Line In is the input of any device (not just electronic) in which the level of the output signal is proportional to the level of the input. In other words, this is an input that gets into the one where the signal (by default) is not processed in any way. On computer sound cards line input Usually it is a blue jack type connector. Used to connect a guitar, CD player, radio and other devices to the sound card, the output signal of which does not require additional processing.
Instructions
1. The line input is usually turned on by default, and if you don’t hear sound when you connect the device, then you need to make sure in the future: - whether the drivers are installed on your sound card?- Is the line input set to line (for some sound card utilities)?- Is its volume set in the mixer?
2. As for the drivers, they must be supplied on a disk along with the sound card, or be pre-installed on your computer (if it is the latest). Otherwise, you need to find out the sound card model and download required driver from the Internet.
3. For some equipment manufacturers, special utilities, advanced analogues of the Windows mixer, are installed together with the drivers. Let's say Realtek. In such cases, you need to run this program and see if the line input is activated. The shortcut to this program, as usual, is located in the system tray next to the clock. In the settings window that opens, check the box or click the “enable” button next to the line input icon (blue input). After this, it should turn on. In the same program, open the mixer or go to the appropriate settings section. Here you need to make sure that the volume control corresponding to the linear input is raised. Otherwise, raise it.
4. If you do not have additional utilities installed, or you do not know how to launch them, you can use the system mixer. It is located at: For Windows XP: Start > Settings > Control Panel > Sounds and Audio Devices > tab: Volume > Advanced...The system mixer window will open. Find the inscription “Lin. entrance". Below it you will see a volume scale and a checkbox with the inscription “Off”. You need to uncheck the checkbox next to this inscription, and move the volume slider to the volume level you need. For Windows 7: Start > Control Panel > Hardware and Sound > under the “Sound” inscription, click: “volume settings”. Next, under the words “Line input”, raise the volume slider to the desired level.
Adding linear entrance to an audio device will allow you to use it as an energetic speaker system for computer. You will be able to listen to the signal from the sound card, say, through a receiver or radio.
Instructions
1. Unplug the device you want to turn into computer speakers, from the network. Open its case. Drill a hole in the back wall for the cable through which the sound signal will be sent.
2. Take headphones whose speakers are damaged, but the cable is intact. Cut off the speakers and tin the wires going to them. Do not use a lighter or a knife to clean them - in the first case they may stop tinning, and in the second they will be damaged. Press them against a piece of wood with a soldering iron richly coated with rosin, and the insulation will be removed from the wires without damaging them. After this, tin them as usual.
3. Thread the cable through the hole in the housing made in step one. Tie it with a knot on the inside so as not to accidentally pull it out. Leave a sufficient length of remaining cable inside. Combine the yellow or gray wires together and connect to the common wire of the audio device. Find the volume control in it. Connect the blue or green wire to the input of the volume control of one of the channels through a 0.1 microfarad capacitor, and the orange or scarlet wire through the same capacitor to the input of the control of the other channel. If the device is monophonic, connect only one of the wires, and isolate the 2nd (or even do not strip or tin). In this case, only one capacitor is required.
4. Assemble the audio device, set the volume control to zero, connect it to the computer and the network, start playing some sound, then set the controls to the desired volume. On the device itself, select a mode in which the amplifier is turned on, but no signal from the built-in sources is received. If the monitor is a tube monitor and the receiver or radio speakers do not have magnetic shielding, install the device away from the monitor. Also, do not place magnetic storage media near it.
Video on the topic
Pay attention!
Do not work under voltage.
Instructions
The line input is usually turned on by default, and if you do not hear sound when you connect the device, you need to make sure of the following:
Are drivers installed on yours?
Is the line-in input set to line-in (for some sound card utilities)?
Is it output in the mixer?
As for the drivers, they must be supplied on a disk along with the sound card, or be pre-installed on yours (if it is new). Otherwise, you need to find out the sound card model and download the necessary driver from the Internet.
