seven;
5. the volume can be controlled by setting a volume adjusting circuit;
6. the third capacitor is a COG capacitor or an NP0 capacitor or a mica capacitor with small influence on tone quality and tone quality, so when the single-pole double-throw switch is connected to the fixed end of the output node, the feedback channel has no capacitance and no influence on the tone quality of the whole machine, and at the moment, the forward channel has only one capacitance of the first capacitor from the perspective of the whole audio channel, so that tone quality can be conveniently adjusted only by selecting the first capacitors with different materials and brands; when a single pole double throw switch is connected to the stationary terminal coupled to the third terminal of the transistor through the second capacitor, the tone color is changed due to the connection of the second capacitor, thereby enabling the tone color to be changed while the tone color can be corrected by changing the second capacitor.
Drawings
Fig. 1 provides a front-end amplification circuit diagram of a first embodiment of the present utility model.
Fig. 2 provides a circuit block diagram of a first embodiment of the present utility model.
Fig. 3 provides a front-end amplification circuit diagram of a second embodiment of the present utility model.
Fig. 4 provides a front-end amplification circuit diagram of a third embodiment of the present utility model.
Fig. 5 provides a front-end amplification circuit diagram of a fourth embodiment of the present utility model.
Fig. 6 provides a circuit diagram of a prior art Ma Lanshi seventh audio preamplifier.
In the figure, an input node 1, an output node 2, a front stage amplifying circuit 3, a primary amplifying circuit 31, a secondary amplifying circuit 32, a tertiary amplifying circuit 33, a volume adjusting circuit 4, a feedback circuit 5, a power amplifying circuit 6, a speaker 7, a single pole double throw switch S1, a junction field effect transistor T1, a valve T2, a transistor T3, a first capacitor C1, a second capacitor C2, a third capacitor C3, a varistor R0, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a first supply voltage source V1, and a second supply voltage source V2.
Detailed Description
The following disclosure sets forth various exemplary embodiments to achieve different features of the subject matter. Specific examples of components and arrangements are set forth below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, it will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or one or more intervening elements may be present.
Example 1
As shown in fig. 1-2, an audio circuit includes:
an input node 1 configured to receive a sound source signal;
an output node 2 configured to output a first electrical signal;
a pre-amplification circuit 3 coupled between the input node 1 and the output node 2 to amplify the sound source signal to form a first electrical signal;
a power amplifying circuit 6 coupled to the output node 2 for amplifying the first electrical signal to form a second electrical signal, the power amplifying circuit 6 being optionally a circuit of the prior art, which is not an innovation of the present utility model, so that a specific circuit structure is not described;
a speaker 7 coupled to the power amplification circuit 6 to convert the second electric signal into an acoustic signal output;
the pre-stage amplifying circuit 3 comprises a first-stage amplifying circuit 31, a second-stage amplifying circuit 32, a third-stage amplifying circuit 33 and a feedback circuit 5, wherein the first-stage amplifying circuit 31 is coupled between the input node 1 and the second-stage amplifying circuit 32, the second-stage amplifying circuit 32 is coupled to the third-stage amplifying circuit 33, the third-stage amplifying circuit 33 is coupled to the output node 2, and the feedback circuit 5 is coupled between the first-stage amplifying circuit 31 and the feedback circuit 5;
the first-stage amplifying circuit 31 includes a junction field effect transistor T1, the second-stage amplifying circuit 32 includes a transistor T2, the third-stage amplifying circuit 33 includes a transistor T3, the transistor T3 is a bipolar junction transistor T3, a first terminal of the junction field effect transistor T1 is coupled to the input node 1, a second terminal of the junction field effect transistor T1 is directly coupled to a first terminal of the transistor T2, a second terminal of the transistor T2 is directly coupled to a first terminal of the transistor T3, and a third terminal of the transistor T3 is coupled to the output node 2.
The first-stage amplifying circuit 31 replaces the seventh valve T2 of Ma Lanshi with a junction field effect transistor T1:
1. the noise is low, and the low current linearity is good;
2. the supply voltage is far lower than the valve T2, so that the direct coupling with the secondary amplifying circuit 32 is facilitated, and the distortion of capacitive coupling is eliminated;
3. the filament is not needed to supply power;
4. as with valve T2, no coupling capacitance is required between it and input node 1;
5. the disadvantage of having a dynamic range lower than that of the valve T2 is negligible here, because it is at the first stage;
6. the characteristics of the junction field effect transistor T1 are very similar to those of the electron tube T2, and the hearing aspect is almost the same, but the expressive force on music details is obviously better than that of most electron tubes T2.
