When you play audio on your computer, a digital signal travels to the sound card. (Refer back to Chapter 2 for more on sound cards.) The signal is converted to analog and sent to the analog output jacks (typically a line-out and headphone-out), and on some sound cards it may also be passed along without modification to a digital output jack.
When you’re recording, on the other hand, the audio signal is fed into one of the input jacks. If the signal is analog (e.g., feeds from microphones and any equipment with line-out jacks, such as tape decks and stereo receivers), it is converted to digital before it’s passed on to the recording program on the computer. If the incoming signal is digital (e.g., from a MiniDisc player or stereo receiver with digital outputs), it can be passed along without conversion.
Basic sound cards, such as those that ship with most home computers and virtually all notebook computers, use 1/8” mini-phone jacks for all inputs and outputs. A mono jack serves as the microphone input, and stereo jacks are used for the line-in and line-out. Stereo jacks save space because they carry both channels through a single connector. Adapter cables are available to connect stereo 1/8” mini-phone jacks to the separate left and right RCA jacks found on most home stereos.
Higher-end sound cards may include separate RCA jacks for the left and right channels—the same layout found on most home stereo systems. High-end sound cards may also have jacks for digital ...