JP4438818B2 - Circuit board group mounting structure for audio equipment - Google Patents

Description

  The present invention relates to a mounting structure in an audio device of a circuit board group composed of a plurality of circuit boards.

  2. Description of the Related Art Conventionally, home theater systems that provide a realistic sound field using a plurality of speakers, for example, are widely used in the home. In a home theater system, for example, an audio device called an AV amplifier that outputs audio signals to a plurality of speakers is used (see, for example, Patent Document 1).

JP 2006-129147 A

  When this AV amplifier is used to construct a home theater system, for example, a DVD player, a television receiver, and a plurality of speakers are connected to the AV amplifier. For example, when this home theater system is a 7.1 channel specification, eight speakers corresponding to the number of channels are arranged.

  When a video signal and an audio signal are input from a DVD player, the AV amplifier processes the audio signal from the DVD player and outputs them to each speaker, and also processes the video signal from the DVD player and receives it as a television receiver. Output to the machine. An AV amplifier having a tuner mounted may be referred to as an “AV receiver”.

  FIG. 7 is an exploded perspective view showing an example of a conventional AV amplifier, as viewed from the back side of the AV amplifier. In FIG. 7, the upper panel covering from the upper part of the main body and the rear panel on the rear side of the main body are omitted. In the following, the lower right diagonal direction in FIG. 7 is the rear direction, the upper left diagonal direction in the drawing is the front direction, and the right side and the left side when viewing the AV amplifier from the rear direction.

  This AV amplifier has a main body 71 having a substantially rectangular parallelepiped shape. The main body 71 is mainly formed by combining a lower chassis 72, a front panel 73, a back panel (not shown), a pair of left and right side panels 75, and an upper panel (not shown). The lower chassis 72 includes a flat bottom plate portion 76 and a pair of side plate portions 77 extending in the orthogonal direction from the left and right ends of the bottom plate portion 76.

  Inside the main body 71, two heat sinks 78 disposed along the side plate portion 77 and an audio circuit board group 81 are provided. The audio circuit board group 81 includes an audio signal processing board 82 for mounting an electronic component such as a capacitor and a chip resistor and processing an audio signal, an amplifier circuit board 83 for amplifying the audio signal, and these boards 82 and 83. The power supply board 85 or the like for supplying a predetermined power supply voltage is used. Although not shown, a video signal processing board for processing a video signal, a power transformer, an exhaust fan, and the like are disposed inside the main body 71.

  According to FIG. 7, the audio signal processing board 82 is disposed along the bottom plate portion 76 of the lower chassis 72, and two heat sinks 78 are attached above the audio signal processing board 82 by a chassis (not shown). Two amplifier circuit boards 83 are respectively attached to the left and right side surfaces of each heat sink 78, and a total of four amplifier circuit boards 83 are arranged as a whole. The audio signal processing board 82 and the amplifier circuit board 83 are connected by a plurality of cables 90.

  Below each amplifier circuit board 83, a plurality of power transistors 84 are arranged so as to contact the heat sink 78. A power supply board 85 is attached to the back side of the heat sink 78 by a chassis (not shown).

  FIG. 8 is a diagram showing a block configuration of the audio circuit board group 81 described above. In the audio circuit board group 81, for example, audio signals for 7 channels are processed. The audio signal processing board 82 is constituted by a single board and includes a differential input circuit 86 and a pre-driver circuit 87. The differential input circuit 86 is a circuit for modulating an audio signal as an input signal, for example. The pre-driver circuit 87 is a circuit for amplifying the output signal of the differential input circuit 86.

  As shown in FIG. 7, the amplifier circuit board 83 is configured by a total of four boards, and each amplifier circuit board 83 is configured to process audio signals for two channels (excluding one board). Yes. The amplifier circuit board 83 includes a power transistor driver circuit 88 and an amplifier circuit 89 having a power transistor 85. The power transistor driver circuit 88 is a circuit for driving the power transistor 85. The amplifier circuit 89 is a circuit for amplifying the output signal of the power transistor driver circuit 88.

