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PrometheusG5

macrumors member
Original poster
Jun 23, 2004
84
0
San Francisco, CA
I know there was a thread about this a while ago...

But why does the line-in jack on my PowerBook G4 accept input from line-in mics? The line-in will work when I am recording from my stereo, for example, but in using a regular microphone, it doesn't register. I have to use either a USB or Bluetooth set to record in. :confused:
 
PrometheusG5 said:
I know there was a thread about this a while ago...

But why does the line-in jack on my PowerBook G4 accept input from line-in mics? The line-in will work when I am recording from my stereo, for example, but in using a regular microphone, it doesn't register. I have to use either a USB or Bluetooth set to record in. :confused:

you need a pre-amp.


you can buy usb line in's that don't require a pre-amp for $40.
 
Mic level is very much lower than line level, it requires a pre-amp to raise it to line level (Unity Gain). Your line-in expects a signal strength at line level, mic level is too quiet.

Mics are physical transducers, they use mechanical and eletro-magnetic properties to produce electrical signals from the vibrations of sound, but even very expensive mics only produce mic-level signals and therefore require a pre-amp.
 
Ah...that makes perfect sense. I was using mic in and line-in interchangeably. So when I connect from my receiver to line-in, it is already amplified, correct?
 
Yes, your hi-fi uses an integral pre-amp to level out oll the slight differneces in all the units before passing the signal to your power amp to throw it at the speakers, the signal from your reciever is a pre-amped signal automatically.
 
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