Sony PCV-MXS20 - Vaio Desktop Computer System Reference Manual page 25

Mic and Headphones Jacks
The microphone and headphones jacks are physically identical, but have
different connections. They are standard 3.5 mm stereo mini-jacks,
located at the front of the computer.
Headphones
Connector
Headphones
Mic
Telephone and Line Jacks
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.
Your computer has only one RJ-11 female phone jack if you have a
HomePNA modem installed. The modem installed on your computer
may differ depending on the configuration you purchased.
Line Phone
✍
Accidentally plugging a phone line from the wall into the modem's telephone jack, and a
telephone into the line jack, does not damage the modem card or telephone equipment.
However, the modem will not work correctly.
Mic
Description
1.0 Vrms (typical).
Electret condenser microphone input.
Identifying Components
13