  Here, in the configuration of the conventional AV amplifier, a differential input circuit 86 and a pre-driver circuit 87 for seven channels are arranged on one audio signal processing board 82, and the power is divided into four amplifier circuit boards 83 to be used. A transistor driver circuit 88 and an amplifier circuit 89 are arranged. Then, one audio signal processing board 82 and four amplifier circuit boards 83 are connected by a plurality of cables 90, whereby a pre-driver circuit 87 and a power transistor driver circuit 88 are connected for each channel. Yes. In this way, the configuration in which the substrate is divided into a plurality of parts and the substrates are connected to each other is adopted because the main body 71 has a substantially rectangular parallelepiped shape of a predetermined size and needs to be stored compactly in this shape. For this reason, it is necessary to employ a configuration in which the divided substrates are three-dimensionally arranged and connected to each other.

  On the other hand, in audio equipment, it is generally required to shorten the signal line of an audio signal as much as possible. In other words, in audio equipment, input signals with relatively low voltage and current are amplified, but if the signal line through which the amplified high voltage or high current signal is transmitted becomes longer, other circuits (highly sensitive parts) This is because it is considered that the sound quality is deteriorated.

  However, in the structure of the conventional audio device, the audio signal processing board 82 and the amplifier circuit board 83 are connected by a plurality of relatively long cables 90. Therefore, the amplified signal of high voltage and current is amplified. Is transmitted via the cable 90, for example, the audio signal being processed in the audio signal processing board 82 may be adversely affected. That is, noise due to the cable 90 is mixed in the audio signal, and the audio signal mixed with noise is amplified as it is and output from each speaker, so that the sound quality of the output audio signal is deteriorated. That is, when the cable 90 is routed, the S / N ratio is deteriorated and the sound quality is deteriorated.

  The present invention has been conceived under the circumstances described above, and provides a circuit board group mounting structure in an audio device that can suppress the influence of an amplified audio signal on other circuits. This is the issue.

  In order to solve the above problems, the present invention takes the following technical means.

  A circuit board group mounting structure in an audio device provided by the present invention includes a signal input circuit for inputting an input signal, a preamplifier circuit for amplifying an output signal of the signal input circuit, and the preamplifier circuit An audio of a circuit board group comprising: an amplifying element driving circuit for driving an amplifying element connected to a subsequent stage based on the output signal of the amplifying element; and a rear amplifying circuit having an amplifying element for amplifying the output signal of the amplifying element driving circuit A mounting structure in a device, wherein the circuit board group includes the rear-stage amplifier circuit, and a component board mounting surface is disposed along a substantially vertical direction; the signal input circuit; the front-stage amplifier circuit; The amplifying element drive circuit is included, and is arranged connected to the first substrate so that its component mounting surface is orthogonal to the component mounting surface of the first substrate in plan view. The second substrate is formed in a substantially rectangular shape, the signal input circuit is disposed in a region near one side surface on the lower end side, and in the vicinity of the other side surface on the lower end side. The preamplifier circuit is arranged in a region, and the amplifying element driving circuit is arranged in an upper end side region (claim 1).

  According to this configuration, the signal input circuit is disposed on the lower side of the second substrate and in the vicinity of the one side surface, the pre-stage amplifier circuit is disposed on the lower end side of the second substrate and in the vicinity of the other side surface, Since the amplifying element driving circuit is arranged in the upper end side region of the second substrate, the signal input circuit and the pre-amplifying circuit are separated from the amplifying element driving circuit that handles a relatively large voltage and large current audio signal. . Accordingly, it is possible to provide a circuit board group mounting structure that can suppress problems such as oscillation of audio signals that occur due to the proximity of each circuit and that can output audio signals with good sound quality. .

