[Ti] external microphone jack on Ti 1 GHz

[Chris Olson]

On Sep 8, 2005, at 5:26 PM, Henry Kalir wrote:

> Thanks. I did located it prior to posting my  original message, and  
> had inserted the external mic's plug into it. Now, while the  
> earphones part of the set worked very well (when plugged into the  
> earphone jack), the microphone does not seem to work when plugged  
> into that jack.
>
> Does anyone have any experience/advice?

The audio line in on the PowerBook G4 accepts line-level stereo  
signals for connecting stereo equipment to the computer.

If you want to use an external mic on line in you need a powered  
microphone with the following specs:

maximum input signal amplitude 2 Vrms (5.65 Vpp), +8 dbu peak
input impedance 30 kilohms
channel separation greater than 60 dB
recommended source impedance 2 kilohms or less
ground noise rejection greater than 40 dB
frequency response 5 Hz to 20 kHz, +0.0, –0.5 dB
distortion below –80 dB
signal to noise ratio (SNR) greater than 90 dB A-weighted

Alternatively you can get a USB mic and disable the internal  
microphone in System Prefs.
--
Chris