JP2520212Y2 - Playback equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a reproducing device for selecting and amplifying a plurality of stereo source source input signals, and more particularly to a reproducing device having a high sound quality reproducing function. .

[Prior Art] Conventionally, as this kind of equipment, there is one shown in FIG. In the figure, A1 is PHONO for record players.
An equalizer amplifier that corrects the frequency characteristic of the stereo signal from the terminal, A2 is a tone amplifier for tone control that can adjust the frequency characteristic of the stereo signal to your desired sound quality,
A3 is a power amplifier that drives the speaker and is flat in frequency.

Also, S10 is a functional switch that switches the stereo source signal of each of the CD (compact disc), PHONO, tuner, and tape deck 1 (PLAY), and S5 is the output of the functional switch S10 or the playback output of the tape deck 2. VR2 is a balance volume that adjusts the left and right balance of the stereo source signal, which is a switch that is selectively input to the recording input terminal of deck 1.

Further, S3 and S4 are switches for switching between inserting or directly connecting the tone amplifier A2 between the balance volume VR2 and the power amplifier A3.

Therefore, there are the above-mentioned record player, tuner of FM, AM, tape deck, etc. as the source of input, and the stereo signal from them is selectively switched by the function switch S10 to extract one signal. When the switch S5 is on the side of the terminal a, the volume of the selected signal is adjusted by the volume VR1, and further the stereo left / right balance adjustment is performed by the volume VR2.

When the switch S5 is on the terminal b side, the tape deck player 1 records the sound and the reproduced output is adjusted in volume and balance by the volumes VR1 and VR2.

Here, when the switches S3 and S4 are on the terminal b side,
The tone amplifier A2 adjusts to the desired sound quality, and the signal derived to the switch S4 is a power amplifier with a flat frequency characteristic.
It is amplified by A3 and output to the speaker terminal to drive the speaker.

When the switches S3 and S4 are on the side of the terminal a, the outputs of the volumes VR1 and VR2 are led straight to the switch S4 (referred to as line straight) and directly amplified by the power amplifier A3.

[Problems to be Solved by the Invention] In such a conventional configuration, all stereo source signals are supplied to the volume VR1 for volume adjustment via the function switch S10.

On the other hand, the use of digital technology in audio equipment has also led to the emergence of excellent sources of low noise and high sound quality, such as CDs and DATs (digital audio tapes).

When reproducing such a source source, generally, sound quality adjustment is not required, and since the signal is deteriorated when the tone amplifier A2 is interposed in the signal system, the switches S3 and S4 are switched to the side a to switch the source source. The signal is directly input to the power amplifier A3 without going through the tone amplifier A2.

Therefore, in the configuration of FIG. 4, when reproducing these source source signals, the source source signal (CD in the figure) is selected by the function switch S10.

However, in the function switch S10, a plurality of source source signals are concentrated and led to each fixed contact,
When the CD signal passes through the function switch S10, its sound quality deteriorates.

Further, even when a plurality of analog switch ICs are used for the function switch S10, a plurality of source source signals are input to this IC in the same manner as described above, so that the sound quality of the CD signal deteriorates.

Therefore, even if the source signal from the CD is prevented from passing through the tone amplifier A2 by the switches S3 and S4 to prevent the deterioration of the sound quality, the deterioration of the sound quality cannot be sufficiently prevented by passing through the function switch S10. .

Further, since the stereo source signal passes through the balance adjusting volume VR2, the volume VR2 further deteriorates the sound quality.

[Means for Solving the Problems] Therefore, the present invention has been made in view of the above-mentioned problems, and selects one source source signal to be output among signals input from a plurality of source sources. Means, an extracting means for extracting only a specific source source signal from the plurality of source source signals without passing through the selecting means, the source source signal output through the selecting means, and the specifying through the extracting means Switching means for switching the source source signal output, a tone control circuit for adjusting the sound quality of the source source signal via the selecting means, and amplifying the source source signal and the specific source source signal via the switching means. In a reproducing device including an amplifier circuit, an amplifier circuit via the selection unit, the switching unit, and the tone control circuit, which are paths through which the source source signal passes. There is a normal path that communicates, and a bypass path that communicates with the amplification circuit through the extraction means and the switching means that are paths through which the specific source source signal passes, and the switching means includes the source source signal output and the specific path. A source source signal output is switched and the normal path and the bypass path are switched, and the switching means switches to the normal path side when switching to the source source signal output side and the specific source source signal output. When it is switched to the side, it is characterized in that it is switched to the bypass circuit side.

[Operation] When the switching means is operated to select one stereo source signal including a specific source source signal by the selecting means,
The sound quality of the stereo source signal is adjusted by the tone control circuit, and the signal is input to the power amplifier.

On the other hand, when the switching means is operated to select a specific source source signal without passing through the selecting means, the specific source source signal is extracted by the extracting means and bypasses the tone control circuit to be input to the power amplifier. It

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, the same parts as those in FIG. 4 are designated by the same reference numerals.

The signal of, for example, a CD player having excellent sound quality as a source source is the function switch S10 and the switch S10.
It is supplied to the contact a of the switch S6 without going through. switch
The signal selected by the switch S5 is supplied to the contact b side of S6.

Also, switches S7 and S8 are provided in conjunction with this switch S6, the switch S7 is connected between the sliding terminal of the balance volume VR2 and the ground, and the switch S8 switches between the tone control circuit T1 and the resistor R1. There is.

When the switch S7 is on the a side, the switch S7 is off, the switch S8 switches to the a side (resistor R1 side), and the b
Switch S7 is on and switch S8 is b
Side (tone control circuit T1 side). An intermediate tap is provided at one half of the resistor of the balance volume VR2 and is grounded.