  According to a preferred embodiment, the input signal is input to the signal input circuit via a first joint member, and an output signal of the amplifier driving circuit is output to the amplifier circuit via a second joint member. The first bonding member may be provided on a lower end surface of the second substrate, and the second bonding member may be provided on the other side surface on the upper end side of the second substrate. 2).

  According to a preferred embodiment, the second substrate is constituted by a plurality of individual substrates, and each of the individual substrates may be arranged in parallel to the first substrate.

  According to a preferred embodiment, a power supply board for supplying a power supply voltage to the first board and the second board may be provided below the second board (Claim 4).

  Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the accompanying drawings.

  FIG. 1 is a perspective view of an AV amplifier as an audio apparatus according to the present invention. FIG. 2 is an exploded perspective view of the AV amplifier shown in FIG. 1 and 2, the lower left diagonal direction is referred to as the front side, the upper right diagonal direction is referred to as the back side, and the right side and the left side when viewed from the front side of the AV amplifier.

  An AV amplifier is an audio device that is used in a home theater system or the like, for example. The home theater system can provide a user with a realistic sound field by arranging a plurality of speakers around the user. For example, a DVD player, a television receiver, and a plurality of speakers (all not shown) are connected to the AV amplifier. For example, when the home theater system has a 7.1 channel specification, eight speakers corresponding to the number of channels are arranged.

  When a video signal and an audio signal are input from a DVD player, the AV amplifier processes the audio signal from the DVD player and outputs them to each speaker, and also processes the video signal from the DVD player and receives it as a television receiver. Output to the machine.

  As shown in FIG. 1, this AV amplifier has a main body 1 formed in a substantially rectangular parallelepiped shape. On the front of the main body 1, there are a power switch 2, a display unit 3 for displaying various operation states, a volume knob 4 for adjusting the volume level, various switches 5 for setting various operation states, and the like. Is provided.

  1 and 2, the main body 1 includes a main chassis 11, a front panel 12, a right side panel 13, a left side panel 14, a rear panel 15, and an upper panel 16 (not shown in FIG. 2). The general shape of the main body 1 is formed by combining and fixing them. The main chassis 11, the front panel 12, and the like are generally made of, for example, hard aluminum having high rigidity. The right side panel 13, the left side panel 14, and the upper panel 16 may be integrally formed.

  A front bracket 17 is attached to the back side of the front panel 12. The front bracket 17 is provided with a front mounting board 18 on the surface on the front panel 12 side. The front mounting board 18 has a power switch 2, a display LED constituting the display unit 3, a volume knob 4, Various switches 5 (not shown in FIG. 2) and the like are mounted.

  A rear bracket 19 is mounted on the back side of the rear panel 15. The rear bracket 19 is provided with a rear mounting board (not shown) on the rear panel 15 side surface, and a plurality of signal input / output terminals (not shown) are mounted on the rear mounting board. Yes.

  The main chassis 11 serves as a support member for supporting various electronic components and various printed boards provided in the main body 1. As shown in FIG. 2, the main chassis 11 includes a substantially rectangular bottom plate portion 20, and a right side plate portion 21 and a left side plate portion 22 that extend in the orthogonal direction from the left and right ends of the bottom plate portion 20. That is, the main chassis 11 is formed in a shape in which a substantially U-shape is inclined 90 degrees in a front sectional view. Four leg portions 23 (see FIG. 1) having a predetermined height are attached to the back side corners of the main chassis 11. In addition, a video signal processing board 24 for processing video signals is provided inside the main chassis 11.

  A sub chassis 25 is attached to the main chassis 11 in a region on the front side of the bottom plate portion 20. FIG. 3 is a perspective view of the sub-chassis 25 and the components attached thereto, as viewed from obliquely upward on the rear side. The sub-chassis 25 includes a bottom plate portion 26, a front plate portion 27 extending in the orthogonal direction from the front side end of the bottom plate portion 26, a rear plate portion 28 extending in the orthogonal direction from the rear surface side end of the bottom plate portion 26, and the bottom plate portion. The right side plate portion 29 and the left side plate portion 30 extend in the orthogonal direction from the left and right ends of the H.26. That is, the sub chassis 25 is formed in a substantially box shape without an upper lid.

