Sony PCV-E204 Reference Manual - Page 20

12 VAIO MicroTower System Reference Mic, Line In, and Headphones The Mic, Line In, and Headphones jacks are physically identical, but have different connections. They are standard 3.5 mm stereo mini-jacks. Headphones Line In Mic KY0013.VSD Connector Headphones Mic Line In Description 1.0 Vrms (typical) Electrolet condenser microphone input 1.0 Vrms (typical), 10 Kohm impedance Telephone and Line The Telephone and Line jacks are physically identical and have identical connections. They are standard RJ-11 female phone jacks. However, the Line jack is for connecting to a telephone line that comes from the wall, and the Telephone jack is for connecting the computer to a telephone. Line Telephone KY0014.VSD  Accidentally plugging a phone line from the wall into the modem's Telephone jack, and a telephone into the Line jack, will not damage the modem card or telephone equipment. However, the modem may not work correctly.