In such a configuration, first, the function switch S1
A case where the stereo source signal is selected by 0 will be described. At this time, by switching the switch S6 to the b side, the switch S7 is turned on in conjunction with this, and the switch S8 is switched to the b side.

Therefore, the balance volume VR2 and the tone control circuit T1 are in an operable state. Also,
Switch S5 is switched to the a side.

Under the above conditions, the function switch
S10 selects the desired one of the source signal sources such as CD, PHONO, tuner, etc., and this selected signal is switched to switch S5,
The volume VR1 is set to a predetermined volume through S6, and the balance volume VR2 is adjusted to set the left and right balance. Further, the tone control circuit T1 adjusts the sound quality to a desired one. Then, the stereo source signal whose volume, balance and sound quality have been adjusted in this way is amplified by the power amplifier A4 and reproduced from the speaker.

Next, the direct CD mode will be described. In this case, by switching the switch S6 to the a side, the switch S7 is turned off in conjunction with this, and the switch S8 is switched to the a side.

Therefore, the balance volume VR2 is bypassed, the tone control circuit T1 does not operate, and the feedback resistor R1 for the proper amplification degree of the power amplifier A4 is connected.

In the above configuration, the volume of the signal from the CD is adjusted by the volume VR1 via the switch S6 without passing through the function switch S10. The signal from the CD passes through the balance volume VR2 and is directly input to the power amplifier A4 without passing through the tone control circuit T1.

From the above, switch S6 is switched to the a side and direct
When the CD mode is selected, the CD signal does not go through the function switch S10, and the balance volume VR2 is automatically deactivated in conjunction with the operation of this switch, and the tone control circuit T1 is bypassed. .

Therefore, the CD signal is amplified by the power amplifier A4 without passing through the function switch and tone control circuit.

Note that the tone control circuit T1 may be maintained in the operating state even in the direct CD mode if necessary.

Next, balance volume for direct CD mode
A circuit example around VR2 will be described.

Here, if the switch S7 is on, the power supply + B turns on the switching transistor Q1 via the resistor R3, the capacitor C1 and the resistor R20 of the filter circuit, and the variable terminal of the balance volume VR2 is dropped to the ground to operate balance If the switch S7 is on the off side, the power supply -B cuts off the switching transistor Q1 to form a balance center balance path regardless of the position of the variable terminal of the balance volume VR2.

Also, a power amplifier that doubles as a tone control circuit
An example of the circuit around A4 is shown in FIG.

Here, when the switch S8 is on the terminal b side, the tone control circuit T1 as the negative feedback circuit of the power amplifier A4
If the BASS and TREBLE circuits of are operating and are on the terminal a side, the tone control circuit T1 does not operate and the negative feedback resistor R
5. Apply appropriate amplification to power amplifier A4 with R6.

However, the variable terminal of the switch S8 is connected to the inverting terminal side of the power amplifier A4, and the input of the signal system is connected to the non-inverting terminal side. The capacitor C2 is for oscillation prevention, and the resistor R4 is for feedback.

[Advantage of Invention] As described above, according to this invention, when a particular stereo source signal such as a CD or DAT is desired to be listened to, the stereo source signal is balanced without passing through the selecting means. Since the adjusting means is inactive and / or the tone control circuit is bypassed and input to the power amplifier, there is no change in sound quality or addition of noise to the speaker output terminal, and there is no nonlinearity in the transmission system. It is possible to eliminate the deterioration of distortion due to sex.

Further, the specific stereo source signal can be selectively output by the selecting means. In this case, the balance adjusting means and the tone control circuit can make balance adjustment and sound quality adjustment.

Therefore, the listener should listen to the sound with less distortion for the particular stereo source signal without the need for balance adjustment and sound quality adjustment, and adjust the balance and sound quality without considering the distortion. Both listening can be selected according to preference. In addition, the listener operates the tone control circuit to adjust the sound quality for a specific stereo source signal, and then operates the switching means to select the specific sound source without performing the sound quality adjustment by the tone control circuit. The stereo source signal can be directly selected and output by the selection means.
Further, by selecting the bypass and operating the switching means again, it is possible to listen with the already adjusted desired sound quality without performing the sound quality adjustment by the tone control circuit.

[Brief description of drawings]

FIG. 1 is a block diagram showing a reproducing apparatus according to an embodiment of the present invention, FIG. 2 is a circuit diagram showing an example of a circuit around a balance adjusting means of the present invention, and FIG. 3 is a view around a power amplifier of the present invention. FIG. 4 is a circuit diagram showing a circuit example, and FIG. 4 is a block diagram showing a conventional reproducing apparatus. A1 …… Equalizer amplifier A3, A4 …… Power amplifier S10 …… Function switch S1, S2 …… Switch T1 …… Tone control circuit VR1 …… Volume VR2 …… Balance volume

Claims (1)

(57) [Scope of utility model registration request] 1. Selection means for selecting one source source signal to be output among signals input from a plurality of source sources,
Extraction means for extracting only a specific source source signal from the plurality of source source signals without passing through the selection means, output of the source source signal via the selection means, and the specific source source signal via the extraction means Switching means for switching between output and
A reproduction device comprising a tone control circuit for adjusting the sound quality of the source source signal via the selecting means, and an amplifier circuit for amplifying the source source signal and the specific source source signal via the switching means, A normal path that is a path through which the source source signal passes, the normal path that leads to the amplifier circuit via the selecting means, the switching means, and the tone control circuit, and the extracting means and the switching means that is a path through which the specific source source signal passes. A bypass path communicating with the amplification circuit via the switching circuit, the switching means switches the source source signal output and the specific source source signal output, and switches the normal path and the bypass path. When switching to the source source signal output side, the switching means switches to the normal path side and outputs the specific source source signal. Reproducing apparatus, characterized in that switching to the bypass circuit side when switched to side.