  A main transformer 31 is provided on the back side of the front plate portion 27. The main transformer 31 is for stepping down and insulating the input power supply voltage (for example, AC 100V commercial power supply voltage). Two sub-transformers 32 are respectively provided on the left and right sides of the main transformer 31. The sub-transformer 32 is for further stepping down the voltage stepped down by the main transformer 31 to a predetermined voltage and insulating it.

  An opening 28 a is formed in the rear plate portion 28 so as to extend almost entirely. Two heat sinks 33 and 34 are attached along the opening 28 a inside the rear plate portion 28. Each of the heat sinks 33 and 34 has a flat plate-like base portion 35 and a plurality of flat plate-like extending portions 36 extending from the base portion 35. Each of the heat sinks 33 and 34 is attached to the rear plate portion 28 so that the back surface of the base portion 35 faces the opening 28 a of the rear plate portion 28.

  An audio circuit board group 37 is provided outside the rear surface of the rear plate portion 28. The audio circuit board group 37 is composed of a plurality of circuit boards for modulating and amplifying an audio signal as an input signal and outputting it to each speaker (not shown). More specifically, the audio circuit board group 37 includes a first amplification board 38 and a second amplification board 39, a module board 40, and a power supply board 41. The audio circuit board group 37 corresponds to the “circuit board group” recited in the claims, and the first and second amplification boards 38 and 39 also correspond to the “first board”, and the module board 40. Corresponds to the “second substrate”.

  The first and second amplification substrates 38 and 39 are disposed along the surfaces of the base portions 35 of the heat sinks 33 and 34, respectively. The first and second amplification substrates 38 and 39 include a power transistor 42 formed of a plurality of field effect transistors (FETs). Each power transistor 42 has a plurality of terminals extending from its main body connected to the upper and lower ends of the first and second amplification substrates 38 and 39, while the surface of the main body is the surface of the base 35 of the heat sinks 33 and 34. Have been in contact with.

  The module substrate 40 is disposed so as to be orthogonal to the component mounting surfaces of the first and second amplification substrates 38 and 39 in plan view. The module substrate 40 includes, for example, seven individual substrates 40a, 40b, 40c, 40d, 40e, 40f, and 40g corresponding to the seven channels, and each individual substrate 40a to 40g has the same configuration, Channel signal processing is performed.

  The power supply board 41 is disposed along the substantially horizontal direction from the lower ends of the first and second amplification boards 38 and 39 and at the lower ends of the individual boards 40a to 40g. The power supply substrate 41 is a substrate that supplies a predetermined power supply voltage to each of the individual substrates 40 a to 40 g and the first and second amplification substrates 38 and 39.

  FIG. 4 is an external view of the module substrate 40. As shown in FIG. 4, a first connector 43 for inputting an audio signal (input signal) is provided on the lower right portion of the module substrate 40. A second connector 44 for signal monitoring is provided on the lower left portion of the module substrate 40. Further, a third connector 45 for signal output after amplification is provided on the upper left end of the module substrate 40.

  When the module substrate 40 is attached to the first or second amplification substrate 38, 39 and the power supply substrate 41, the first connector 43 and the second connector 44 are connected to the respective connectors 41a (see FIG. 3) provided on the power supply substrate 41 side. See). The third connector 45 is joined to connectors 38a and 39a (see FIG. 3) provided on the first or second amplification substrate 38 or 39 side.

  FIG. 5 is a diagram showing a block configuration of the audio circuit board group 37.

  Conventionally, as shown in FIG. 8, the entire AV amplifier for seven channels is divided into two parts between a pre-driver circuit 87 and a power transistor driver circuit 88, and further, a power transistor driver circuit 88 and an amplifier circuit. The 89 part is divided into 4 channels in units of 2 channels and is configured by a total of 5 substrate groups. However, the AV amplifier according to the present invention has a conventional method of dividing the entire AV amplifier for 7 channels. Is completely different.

