JPH0641384Y2 - Sound quality adjustment circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a sound quality adjusting circuit such as a graphic equalizer.

<Outline of the Invention> The present invention is a sound quality adjustment circuit that adjusts the sound quality of the left and right channel circuits, so that the sound quality of the left and right channel circuits can be adjusted individually, and the sound quality of one channel circuit can be adjusted for both channels. The present invention provides a sound quality adjustment circuit which enables the sound quality adjustment of any one of them and allows any one of the sound quality adjustments to be arbitrarily selected by a switch.

<Prior Art> FIG. 2 and FIG. 3 show an equivalent circuit diagram of a graphic equalizer which is an example of a conventional sound quality adjusting circuit. Common parts in FIG. 2 and FIG. Is attached.

In FIG. 2, R ₁₁ and R ₂₁ are input resistors, R ₁₂ and R ₂₂ are feedback resistors, VR ₁₁ , VR ₁₂ , VR ₁₃ , VR ₂₁ , VR ₂₂ and VR ₂₃ are variable resistors, and their movers are shown. _{S 11, S 12, S 13} , S 21, S 22, S 23 are connected to a series resonant circuit in the corresponding relationship, respectively. _{F 11, F 12, F 13} , F 21, F 22, F 23 is a coil, a series resonant circuit composed of a capacitor and a resistor, are defined respectively different resonant frequencies. A _11, A ₂₁ is an amplifier.

Then, the input resistor R ₁₁ to the input side of the amplifier A _11, together with the feedback resistor R ₁₂ is connected to the output side, between the input terminals, the series resonant circuit F ₁₁ of the movable element S ₁₁ to S ₁₃ are in correspondence left channel circuit is formed by connecting a variable resistor VR ₁₁ to VR ₁₃ which is connected to to F ₁₃ in parallel relationship, and the input resistor R ₂₁ to the input side of the amplifier a ₂₁ is a feedback resistor to the output side R ₂₂ And the variable resistor VR ₂₁ connected between the input terminals and the series resonance circuits F _{21 to} F ₂₃ in which the movers S _{21 to} S ₂₃ have a corresponding relationship.
The right channel circuit is constructed by connecting ~ VR ₂₃ in parallel.

In the left channel circuit with the above configuration, the input signal from the input resistor R ₁₁ increases the output because the feedback amount of the amplifier A ₁₁ decreases when the resistance value of the variable resistors VR _{11 to} VR ₁₃ is high. If the resistance is low, an amplifier
Since the input impedance of A ₁₁ is lowered by the series resonant circuits F _{11 to} F _{13, the} output is attenuated. That is, as shown in the frequency characteristic diagram of FIG. 4, for example, variable resistors VR ₁₁ and VR
_When the resistance value of ₁₃ is increased, the frequency of the output of the amplifier A _{11 has} the characteristic shown by the line l ₂ . The line l ₂ is a frequency characteristic of the output of the amplifier A ₁₁ in the case where the variable terminal S ₁₁ to S ₁₃ of the variable resistor VR ₁₁ to VR ₁₃ was positioned in the center of the movable range, the mean level of the output Show.

Further, the circuit configuration of the right channel circuit is the same as that of the left channel circuit, and the description thereof will be omitted.

Therefore, the frequency characteristics of the outputs of the left and right channel circuits are the same as those of the variable resistors VR _{11 to} VR ₁₃ , VR provided in both channel circuits.
_{21 to} VR ₂₃ can be adjusted individually.

On the other hand, FIG. 3 is a circuit example of a graphic equalizer capable of simultaneously adjusting the sound quality of the left channel circuit and the right channel circuit.

In FIG. 3, the variable resistors VR ₁ , VR ₂ and VR ₃ have an interlocking relationship with the variable resistors of the left and right channel circuits. That is, the movers S ₁₄ and S ₂₄ , S ₁₅ and S ₂₅ , and S ₁₆ and S ₂₆ are interlocked with each other.

Therefore, the frequency characteristics of the outputs of the left and right channel circuits are adjusted to the variable resistor VR provided in either channel circuit.
₁ ~ VR ₃ can be adjusted at the same time and the same.

<Problems to be Solved by the Invention> In the above conventional graphic equalizer, when a sound field is created by a combination of a power amplifier and a speaker, the sound quality of the left channel and the right channel is adjusted depending on the room condition or the listening position. May or may not need to be separate. At this time, if you want to adjust the left and right channels separately, it is impossible to adjust with the left and right linked graphic equalizer, and if you want to adjust the left and right channels in the same way, adjust the left and right channels with the left and right independent graphic equalizer. There was an inconvenience that the knobs had to be adjusted to the same position.

<Means for Solving the Problem> The present invention provides a plurality of series resonance circuits having different resonance frequencies and a plurality of series resonance circuits between the input terminals of the first amplifier, which correspond to half the series resonance circuits. Between the input terminals of the second amplifier and the first channel circuit configured by connecting the variable resistors in parallel relation to each other, and the first channel corresponding to the remaining half of the series resonance circuit of the series resonance circuit. And a second channel circuit configured by connecting the same number of variable resistors to each other in parallel relation,
In a sound quality adjusting circuit in which the mover of each variable resistor of the second channel circuit is connected to the corresponding series resonance circuit, the second channel is provided between the input terminals of the first amplifier. Additional variable resistors having an interlocking relationship with each variable resistor of the circuit are connected in parallel relation to each other, and half of the series resonant circuits are connected to the series resonant circuits, respectively, and the additional variable resistors of the first channel circuit The mover and the mover of the variable resistor of the first channel circuit are selectively switch-connected by switches, and these switches are interlocked with each other.

