Stereo Line-In Jack - Compaq Armada 7700 Reference Manual

Stereo Line-In Jack

The stereo line-in jack is the input line for an external stereo
player such as a CD player, stereo tuner, or tape deck.
The input device must have a 3.5-mm stereo plug and must supply
line input levels of 0.5 to 4.25 volts. The line output of most stereo
players meets this specification.
CAUTION:
A single sound channel (monaural) plug in the stereo line-in jack
may damage the input device.
10-6 Using Audio Components
Use only a 3.5 mm stereo plug in the stereo line-in jack.