  That is, as shown in FIG. 5, in this embodiment, the entire AV amplifier for seven channels is divided into two between the power transistor driver circuit 48 and the amplifier circuit 49, and the amplifier circuit 49 is further divided into two parts. In addition, the portion of the differential input circuit 46 to the power transistor driver circuit 48 is divided into seven in units of channels, and is configured by a total of nine substrate groups.

  With this configuration, the first and second amplification boards 38 and 39 constituting the amplifier circuit 49 are substantially one board using the rear plate portion 28 of the subchassis 11 as shown in FIG. Thus, the amplifier circuit 49 and the heat sinks 33 and 34 can be made smaller in volume than in the prior art.

  In the conventional configuration, as shown in FIG. 7, the heat sink 78 is a rectangular parallelepiped block, and the amplifier circuit board 83 is attached to both side surfaces on the long side of the block. In the present embodiment, a dead space is likely to occur inside the shape, and the overall capacity tends to increase. However, in this embodiment, the first amplification substrate 38, the heat sink 33, and the second amplification substrate 39 are sandwiched between the rear plate portion 28 and the second amplification substrate 39. Since the heat sinks 34 are arranged side by side, the dead space can be reduced as much as possible, thereby enabling the volume of the amplifier circuit 49 and the heat sinks 33 and 34 to be reduced.

  In the present embodiment, the two heat sinks 33 and 34 are not connected to each other as in the prior art, and are arranged in a line in the sub chassis 25. There is also an advantage that heat is efficiently radiated by ventilation.

  Further, the module boards 40a to 40g constituting the differential input circuit 46 to the power transistor driver circuit 48 for each channel are arranged in a compact rectangular parallelepiped board in consideration of the flow of audio signals, as will be described later. Each circuit of the differential input circuit 46 to the power transistor driver circuit 48 is suitably arranged and created. As shown in FIG. 3, each of the module substrates 40 a to 40 g has one side in the longitudinal direction with respect to the first and second amplification substrates 38 and 39 on the substrate surface of the first and second amplification substrates 38 and 39. Since the connectors 38a and 39a are vertically opposed to each other, the distance protruding backward from the substrate surfaces of the first and second amplification substrates 38 and 39 is about the width of each of the module substrates 40a to 40g. It has become shorter.

  In this embodiment, since the portion of the differential input circuit 46 to the power transistor driver circuit 48 for 7 channels protrudes to the rear side of the subchassis 25, this portion has a larger volume than the conventional configuration. In FIG. 3, the entire structure including the heat sinks 33 and 34, the first amplification substrate 38 and the second amplification substrate 39, the module substrates 40 a to 40 g and the power supply substrate 41 arranged with the rear plate portion 28 of the sub chassis 25 interposed therebetween. The volume is nearly 50% smaller than the conventional configuration shown in FIG.

  Hereinafter, the relationship between the block diagram of FIG. 5 and the substrate configuration will be described in detail.

  The module substrate 40 (individual substrates 40a to 40g) includes a differential input circuit 46, a pre-driver circuit 47, and a power transistor driver circuit 48, respectively. The differential input circuit 46 corresponds to the “signal input circuit” in the claims, the pre-driver circuit 47 also corresponds to the “preamplifier circuit”, and the power transistor driver circuit 48 also corresponds to the “amplifier element”. It corresponds to a “driving circuit”.

  The differential input circuit 46 is a circuit for modulating an audio signal input via the power supply board 41 and the first connector 43. The pre-driver circuit 47 is a circuit for amplifying the voltage (amplitude) of the audio signal from the differential input circuit 46. The power transistor driver circuit 48 is a circuit for driving the power transistor 42 at the subsequent stage. The power transistor driver circuit 48 may include a temperature compensation circuit.

