The PC Technology Guide
- Features and components of a modern PC sound card. Includes graphics, diagrams and an integrated glossary.
- http://www.pctechguide.com/44SoundCards.htm

Echo Audio
- Designs and manufactures DSP based audio software and hardware.
- http://www.echoaudio.com/

Ego Systems
- Manufactures desktop media production hardware and software.
- http://www.esi-pro.com/

Audiotrak
- Sound and audio cards for desktop PCs.
- http://www.audiotrak.de/eng/index.html

Lynx Studio Technology, Inc.
- Designs and manufactures professional, computer related audio products.
- http://www.lynxstudio.com

Creative Technology Ltd.
- Manufactures PC entertainment products with a focus on sound cards, including Sound Blaster.
- http://www.creative.com/

VideoLogic Online
- Manufacture of sound cards and graphic cards.
- http://www.videologic.com/

Digital Audio Labs
- Sells products that offer a wide range of hardware-based solutions for PCs, used primarily by professional sound recording organizations and individuals.
- http://www.digitalaudio.com/

ESS Technology, Inc.
- PC audio solutions based on the ESS chip platform.
- http://www.esstech.com/

Timur Tabi's Crystal Semiconductor and OS/2
- Information and opinions regarding Crystal Semiconductor chips for OEM sound cards.
- http://www.tabi.org/timur/crystalos2.html