The two-stage amplifying circuit 32 maintains the same valve T2 amplifying circuit as Ma Lanshi to retain the advantages of wide dynamic range and good linearity.
The three-stage amplifying circuit 33 replaces the seventh electronic tube T2 of Ma Lanshi with a bipolar junction transistor T3 or a MOS tube, has no poor linearity, works in an emitter/cathode follower state, has high input impedance, low output impedance, good linearity, low distortion, small phase shift, wide frequency response, rapid following, strong driving force and convenient tube selection, can be directly coupled with the two-stage amplifying circuit 32, and is a follower with excellent performance.
The second terminal of the junction field effect transistor T1 is coupled to the first supply voltage source V1 through the second resistor R2, the third terminal of the junction field effect transistor T1 is coupled to the ground terminal through the third resistor R3, the first terminal of the transistor T3 is coupled to the second terminal of the transistor T3 through the fifth resistor R5, the third terminal of the valve T2 is coupled to the ground terminal through the sixth resistor R6, and the third terminal of the transistor T3 is coupled to the ground terminal through the seventh resistor R7; the junction field effect transistor T1 is an N-channel junction field effect transistor T1, a first terminal is a gate terminal, a second terminal is a drain terminal, and a third terminal is a source terminal; the electron tube T2 is a triode or adopts a triode connection method of a tetrode or adopts a triode connection method of a penta-diode, a first terminal is a grid terminal, a second terminal is an anode terminal, and a third terminal is a cathode terminal; the bipolar junction transistor T3 is an NPN bipolar junction transistor T3, the first terminal of the transistor T3 is a base terminal of the NPN bipolar junction transistor T3, the second terminal of the transistor T3 is a collector terminal of the NPN bipolar junction transistor T3, and the third terminal of the transistor T3 is an emitter terminal of the NPN bipolar junction transistor T3.
Because the voltage of the first supply voltage source V1 is far lower than the voltage of the second supply voltage source V2, and is different by an order of magnitude, the resistance of the second resistor R2 is far smaller than the resistance of the corresponding resistor 270K of Yu Malan shiqi, and is different by an order of magnitude, the present-stage negative feedback of this stage is greater than Ma Lanshi V, the present-stage gain is also lower than Ma Lanshi V, and the junction field effect transistor T1 in the first-stage amplifying circuit 31 and the valve T2 in the second-stage amplifying circuit 32 are directly coupled, so that the operating states of the first-stage amplifying circuit 32 and the second-stage amplifying circuit 32 are better than Ma Lanshi V.
A volume adjustment circuit 4 is coupled between the input node 1 and the first terminal of the junction field effect transistor T1, the volume adjustment circuit 4 comprising a first resistor R1 coupled between the input node 1 and the first terminal of the junction field effect transistor T1, the first terminal of the junction field effect transistor T1 being coupled to the ground terminal through a varistor R0. The volume can be controlled by adjusting the resistance value of the varistor R0 in the volume adjusting circuit 4.
A first capacitor C1 is coupled between the third terminal of the transistor T3 and the output node 2, one end of the first capacitor C1 coupled to the output node 2 being further coupled to the ground terminal through an eighth resistor R8; a feedback circuit 5 is coupled between the third terminal of the junction field effect transistor T1 and the third terminal of the transistor T3, the feedback circuit 5 comprising a fourth resistor R4 and a third capacitor C3 connected in parallel with each other, one end of the fourth resistor R4 and the third capacitor C3 connected in parallel being coupled to the third terminal of the junction field effect transistor T1, the other end of the fourth resistor R4 and the third capacitor C3 connected in parallel being coupled to the movable end of the single pole double throw switch S1, one of the movable ends of the single pole double throw switch S1 being coupled to the third terminal of the transistor T3 through a second capacitor C2, the other one of the movable ends of the single pole double throw switch S1 being coupled to the output node 2.
Because the third capacitor C3 selects COG capacitance or NP0 capacitance or mica capacitance with small influence on tone quality and tone quality, when the single-pole double-throw switch S1 is connected to the fixed end coupled to the output node 2, the feedback channel has no capacitance and no influence on the tone quality of the whole machine, and at the moment, from the whole audio channel, the forward channel has only one capacitance of the first capacitor C1, so that tone quality can be conveniently adjusted only by selecting the first capacitors C1 with different materials and brands; when the single pole double throw switch S1 is connected to the stationary terminal coupled to the third terminal of the transistor T3 through the second capacitor C2, the tone color is changed due to the connection of the second capacitor C2, so that the tone color can be changed while the tone color can be corrected by replacing the second capacitor C2.
