JPH09298791A - Adaptor for stereo headphone - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow the user to listen to a stereo sound with very high sound quality with a headphone by suppressing transmission loss and distortion of a sound signal so as to enhance performance of an amplifier to the utmost. SOLUTION: An input terminal 20 is connected to a speaker output terminal of an amplifier, and made up of a right channel input positive terminal 21a, a negative terminal 21b, a left channel input positive terminal 22a, and a negative terminal 22b independently. Damping resistors 41, 42 are respectively directly connected to the left right channel input positive terminals 21a, 22a. The positive terminals 26a, 27a of jacks 26, 27 are connected to other terminals of the damping resistors 41, 42, and negative terminals 26b, 27b are connected to the negative terminals 21b, 22b of the input terminal 20. Since the damping resistors 41, 42 are connected directly, no loss is caused and since left and right channels are separated, left right crosstalk is not caused.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stereo headphone adapter for enabling stereo sound to be heard with high quality using headphones.

[0002]

2. Description of the Related Art The quality of stereo reproduced sound depends on the performance of sound sources such as CD players and record players, preamplifiers, power amplifiers, speakers, etc., but it is said that the sound quality is most affected. It is a tiered speaker. However, the sound quality of speakers currently on the market is not always satisfactory for music enthusiasts who pursue sound quality, and the current situation is that trial and error is performed in order to listen to a sound that suits one's taste. Is. On the other hand, in recent years, high-performance headphones have become commercially available, and are widely used as an alternative to speakers even among music enthusiasts.
Normally, headphones are used by connecting them to the headphone jack of the amplifier, but generally the headphone output of the amplifier is
There are many secondary characteristics compared to the speaker output, and it was difficult to bring out the full performance of the amplifier. So, take the output from the speaker output terminal of the amplifier,
An adapter for driving headphones has also been devised.

[0003]

However, since the conventional adapter of this type only considers dropping the speaker output to the allowable input range of the headphone,
There is a problem that transmission loss or distortion of the audio signal occurs in the adapter, and sufficient sound quality cannot be obtained. The present invention has been made in view of the above problems, and can suppress transmission loss and distortion of an audio signal and maximize the performance of the amplifier. Therefore, an extremely high-quality stereo audio can be heard through headphones. An object is to provide a headphone adapter that can be used. Another object of the present invention is to provide a headphone suitable for such a headphone adapter.

[0004]

SUMMARY OF THE INVENTION The present invention is a stereo headphone adapter for damping a speaker output from a stereo amplifier and outputting it to headphones.
An input terminal portion connected to the speaker output terminal of the amplifier, the positive electrode terminal and the negative electrode terminal for the right channel input and the positive electrode terminal and the negative electrode terminal for the left channel input which are independently provided, and the right channel input Of the damping resistor for the right channel whose one end is directly connected to the positive electrode terminal of the left channel, the damping resistor for the left channel whose one end is directly connected to the positive electrode terminal for the left channel input, and the positive electrode terminal of the damping resistor for the right channel. A headphone output terminal for the right channel whose negative electrode terminal is connected to the other end and whose negative electrode terminal is connected to the negative electrode terminal for inputting the right channel, and a positive electrode terminal, which is provided independently of this, is connected to the other end of the damping resistor for the left channel. An output terminal section including a headphone output terminal for the left channel whose negative electrode terminal is connected to the negative electrode terminal for inputting the left channel, and Characterized in that by comprising.

According to the present invention, in addition to the above structure, a common negative electrode terminal is provided in the input terminal portion, a standard headphone output terminal is provided in the output terminal portion, and a right channel positive electrode terminal of the standard headphone output terminal is provided in the standard headphone output terminal. Connect to the positive terminal of the headphone output terminal for the right channel, connect the left channel positive terminal of the standard headphone output terminal to the positive terminal of the left channel headphone output terminal, and connect the negative terminal of the standard headphone output terminal to the common negative electrode. It is characterized by being connected to a terminal. Characterized by

According to the present invention, in addition to the above configuration, the input terminal section is provided with first and second switching terminals for switching output for each channel, and the output terminal section is connected to a speaker for each channel. A speaker output terminal for the same channel, the positive electrode terminal of the speaker output terminal of the same channel is connected to the first switching terminal, the positive electrode terminal of the input terminal and the second switching terminal are connected, and the same channel The negative electrode terminal of the speaker output terminal is connected to the negative electrode terminal of the input terminal, and the speaker output is obtained from the speaker output terminal by short-circuiting the first and second switching terminals. .

