What's that for?
Depending on the type of sound card that you have purchased, you should have a number of different connections available to you on the card's mounting bracket. The figure below shows the connections available on our test card, an AOpen AW744 Pro.
From left to right, this card features an S/PDIF out, line in, front out (line out), rear out (line out), microphone in, and a game and midi port. Some more professional sound cards, such as the Creative SoundBlaster Platinum, also feature front-loading boxes (that fit into your computer's CD drive bay) that hold more connectivity options for the musically minded.
S/PDIF: the Sony/Philips Digital Interface is a connection used to transport a pure digital signal from your sound card to another device, such as a digital stereo receiver or even a DAT machine. Our test card came with an optical type of connection, but some cards also utilise a more common RCA connection.
Line in: this jack utilises a 3.5mm connection and allows you to record from external audio devices such as tape decks or CD players.
Line out: most newer sound cards (such as our test card) have two of these 3.5mm jacks. They are used for connecting your speakers, with one jack providing a signal for the front channel and the other for the rear.
Microphone: once again, this a 3.5mm jack and is simply used for hooking up a microphone.
Games/midi: this port is a 15-pin D-sub connection and serves two purposes. It facilitates a game pad or joystick for the gamer, or an electronic keyboard for the musician.
What goes where?
With the advent of digital music for-mats such as MP3 and WMA, computers can now contain vast libraries of music that have either been ripped from a CD collection or downloaded from the Internet. This means that a lot of people want to include their PC as part of their overall stereo system. How do you do this? To connect your computer to your stereo system you need to go from the line-out of your sound card to the auxiliary or CD input on the stereo's receiver or amplifier, as shown in the figure below.
If you will be connecting to a regular pair of computer speakers, then the only thing you will need to do is attach them to your line-out port via its supplied cable. Some speakers also support four speakers or surround sound, in which case you can connect the speaker system to both of the line-out ports on your card (as is the case with our test card).
If you want to connect a record player to your sound card, you won't be able to do so unless you run it through a pre-amplifier or an audio mixer, whose output should in turn be connected to your card's line in.
What sort of cable?
Chances are, when you purchase a sound card you won't have all the cables you'll need. The following types of cables are the ones that are most likely needed for your sound card, and can be purchased from most good electronics stores.
1. The most common type of cable with which you need to be familiar is used when hooking up your PC to your stereo. It contains a 3.5mm stereo plug on one end (for plugging into your line out or in jack) and two RCA plugs on the other (for connecting to your stereo device).
2. This coaxial cable can be used on sound cards that have an RCA type of digital-out interface.
3. This optical cable can be used on sound cards that have an optical digital-out interface.
4. Typical computer speaker systems use this type of cable. Both ends contain a 3.5mm stereo connection.