  The first and second amplification substrates 38 and 39 have an amplification circuit 49 including a power transistor 42. The amplifier circuit 49 is a circuit that further amplifies the current component of the audio signal output from the power transistor driver circuit 48. The amplifying circuit 49 corresponds to a “second-stage amplifying circuit” in the claims.

  The first amplification substrate 38 includes a circuit configuration corresponding to the individual substrates 40a to 40d among the seven individual substrates 40a to 40g, and the second amplification substrate 39 is an individual among the seven individual substrates 40a to 40g. A circuit configuration corresponding to the substrates 40e to 40g is included. That is, the output of each power transistor driver circuit 48 on the individual substrates 40 a to 40 d is input to each amplifier circuit 49 on the first amplifier substrate 38 via the third connector 45. The outputs of the power transistor driver circuits 48 of the individual substrates 40e to 40g are input to the amplifier circuits 49 of the second amplifier substrate 39 via the third connector 45.

  Here, although not shown in FIG. 4, electronic components such as resistors, transistors, and capacitors are mounted on the module substrate 40 on a predetermined wiring pattern. As shown in FIG. 4, the differential input circuit 46 is arranged in the vicinity of the first connector 43 and in the lower right region on the lower end side of the module substrate 40. The arrow Y shown in FIG. 4 schematically shows the signal flow, but the signal input from the first connector 43 changes its direction upward and leftward in FIG. Proceed to 47.

  The pre-driver circuit 47 is disposed in the lower left area on the lower end side of the module substrate 40. The signal (see arrow Y) input from the differential input circuit 46 changes direction toward the left in FIG. The second connector 44 is provided for signal monitoring as described above, and can extract a signal at the output stage of the pre-driver circuit 47. As indicated by the dotted line X, the signal traveling along the arrow Y proceeds to the upper power transistor driver circuit 48 via a wiring pattern (not shown) formed on the solder surface in the vicinity of the second connector 44.

  The power transistor driver circuit 48 is disposed in the upper end side region of the module substrate 40. The signal input from the pre-driver circuit 47 via the wiring pattern, as indicated by an arrow Z, proceeds to the third connector 45 in the left direction so as to detour once in the right direction. Then, the signal is output to the first or second amplification substrate 38 or 39 via the third connector 45.

  As described above, the audio signal traveling on the module substrate 40 is directed to the vicinity of the center of the module substrate 40 in the differential input circuit 46, but changes its direction immediately before being output to the predriver circuit 47. Make a U-turn and go downward. And it goes to the power transistor driver circuit 48 with the wiring pattern of a solder surface. That is, the signal traveling on the module substrate 40 proceeds in a form separated between the differential input circuit 46 and the pre-driver circuit 47 and the power transistor driver circuit 48.

  As described above, the audio signal traveling through the differential input circuit 46 travels as far as possible from the power transistor driver circuit 48. That is, in the module substrate 40, each circuit is arranged so that the input signal and the output signal are separated as much as possible. Therefore, the audio signal traveling through the differential input circuit 46 passes through the power transistor driver circuit 48. It is less affected by a relatively large current audio signal that travels.

  For example, in the module substrate 40 </ b> A shown in FIG. 6, the pre-driver circuit 47 is disposed on the upper side of the differential input circuit 46, and the power transistor driver circuit 48 is disposed on the left side of the differential input circuit 46 and the pre-driver circuit 47. . In the module substrate 40A having such a circuit arrangement, when a relatively large voltage audio signal is output from the third connector 45, the audio signal traveling through the power transistor driver circuit 48 jumps to the pre-driver circuit 47 at a high frequency. (See the dotted arrow Y ′ in FIG. 6), the audio signal itself may oscillate.

  On the other hand, in this embodiment, the occurrence of oscillation or the like is caused by shortening the distance between the power transistor driver circuit 48 and the power transistor 42 (by shortening the routing of the wiring pattern in the power transistor driver circuit 48). Can be suppressed. In addition, since the area surrounded by the path (see arrow Y in FIG. 4) from the differential input circuit 46 to the pre-driver circuit 47 is small in the module substrate 40A, the occurrence of oscillation and the like can be suppressed.

