Connection PC And Stereo System
Usually you have the possibility to connect PC and stereo system analogue or digital.
The starting point on the computer is the sound card, whereby there are two variants:
- internal sound card
external sound card
The internal sound card is either located directly on the mainboard (on-board) or as a plug-in card in the PC. In both cases, the connections are usually located on the back of the PC, often they are also redirected to the front. An external sound card is connected to the computer via USB (or a similar interface), the connections are located on the housing of the sound card.
Contents
Analog
PC
The analog outputs of the sound card are usually in the form of 3.5 mm jacks, the number depending on whether it is a stereo or multi-channel sound card. On virtually all newer computers, the connectors are color-coded in a uniform manner: (see image) pink: microphone input
- blue: Line In
green: Line Out, output for stereo signals to the hi-fi amplifier black: output for rear speakers (multi-channel) silver: output for side speakers (multi-channel) orange: output for centre and subwoofer (multi-channel)
The analogue connections are preferable for use with computer games, as sound cards without Dolby Digital Live or DTS Connect function can only output the game sound in stereo via the digital connection.
If you want to connect your PC to a normal stereo amplifier, you need the green output. The other connections are only needed if you have a corresponding multi-channel receiver or amplifier.
Stereo system
With few exceptions, the analog (stereo) inputs on newer amplifiers are red/white RCA jacks. Usually an AUX (or spare) input is used to connect a PC, if this is not available, another input (e.g. CD, Tape In, Tuner or similar) can be used without any problems. Only phono inputs are not suitable.
A/V receivers and amplifiers usually have a multi-channel input in the form of RCA sockets, which can be used to connect multi-channel sound cards.
Older amplifiers and receivers may have connections in the form of round DIN jacks (often referred to as Band, Aux, and Reserve) that can also be used.
Cables
Which cables you need depends on the connections you have and the transmission you want:
Stereo, RCA inputs on the amplifier/receiver ('standard case):
- To output the sound via the stereo system you need an adapter jack to RCA plug (see picture), which connects the line output of the sound card (usually green) with the input of the amplifier. The RCA plugs are usually color coded:
- rot: rreal analog channel
- white: left analog channel (sometimes also black or grey)
Multi-channel, RCA inputs on the amplifier/receiver:
- For this case, depending on the number of channels, you need several adapters. A 5.1 sound card, for example, usually has three outputs: 1x front left/right, 1x rear left/right, 1x center/subwoofer. The exact assignment can be found in the manual of the sound card. The outputs are then connected to the multi-channel input on the amplifier using several adapters.
Stereo, DIN connections on the amplifier/receiver:
- This is basically where you need a jack to DIN plug adapter. But these are hard to find, so you can use two adapters which are easier to get: 1x jack to RCA plug (see above) and 1x RCA jack to DIN plug (see picture), preferably with four RCA jacks. These are generally assigned as follows:
- white: left channel for playback
- red: right channel for playback
- black: left channel for recording
yellow: right channel for recording If the PC is used for playback only, two of the connectors remain free.
Humming loop
The most common problem that occurs when connecting a computer and stereo system is a hum, caused by a so-called hum loop. This is a grounding problem that occurs, for example, when the PC and amplifier are connected to different sockets (power strips). If it is not possible to connect the devices to the same power strip, you need an isolating transformer, which is inserted between the computer and the system.
If one of the devices has an antenna or cable connection (e.g. computer with TV card), this can also be the cause of a ground loop. In this case you need a sheath current filter (important: with galvanic isolation), which is inserted between the device and the antenna cable.
Examples of sources of supply:
- Isolating transformers:
- Sheath current filter
- In the professional area there are so-called DI boxes:
Digital
PC
Digital outputs are usually optical (TOSLINK connector, more rarely optical jack) or coaxial (RCA jack) in S/P-DIF format and are marked orange.
The sound card transmits only digital signals here, so an external D/A converter is still needed, e.g. in an A/V receiver or amplifier. Some CD players also have digital inputs that use the player's D/A converter and pass the signal to the amplifier in analog form, as do external D/A converters in their own enclosures.
An optical connection can reliably avoid any hum loop that may occur.
As a rule, the D/A converters of high-quality A/V amplifiers in particular are of better quality than simple sound cards such as those integrated on the mainboard of most PCs. Therefore, digital transmission should be preferred.
Sound cards with Dolby Digital Live or DTS Connect can also output the sound of computer games with 5.1 surround sound digitally. Otherwise, additional analog connections must be made for games.
Amplifier
A/V receivers and amplifiers usually have multiple digital inputs that can be connected both optically and coaxially.
Cable
If you want to make an optical connection, you need an optical fiber (FO) cable with TOSLINK connectors (or TOSLINK and optical jack if you have the appropriate output on your sound card). The coaxial connection is established using a coaxial cable (monocinch).
With the help of an adapter, the signal can also be converted between optical and coaxial if required.