For some equipment, along with drivers, special utilities are extended analogues of the Windows mixer. For example, Realtek. In such cases, you need to run this program and see if the line input is activated. The shortcut to this program is usually located in the system tray next to the clock. In the settings window that opens, check the box or click the “enable” button next to the line input icon (blue input). After this, it should turn on. In the same program, open the mixer or go to the appropriate settings section. Here you need to make sure that the volume control corresponding to the line input is raised. Otherwise, pick it up.
If you do not have additional utilities installed, or you do not know how to launch them, you can use the system mixer. It is located at:
For Windows XP: Start > Settings > Control Panel > Sounds and Audio Devices > Tab: Volume > Advanced…
The system mixer window will open. Find the inscription “Lin. entrance". Below it you will see a volume scale and a checkbox with the inscription “Off”. The checkbox next to this inscription must be unchecked, and the volume slider must be moved to the volume level you require.
For Windows 7: Start > Control Panel > Hardware and Sound > under “Sound” click on “volume settings”. Next, under the words “Line input”, raise the volume slider to the required level.
Sources:
- Recording guitar via line input
Line input to sound device The computer is mainly used to connect microphones. Its configuration is carried out without using any special utilities.
Instructions
Make sure that the driver for your sound card has been installed correctly. To do this, open the Add Hardware Wizard, if devices without software your sound adapter is not listed, which means everything was installed correctly.
If the wizard prompts you to install the device driver, insert the software disc into the drive, or specify the path to the folder with drivers on your hard drive. You can also use an internet connection. After installing the driver, restart your computer.
Find the microphone connector on your sound card; it usually has an icon with a corresponding image or is labeled with the abbreviation mic. Connect the device to it, check its operating condition and configure the line input. To do this, open the Sounds and Audio Devices control panel menu.
If you have headphones with a microphone and speakers, it's tempting to connect both devices and use them depending on the time of day without having to constantly plug and unplug.
If your audio system supports multi-channel audio (most often, Realtek HD Audio is used everywhere now) - this is not difficult to do. The solution is to switch the computer's audio system to multi-channel (quadraphonic) mode and reassign the properties of the connectors on the computer through the audio driver settings panel.
I’ll show you how to do this using the example of the most popular operating room Windows systems XP. In Windows 7 and 8 everything is also simple.
Modern desktop computers usually have three audio connectors on the back panel and two on the front. Often the connectors on the front panel are not connected and we will not consider them.
The connectors on the rear panel have different colors:
blue - linear input;
green - line output(headphone output);
red - microphone input.
First of all, go to the Control Panel and click the “Sound and Audio System” button (in other operating systems just “Sound”). Select the tab or "Audio" and in it "Play audio". You can quickly get to this location by pressing right click mouse on the system gray speaker icon at the bottom right of the panel near the clock and select “Adjust audio parameters”.
Then launch the Realtek HD Audio Manager by right-clicking on the orange speaker icon on the panel next to the clock and selecting "Audio Manager". Click on the wrench button in the "Audio Inputs/Outputs" tab and check the "Connect automatic pop-up dialog for a turned on device" checkbox. Now, when you plug cables into the audio connectors, the system will prompt you to choose what exactly you plugged there. You also need to select “4CH speakers” from the drop-down list above the audio system testing picture.
Then, in turn, connect the green headphone connector to the green computer connector, the red microphone connector to the red computer connector, and the speaker audio cable to the blue computer connector (you don’t need to turn on the speakers yet). At the same time, in the pop-up window, indicate with a tick which device you connected.
For the green connector, select “headphone output,” for the blue connector, “output to the front speakers” (or vice versa), and for the red connector, select “microphone input.”
That's it! Now you can check - the sound will come from both the speakers and headphones at the same time! In the evening, you can turn off the speakers without disconnecting them from the computer. Happy listening!
Line input is an analog input of an acoustic signal that does not require additional processing. This connector on a personal computer is intended for connecting acoustic equipment, such as CD and DVD players, radios, etc.
