[wellylug] HW specs - Line In/Out and radios etc.

[Carl Turney]

Hello,

Any one know the voltage (etc) specs (e.g. compatibility) on the Line In 
and Line Out of PC sound cards and laptops, particularly in relation to...

- the 3mm stereo plugs on external PC speakers, and earphone sockets on 
transistor radios etc.
and
- the RCA in and outs of home stereo systems
and
- those 6mm professional-studio-type headphones.

I had thought that Line Out and Headset were quite different, but my new 
Acer laptop manual gives the impression they are the same.

Am thinking about a variety of connections in this regard.  And vaguely 
recall burning out some sound components, probably by porting headphone 
out to line in, many years ago.  (May not have involved computers at 
all, at the time.)

Thanks very much,

Carl