That is, in this type of adapter, it is expected that a low-loss cable is used from the speaker output terminal of the amplifier to the input terminal of the adapter. Therefore, damping of speaker output from the input terminal (positive terminal) is expected. The biggest problem is the transmission loss in the wiring up to the target resistance. In this respect, according to the present invention, since the damping resistor is directly connected to the input terminal (the positive terminal of the left and right channels) to which the speaker output of the high power from the amplifier is introduced,
There is virtually no power loss from these positive terminals to each damping resistor. In addition, the loss of the low-power audio signal from the damping resistor to the positive terminal on the output terminal side can be kept within an almost acceptable range.

Further, according to the present invention, the left and right independent speaker outputs output from the amplifier are guided to the headphone output terminal while maintaining the left and right independence, so that left and right crosstalk does not occur. , Very high resolution and distortion-free audio output can be obtained.

Therefore, according to the present invention, there is no transmission loss or distortion of the audio signal, and the speaker output can be utilized to maximize the performance of the amplifier, thereby producing a stereo audio with extremely high sound quality. It is possible to provide a headphone adapter that can be heard with headphones and a headphone suitable for the adapter.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a diagram showing a configuration example of an audio system to which the present invention is applied. This system includes a power amplifier 1 that outputs an audio signal from a sound source such as a CD player, a headphone 3 that is driven by a speaker output from the power amplifier 1, and a speaker output that is interposed between the power amplifier 1 and the headphone 3. 3 to the headphone adapter 2 for reducing the input level to the allowable input level 3.

The speaker output terminal 10 on the back surface of the power amplifier 1 is a positive terminal 11a and a negative terminal 11 of the right channel.
b, the positive electrode terminal 12a and the negative electrode terminal 12b of the left channel
And are separated by the left and right channels. Corresponding to this, the input terminal 20 of the adapter 2 is also composed of a right channel positive electrode terminal 21a and a negative electrode terminal 21b, and a left channel positive electrode terminal 22a and a negative electrode terminal 22b, which are separated by the left and right channels. A speaker cable 4 having a low impedance is connected between them.

The output terminal 25 of the adapter 2 comprises headphone jacks 26 and 27, which are independent on the left and right. Jack 3 of the headphone 3 connected to this output terminal 25
The left and right channels 1 and 32 are also separated, and the audio signals are transmitted to the electroacoustic conversion units 34 and 35 of the headphone 3 via the cable 33 in the separated state.

FIG. 2 is a circuit diagram showing an internal circuit of the adapter 2. Damping resistors 41 and 4 are connected to the positive terminals 21a and 22a of the channels of the input terminal 20, respectively.
One end of 2 is directly connected. Each damping resistor 41, 4
The other end of 2 is connected to the positive terminals 26a and 27a of the jacks 26 and 27 of the respective channels via wirings 43 and 44, respectively. The negative terminals 21b and 22b of the respective channels of the input terminal 20 are connected to the negative terminals 26b and 2 of the jacks 26 and 27 of the respective channels via the wirings 45 and 46, respectively.
7b.

The damping resistors 41 and 42 lower the speaker output level to the headphone output level to protect the headphone and determine the damping factor. Considering the output wattage of the amplifier and the allowable input level of the headphone. For example, an arbitrary resistance value may be determined from the range of 200 to 600Ω. As these resistors 41 and 42, cement resistors, Teflon film resistors, metal oxide film resistors, etc. can be used, but according to the experiments of the present inventor, winding resistors of silicon film are used for digital sources such as CDs. It was best to use a metal clad resistor connected in series to this as an analog source. As the wirings 43 to 45, shield copper wires described later are used.

When such an adapter 2 is used, the speaker output of the power amplifier 1 can be used,
In addition to being able to bring out the performance of the power amplifier 1 almost perfectly, since the damping resistors 41 and 42 are directly attached to the speaker output introduction portions (positive terminals 21a and 22a), the introduction portions to the resistors 41 and 42 are connected. Is almost zero. Further, since the left and right channels are completely separated, it is possible to create the same conditions as those for driving the speaker, and the distortion due to crosstalk is almost zero.

