Your Computer’s Audio Connections
Computer audio involves both output and input connections. No matter how sophisticated your PC's sound system, audio connections — both input and output — are made by plugging things into the appropriate jacks in the console, connecting your input and output devices to your computer:
Audio input: Supplied by a microphone.
A microphone connects to the computer's microphone jack by using a standard audio mini-DIN connector.
Audio output: Supplied by headphones, left-right speakers, or full-on-wake-up-the-neighbors surround sound.
Both headphones and speakers use the Line Out, headphone, or speakers jack. Speakers may also need to be plugged into the wall for more power.
The Line In connector is used to connect any non-amplified sound source, such as your stereo, VCR, or phonograph — or a tiny dog waiting inside a parked car or another noise-generating device.
If your PC sports SPDIF connectors, you can optionally use digital audio devices for your computer sound. The digital audio devices must also have SPDIF connectors, and you must use special (and not cheap) fiber optic cable to connect these high-end toys:
Plug optical audio input cables into the computer’s SPDIF In connection. To use the computer’s optical audio output, plug the cable into the SPDIF Out connector.
Be careful not to bang, touch, or taunt the clear glass ends of the optical cable. Better cables come with little protective caps that you can keep on the ends when the cable isn’t connected.