Boom boxes - mic in / line in

[kahunabean]

Ages ago all portable CD/Cassette players used to have microphone inputs. Now I reckon its very rare - just saw a bunch of Sony boomboxes in Baker St store with 'MD Link - Line in' - is Line in identical to a microphone input ? I vaguely thought the expected strength of the signal coming in was different. Please enlighten me !

[mac309]

I could be wrong on this, but i think that a line-in socket is for a '(pre-)amplified' signal from other audio devices, where as the mike socket requires an un-amplified signal because will be amplified by the device to which the socket is connected to.

[xyzzy@bok]

agree with mac, you need a variable preamp unit between mic and line in.

[smorodina]

Without getting too technical, I hope, a line in socket usually needs an input voltage of about 500mV or half a volt. This is what is put out by the 'line out' sockets of hi-fis, videos, walkmen etc. A microphone only puts out a few millivolts so needs to be amplified to line level if used with a line in socket. If the equipment has a 'mic' socket, this socket will have an extra built in pre-amplifier circuit. As xyzzy implied, you can buy microphone pre-amps to use with equipment that has no 'mic' input.