Purpose
Line input (stereo) is a standard interface designed to receive analog signals from various audio devices. This connector is used to connect devices that have a linear output. That is, this is the input of a device whose input signal level is proportional to the output level of the device with which the connection occurs. These connectors are used to connect a guitar, radio, CD player, etc. to the sound carriage, the output signal of which does not require additional processing.
Connector design 
On sound cards of personal computers, the line input is represented by a blue jack (female) connector. This socket is located on the panel at the rear system unit. Most laptops do not have a line-in input, but do have jacks for connecting a microphone and headphones. They are usually located on the front or left side panel of the laptop.
Setting up your computer's line input
If you connect to your PC external device To re-record the sound, you will need to make certain settings. This procedure can be performed using standard utilities, which are in every operating system, or using professional software. First of all, check the drivers for your sound card. It often happens that they are installed incorrectly. To do this, go to Device Manager and find your sound card there. If it functions normally, then the drivers are installed correctly. If not, you will need to perform the installation again. Insert the plug of the connected device into the line input (blue) of the sound card. After that, through the “Toolbar”, go to “Sounds and Audio Devices” and select the “Audio” tab. Next, in the recording section, you should find the connected device and open its volume menu. Then the mixers for configuration will be highlighted. Set them according to your preference. That's it, you can start capturing sound. 
Why do you need a multi-channel linear input?
This question can often be heard from people who have little interest in music. However, any music lover knows: thanks to this input you can connect speakers to a DVD player, home theater or personal computer in multi-channel mode (standard 5.1 or 7.1), which will provide high-quality surround sound. The device to which the speakers are connected must have a built-in decoder for multi-channel audio and, accordingly, the necessary connectors.
Conclusion
To summarize, we note that the system of connectors corresponding to the linear input and output allows you to create a whole network of different acoustic devices that will work together. They are able to complement each other and enhance acoustic signals.
Line input is an analog input of an acoustic signal that does not require additional processing. This connector on a personal computer is intended for connecting acoustic equipment, such as CD and DVD players, radios, etc.
Purpose
Line-in (stereo) is a standard interface designed to accept input from a variety of audio devices. This connector is used to connect devices that have a device. That is, this is the input of a device whose input signal level is proportional to the output level of the device with which the connection occurs. These connectors are used to connect a guitar, radio, CD player, etc. to the sound carriage, the output signal of which does not require additional processing.
Connector design
On personal computers, the linear input is represented by a blue jack (female) connector. This socket is located on the panel at the back of the system unit. Most laptops do not have a line-in input, but do have jacks for connecting a microphone and headphones. They are usually located on the front or left of the laptop.
Setting up your computer's line input
If you connect an external device to your PC to record audio, this will require some setup. This procedure can be performed using standard utilities found in every operating system, or using professional software. First of all, check the drivers for your sound card. It often happens that they are installed incorrectly. To do this, go to Device Manager and find your sound card there. If it functions normally, then the drivers are installed correctly. If not, you will need to perform the installation again. Insert the plug of the connected device into the line input (blue). After that, through the “Toolbar”, go to “Sounds and Audio Devices” and select the “Audio” tab. Next, in the recording section, you should find the connected device and open its volume menu. Then the mixers for configuration will be highlighted. Set them according to your preference. That's it, you can start capturing sound.
Why do you need a multi-channel linear input?
This question can often be heard from people who have little interest in music. However, any music lover knows: thanks to this input, you can connect speakers to a DVD player, home theater or personal computer in multi-channel mode (standard 5.1 or 7.1), which will provide high-quality surround sound. The device to which the speakers are connected must have a built-in decoder for multi-channel audio and, accordingly, the necessary connectors.
Conclusion
To summarize, we note that the system of connectors corresponding to the linear input and output allows you to create a whole network of different acoustic devices that will work together. They are able to complement each other and enhance acoustic signals.