In order for the headphone 3 to sufficiently bring out a high-quality audio signal with low loss and low distortion through the adapter 2, it is desirable that the headphone 3 is also a left and right independent type. As the cable 33 for the headphones 3, for example, a shield wire as shown in FIG. 3 can be used. That is, in the cable 33, a paper tape 52 is wound around a copper core wire 51, fixed with glue, completely dried, and then covered with a shield member 53 of mesh copper wire. The tube 54 of FIG. The core 51 and the shield member 53 are separated on the input side, and the core 51 and the shield member 53 are connected on the output side. A total of four cables 33 are used for the positive and negative electrodes of the left and right channels. Cable 3 like this
By constructing No. 3, the aggregating action that causes an increase in impedance is reduced to the utmost and the sound quality is significantly improved. A similar cable is used for the wires 43 to 46 to the output in the adapter 2.

FIG. 4 is a diagram showing a main part of an adapter 2 according to another embodiment of the present invention. In this embodiment, 200 to 600Ω is selected so that the optimum resistance value can be selected for the system.
One end of each of a plurality of damping resistors 41a, 41b, 41c, ... Which have different resistance values and are selected at appropriate intervals are directly connected to the positive electrode terminal 21a of the input terminal 20. The other ends of the damping resistors 41a, 41b, 41c, ... Are connected to the terminal plate 61, and the wiring 43 is connected to the damping resistor 41 having an arbitrary resistance value via the terminal plate 61. Although only the right channel configuration is shown in the figure, the left channel has a similar configuration. According to this embodiment, there is an advantage that the optimum resistance value for the system can be easily selected.

FIG. 5 is a circuit diagram of an adapter 2 according to still another embodiment of the present invention. In this embodiment, common negative terminals 71a and 71b are newly added to the input terminal 20 shown above, and a standard headphone jack 72 is provided on the output terminal 25. Then, the right channel positive electrode terminal 72a of the standard headphone jack and the positive channel terminal 26a of the right channel jack 26 are connected by a wiring 73, and the left channel positive electrode terminal 72b and the left channel jack 27 of the standard headphone jack are connected. Terminal 27a
And the common negative terminal 71a, 71b and the negative terminal 72c of the standard headphone jack 72 are connected to the common ground. According to this configuration, in addition to the left / right separated type headphones 2 described above, it is also possible to listen using normal headphones having a standard jack. Even in this case, the effect of being able to use the speaker output of the amplifier with low loss can be obtained although the independence of the left and right is lost.

FIG. 6 is a circuit diagram showing a main part of an adapter 2 according to still another embodiment of the present invention. In this example,
In addition to the headphone jack 26, the output terminal 25 is provided with a speaker output positive electrode terminal 81a and a negative electrode terminal 81b, and the input terminal 20 has output switching terminals 82a (first switching terminals) and 82b (second switching terminals). Terminals). The output switching terminal 82b is connected to the right channel positive electrode terminal 21a of the input terminal 20 through the wiring 83, and the output switching terminal 82a is the speaker output positive electrode terminal 8 of the output terminal.
It is connected to 1a through wiring 84. Further, the speaker output negative electrode terminal 81b is connected to the input right channel negative electrode terminal 21b through a wire 85. The output switching terminals 82a and 82b can be appropriately short-circuited from the outside of the adapter 2 by a copper wire 86 or the like. Although only the right channel configuration is shown in the figure, the left channel has a similar configuration.

According to this structure, the following effects can be obtained. That is, if the adapter 2 has a configuration as shown in FIG.
Speaker output terminal 1
It is necessary to reconnect the speaker to 0. In this regard, according to the present embodiment, by short-circuiting the output switching terminals 82a and 82b from the outside of the adapter 2, an amplifier output can be obtained from the speaker output positive terminal 81a and the negative terminal 81b. Terminal 81
A speaker may be left connected to a and 81b, and terminals 82a and 82a are provided only when listening with headphones.
Since it suffices to open 82b, the usability is improved as compared with the previous embodiment.