<Operation> Therefore, by switching the switches that are interlocked with each other,
You can adjust the sound quality of the left and right channel circuits at the same time, or individually.

<Embodiment> The present invention will be described in detail below with reference to an embodiment shown in FIG. Incidentally, in FIG. 1, parts common to those in FIGS. 2 and 3 are designated by common reference numerals.

In FIG. 1, an input resistor R ₁₁ is connected to the input side of the amplifier A ₁₁ (second amplifier), a feedback resistor R ₁₂ is connected to the output side, and movers S _{31 to} S ₃₃ are provided between the input terminals. Variable resistors VR _{31 to} VR ₃₃ connected to related series resonant circuits F _{11 to} F ₁₃
The left channel circuit (second channel circuit) is configured by connecting the two in parallel.

Further, the input resistance R _{21 is connected} to the input side of the amplifier A ₂₁ (first amplifier).
Is connected to the output side with a feedback resistor R ₂₂ , and the variable resistors VR _{41 to} VR ₄₃ and the variable resistors VR _{44 to} VR are connected between the input terminals.
₄₆ (Additional variable resistor) is connected in parallel and its mover
By connecting S _{41 to} S ₄₃ and movers S _{44 to} S ₄₆ to switches SW _{1 to} SW ₃ whose common terminals are connected to corresponding series resonance circuits F _{21 to} F ₂₃ , respectively, the right channel is connected. A circuit (first channel circuit) is configured.

Then, with the variable resistor VR ₃₁ that constitutes the left channel circuit,
VR ₄₆ , VR ₃₂ and VR ₄₅ , and VR ₃₃ and VR ₄₄ are interlocking with each other, and the switches SW _{1 to} SW ₃ are also interlocking with each other.

In the left channel circuit configured as described above, the frequency characteristics of the output of the amplifier A ₁₁ are linked to each other by the switch S.
W ₁ regardless contact state of the to SW _3, the variable resistor VR ₃₁ to VR
_33, is adjusted by the series resonant circuit F ₁₁ to F _13.

On the other hand, in the right channel circuit, the switches SW _{1 to} SW ₃
Movable contact selective contact S _2, S _4, and when in the S ₆ side, the frequency characteristics of the output of the amplifier A ₂₁ is a variable resistor VR ₄₁ to VR
₄₃ and the series resonance circuits F _{21 to} F ₂₃ .

In addition, the movable contacts of switches SW _{1 to} SW ₃ are selected contacts S ₁ , S ₃ , S ₅
When the side is, the frequency characteristics of the output of the amplifier A ₂₁ is a variable resistor VR ₄₄ to VR _46, is adjusted by the series resonant circuit F ₂₁ to F _23, the variable resistor VR ₄₄ and VR _33, VR ₄₅ and VR ₃₂ and VR
_{Since the 46} and the VR ₃₁ are in an interlocking relationship with each other, the frequency characteristics of the outputs of the left and right channels can be set at the same time and the same by adjusting one of the variable resistors.

<Effects> As described above, according to the present invention, the sound quality adjustments of the left and right channel circuits can be adjusted simultaneously or individually by a simple operation such as switching the interlocking switches. The sound field can be set easily.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a graphic equalizer which is an example of an audio adjusting circuit of the present invention, FIGS. 2 and 3 are circuit diagrams showing a conventional graphic equalizer, and FIG. 4 is an output frequency in FIG. It is explanatory drawing which shows a characteristic. VR ₁ ~ VR ₄₆ ... Variable resistor, A ₁₁ , A ₂₁ ... Amplifier, SW ₁ ~ SW ₃
… Switch, F _{11 to} F ₂₃ … Series resonance circuit, R ₁₁ , R ₁₂ … Input resistance, R ₁₂ , R ₂₂ … Feedback resistance

Claims (1)

[Scope of utility model registration request] 1. A plurality of series resonance circuits having different resonance frequencies, and a plurality of variable resistors corresponding to half the series resonance circuits of the series resonance circuit are connected in parallel between the input terminals of the first amplifier. Between the first channel circuit configured to be connected to the first channel circuit and the input terminal of the second amplifier, the same number of variable resistors as the first channel circuit corresponding to the remaining half of the series resonant circuits of the series resonant circuits. A second channel circuit configured by connecting in parallel relation to each other, and connecting the mover of each variable resistor of the first and second channel circuits to the series resonance circuit in a corresponding relationship. In the sound quality adjusting circuit, the additional variable resistors having the interlocking relationship with the variable resistors of the second channel circuit are connected in parallel between the input terminals of the first amplifier, The mover of the additional variable resistor of the first channel circuit and the mover of the variable resistor of the first channel circuit are selectively switched and connected to half of the series resonance circuits of the oscillation circuit by switches. , A sound quality adjustment circuit characterized by interlocking each of these switches.