  Further, according to the present embodiment, the power transistor driver circuit 48 is connected to the amplification circuit 49 of the first or second amplification substrate 38 or 39 via the third connector 45. Therefore, unlike a conventional configuration (see FIG. 7), an audio signal having a relatively large voltage and current is not transmitted through the cable 90, and the signal line of the audio signal is shortened. Therefore, it is possible to suppress the adverse effect of the large voltage and large current signals on the input signal.

  Further, according to the present embodiment, the differential input circuit 46, the pre-driver circuit 47, and the power transistor driver circuit 48 are grouped for each channel, and the respective circuits are arranged on a plurality of individual substrates 40a to 40g. Therefore, the volume of the audio device main body can be reduced as compared with the case where the differential input circuit 46 and the pre-driver circuit 47 are configured with a single module substrate 40 over the total number of channels as in the conventional configuration. Can be miniaturized.

  Further, since the module substrate 40 is configured by one individual substrate distributed for each channel, for example, when one individual substrate fails, it is only necessary to replace the failed individual substrate. It can be set as the structure excellent in maintainability.

  Of course, the scope of the present invention is not limited to the embodiment described above. For example, the number of module substrates 40 is not limited to the number shown in the above embodiment.

1 is a perspective view of an AV amplifier as an audio device according to the present invention. FIG. 2 is an exploded perspective view of the AV amplifier shown in FIG. 1. It is the perspective view which looked at the subchassis and the component accompanying it from back side diagonally upward. It is a figure which shows the block structure of an audio | voice circuit board group. It is an external view of a module substrate. It is an external view of another module substrate. It is a disassembled perspective view which shows an example of the conventional AV amplifier. It is a figure which shows the block configuration of the audio circuit board group of the conventional AV amplifier.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main body 11 Main chassis 25 Subchassis 33, 34 Heat sink 37 Audio circuit board group 38 1st amplification board 39 2nd amplification board 40 Module board 40a-40g Individual board 41 Power supply board 42 Power transistor 43 1st connector 44 2nd connector 45 Third connector 46 Differential input circuit 47 Pre-driver circuit 48 Power transistor driver circuit 49 Amplifier circuit

Claims (4)

A signal input circuit for inputting an input signal, a preamplifier circuit for amplifying the output signal of this signal input circuit, and an amplifier connected to the subsequent stage based on the output signal of this preamplifier circuit A mounting structure for an audio device of a circuit board group, comprising:
The circuit board group includes:
A first substrate including the latter stage amplifier circuit and having a component mounting surface disposed along a substantially vertical direction;
The signal input circuit, the preamplifier circuit, and the amplifier driving circuit are connected to the first board so that its component mounting surface is orthogonal to the component mounting surface of the first board in a plan view. And a second substrate arranged
The second substrate is formed in a substantially rectangular shape,
The signal input circuit is disposed in a region near one side surface on the lower end side, the preamplifier circuit is disposed in a region near the other side surface on the lower end side, and the amplifier driving circuit is disposed in an upper end region. A mounting structure for a circuit board group in an audio device. The input signal is input to the signal input circuit via a first joining member,
The output signal of the amplifying element driving circuit is output to the amplifying circuit via a second joining member,
The first joining member is provided on a lower end surface of the second substrate,
The circuit board group mounting structure for audio equipment according to claim 1, wherein the second bonding member is provided on the other side surface of the upper end side of the second substrate. The second substrate is composed of a plurality of individual substrates,
The circuit board group mounting structure in an audio device according to claim 1, wherein the individual boards are arranged in parallel with the first board.   4. The circuit in an audio device according to claim 1, wherein a power supply substrate for supplying a power voltage to the first substrate and the second substrate is provided below the second substrate. 5. Board group mounting structure.

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