The reason why the switch is not used for switching is that in the case of the switch, since point contact is inevitably made, it is impossible to transmit a speaker output of high power without loss. As a method of short-circuiting the output switching terminals 82a and 82b, for example, as shown in FIG. 7A, a copper wire 86 is inserted into the side holes of the terminals 82a and 82b and both terminals 82a and 82b.
In addition to the method of inserting so as to straddle b, as shown in FIG. 7B, a short circuit plate 87 made of copper is provided between both terminals 82a and 82b.
It is conceivable to use a method such as a short circuit.

[0022]

As described above, according to the present invention,
By driving the headphones using the speaker output of the amplifier, both the performance of the amplifier and the performance of the headphones can be maximized, and the speaker output of high power from the amplifier is introduced to the input terminal. Since the damping resistors are directly connected, the power loss from the input terminal to each damping resistor can be suppressed, and the left and right independent speaker outputs output from the amplifier are guided to the headphone output terminal while maintaining the left and right independence. Therefore, crosstalk on the left and right does not occur, the separation power is extremely high, and a sound output without distortion can be obtained. Further, according to the present invention, there is an effect that even an amplifier having no headphone terminal can listen with headphones. In the experiments conducted by the present inventor as well, it was possible to reproduce a high-quality sound that could not be obtained by conventional headphone listening, such as sound extension, spread, depth perception, and sound localization.

[Brief description of drawings]

FIG. 1 is a diagram showing a main configuration of an acoustic system according to an embodiment of the present invention.

FIG. 2 is a circuit diagram of a headphone adapter in the system.

FIG. 3 is a diagram showing an example of a cable used in the system.

FIG. 4 is a circuit diagram showing a main part of a headphone adapter according to another embodiment of the present invention.

FIG. 5 is a circuit diagram of a headphone adapter according to another embodiment of the present invention.

FIG. 6 is a circuit diagram showing a main part of a headphone adapter according to another embodiment of the present invention.

FIG. 7 is a perspective view of an output switching terminal of the adapter.

[Explanation of symbols]

1 ... Power amplifier, 2 ... Headphone adapter, 3 ...
Headphones, 4, 33 ... Cables, 41, 42 ... Damping resistance.

Claims (4)

[Claims] 1. A stereo headphone adapter for damping a speaker output from a stereo amplifier to output to a headphone, the right headphone input adapter being connected to a speaker output terminal of the amplifier and provided independently of each other. An input terminal portion including a positive electrode terminal, a negative electrode terminal, a positive electrode terminal and a negative electrode terminal for left channel input, a damping resistor for the right channel whose one end is directly connected to the positive electrode terminal for the right channel input, and the left channel input A damping resistor for the left channel whose one end is directly connected to the positive electrode of the right channel, and a right channel whose positive electrode terminal is connected to the other end of the damping resistor for the right channel and whose negative electrode terminal is connected to the negative electrode terminal for inputting the right channel. Headphone output terminal and a positive electrode terminal provided separately from the headphone output terminal for the left channel damping Wherein the negative terminal is connected to the other end of the anti-left channel negative terminal connected to the adapter for stereo headphones, characterized by comprising and an output terminal portion including a headphone output for the left channel input. 2. A common negative electrode terminal is provided in the input terminal portion, a standard headphone output terminal is provided in the output terminal portion, and a right channel positive electrode terminal of the standard headphone output terminal is a positive electrode terminal of the right channel headphone output terminal. Wherein the left channel positive electrode terminal of the standard headphone output terminal is connected to the positive electrode terminal of the left channel headphone output terminal, and the negative electrode terminal of the standard headphone output terminal is connected to the common negative electrode terminal. The stereo headphone adapter according to claim 1. 3. The input terminal section is provided with first and second switching terminals for switching output for each channel, and the output terminal section is provided with speaker output terminals for speaker connection for each channel, and the same. The positive electrode terminal of the speaker output terminal of the channel is connected to the first switching terminal, the positive electrode terminal of the input terminal is connected to the second switching terminal, and the negative electrode terminal of the speaker output terminal of the same channel is connected. The stereo headphone according to claim 1 or 2, wherein a speaker output is obtained from the speaker output terminal by connecting the negative terminal of the input terminal and short-circuiting the first and second switching terminals. Adapter. 4. The first jack composed of a positive electrode terminal and a negative electrode terminal of the right channel and the second jack composed of a positive electrode terminal and a negative electrode terminal of the left channel are separated and independent from each other. Headphones adapted to the stereo headphone adapter described in the paragraph.