Example two
The structure, principle and implementation steps of this embodiment are similar to those of the embodiment, except that:
as shown in fig. 3, the transistor T3 is a MOS transistor, the first terminal thereof is a gate terminal of the MOS transistor, the second terminal thereof is a drain terminal of the MOS transistor, and the third terminal thereof is a source terminal of the MOS transistor.
Example III
The structure, principle and implementation steps of this embodiment are similar to those of the first or second embodiments, except that:
as shown in fig. 4, the feedback circuit 5 includes a fourth resistor R4 and a third capacitor C3 connected in parallel with each other, one end of the fourth resistor R4 and the third capacitor C3 connected in parallel is coupled to the third terminal of the junction field effect transistor T1, and the other end of the fourth resistor R4 and the third capacitor C3 connected in parallel is coupled to the output node 2. The third capacitor C3 is a COG capacitor or an NP0 capacitor or a mica capacitor with small influence on tone quality and tone quality, at the moment, the feedback channel has no capacitor, the whole tone quality is not influenced, and the forward channel has only one capacitor of the first capacitor C1 from the perspective of the whole audio channel, so that tone quality can be conveniently adjusted only by selecting the first capacitors C1 with different materials and brands.
Example IV
The structure, principle and implementation steps of this embodiment are similar to those of the first or second embodiments, except that:
as shown in fig. 5, the feedback circuit 5 includes a fourth resistor R4 and a third capacitor C3 connected in parallel to each other, one end of the fourth resistor R4 and the third capacitor C3 connected in parallel is coupled to the third terminal of the junction field effect transistor T1, and the other end of the fourth resistor R4 and the third capacitor C3 connected in parallel is coupled to the third terminal of the transistor T3 through the second capacitor C2. Because the second capacitor C2 is connected, the tone is controlled by the two capacitors, and the tone is more convenient to adjust.
The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present utility model. Those skilled in the art should appreciate that they may readily use the present utility model as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.
Claims (10)
1. An acoustic circuit comprising:
an input node configured to receive a sound source signal;
an output node configured to output a first electrical signal;
a pre-amplification circuit coupled between the input node and the output node to amplify a sound source signal to form a first electrical signal;
a power amplification circuit coupled to the output node to amplify the first electrical signal to form a second electrical signal;
a speaker coupled to the power amplification circuit to convert the second electrical signal to a sound signal output;
the front-stage amplifying circuit comprises a first-stage amplifying circuit, a second-stage amplifying circuit and a third-stage amplifying circuit, wherein the first-stage amplifying circuit is coupled between the input node and the second-stage amplifying circuit, the second-stage amplifying circuit is coupled to the third-stage amplifying circuit, and the third-stage amplifying circuit is coupled to the output node;
the first-stage amplifying circuit comprises a junction field effect transistor, the second-stage amplifying circuit comprises an electron tube, the third-stage amplifying circuit comprises a transistor, the transistor is a bipolar junction transistor or a MOS transistor, a first terminal of the junction field effect transistor is coupled to the input node, a second terminal of the junction field effect transistor is directly coupled to the first terminal of the electron tube, a second terminal of the electron tube is directly coupled to the first terminal of the transistor, and a third terminal of the transistor is coupled to the output node; a feedback circuit is coupled between the third terminal of the junction field effect transistor and the third terminal of the transistor.
2. An audio circuit as claimed in claim 1, characterized in that a first capacitor is coupled between the third terminal of the transistor and the output node, the end of the first capacitor coupled to the output node being further coupled to the ground terminal via an eighth resistor.
3. The audio circuit of claim 1, wherein the second terminal of the junction field effect transistor is further coupled to a first supply voltage source, and the third terminal of the junction field effect transistor is coupled to a ground terminal; a third terminal of the valve is coupled to a ground terminal; the first and second terminals of the transistor are coupled to each other, the second terminal of the transistor is coupled to a second supply voltage source, and the third terminal of the transistor is coupled to a ground terminal.
4. A sound circuit according to claim 3, wherein the junction field effect transistor is an N-channel junction field effect transistor, the first terminal of which is a gate terminal, the second terminal is a drain terminal, and the third terminal is a source terminal; the electron tube is a triode or adopts a triode connection method of a tetrode or adopts a triode connection method of a pentadiode, a first terminal is a grid terminal, a second terminal is an anode terminal, and a third terminal is a cathode terminal; the bipolar junction transistor is an NPN bipolar junction transistor, a first terminal of the transistor is a base terminal of the NPN bipolar junction transistor or a gate terminal of the MOS transistor, a second terminal of the transistor is a collector terminal of the NPN bipolar junction transistor or a drain terminal of the MOS transistor, and a third terminal of the transistor is an emitter terminal of the NPN bipolar junction transistor or a source terminal of the MOS transistor.
