Almost all new computers come with built-in soundcards. These soundcards work to convert electronic signals into audio output through your computer's speakers or headphones. Even with built-in soundcards, users may opt to use externalized USB sound cards. Basic USB sound cards are inexpensive and easier to install than internal sound cards, making them an ideal upgrade in certain situations.
USB soundcards can have basic or advanced functions. Some USB cards are no bigger than a pen-drive, containing only simple microphone and headphone jacks; other soundcards feature miniature mixing boards, XLR ports, equalizers and 1/4-inch jacks for professional recording.
Typically, external soundcards are bought cheaply with basic features, allowing for a quick fix to a malfunctioning or poor quality onboard soundcard. Less frequently, expensive models are purchased for USB-based professional recording.
USB sound cards are usually compatible with almost any PC and, in many cases, even Macs. As a USB device, most external soundcards feature "plug-and-play" technology for convenient sharing among multiple computers.
Popular USB soundcard models are made by M-Audio, Zalman, Creative Professional and Nortel.
Basic USB soundcards are available at big-name electronics stores like Best Buy and Comp USA. For advanced, high-end USB soundcards, music stores like The Guitar Center are a safe bet.