5. The audio circuit of claim 4, wherein the second terminal of the junction field effect transistor is coupled to the first supply voltage source through a second resistor, the third terminal of the junction field effect transistor is coupled to the ground terminal through a third resistor, the first terminal of the transistor is coupled to the second terminal of the transistor through a fifth resistor, the third terminal of the transistor is coupled to the ground terminal through a sixth resistor, and the third terminal of the transistor is coupled to the ground terminal through a seventh resistor.
6. An audio circuit according to any one of claims 2 to 5, wherein a volume adjustment circuit is coupled between the input node and the first terminal of the junction field effect transistor.
7. The audio circuit of claim 6, wherein the volume adjustment circuit comprises a first resistor coupled between the input node and a first terminal of the junction field effect transistor, the first terminal of the junction field effect transistor coupled to a ground terminal through a varistor.
8. An acoustic circuit according to any one of claims 2 to 5 wherein the feedback circuit comprises a fourth resistor and a third capacitor in parallel with each other, the third capacitor being either a COG capacitance or an NP0 capacitance or a mica capacitance, one end of the fourth resistor and the third capacitor in parallel being coupled to a third terminal of the junction field effect transistor, the other end of the fourth resistor and the third capacitor in parallel being coupled to a movable end of a single pole double throw switch, one of the stationary ends of the single pole double throw switch being coupled to a third terminal of the transistor through a second capacitor, the other stationary end of the single pole double throw switch being coupled to the output node.
9. An acoustic circuit according to any one of claims 2 to 5 wherein the feedback circuit comprises a fourth resistor and a third capacitor in parallel with each other, the third capacitor being either a COG capacitance or an NP0 capacitance or a mica capacitance, one end of the fourth resistor and the third capacitor in parallel being coupled to a third terminal of the junction field effect transistor, the other end of the fourth resistor and the third capacitor in parallel being coupled to a third terminal of the transistor through a second capacitor.
10. An acoustic circuit according to any one of claims 2 to 5 wherein the feedback circuit comprises a fourth resistor and a third capacitor in parallel with each other, the third capacitor being either a COG capacitance or an NP0 capacitance or a mica capacitance, one end of the fourth resistor and the third capacitor in parallel being coupled to a third terminal of the junction field effect transistor, the other end of the fourth resistor and the third capacitor in parallel being coupled to the output node.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221255862.5U CN219536282U (en) | 2022-05-24 | 2022-05-24 | Sound circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221255862.5U CN219536282U (en) | 2022-05-24 | 2022-05-24 | Sound circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN219536282U true CN219536282U (en) | 2023-08-15 |
Family
ID=87633061
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202221255862.5U Active CN219536282U (en) | 2022-05-24 | 2022-05-24 | Sound circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN219536282U (en) |
-
2022
- 2022-05-24 CN CN202221255862.5U patent/CN219536282U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1835390B (en) | Low noise amplifier | |
| WO2015139352A1 (en) | Current analog audio amplifier | |
| CN112260654B (en) | Power amplifier system | |
| CN101350605B (en) | Improved bipolar type variable gain amplifier with minimum gain control | |
| US7830210B2 (en) | Amplifier device | |
| CN219536282U (en) | Sound circuit | |
| CN201365228Y (en) | Pure post power amplifier with high fidelity, high linearity and broad frequency band | |
| JP2007184918A (en) | Balanced amplifier | |
| CN102025325B (en) | Audio frequency amplifier and its electronic equipment of use | |
| US2710312A (en) | Ultra linear amplifiers | |
| CN117155298A (en) | Audio pre-amplifier | |
| CN216390921U (en) | Power amplifier | |
| US5235288A (en) | Amplifier stage for low-resistance ac voltage sources | |
| JP2005506791A (en) | Power amplifier module | |
| CN209201020U (en) | A kind of integrated operational amplifier circuit for audio player | |
| CN217770324U (en) | Ear discharge circuit using discrete elements | |
| CN201341116Y (en) | High-precision current amplifier | |
| CN111082800A (en) | I/V converter | |
| CN116566338B (en) | Audio amplifying circuit | |
| CN220273644U (en) | Push-pull electron tube power amplifier circuit | |
| CN202261177U (en) | Transistor audio power amplifying circuit of low distortion transformer output | |
| CN214591944U (en) | Audio frequency amplitude limiting circuit of stereo set | |
| CN212785811U (en) | Startup and shutdown squelch circuit of cholelithiasis balance high-fidelity earphone amplifier | |
| CN218277129U (en) | Loudspeaker system | |
| CN112290899B (en) | Preamplifier of measuring circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |