From: Norbert_Hahn@nospam.invalid   
      
   Randy Yates  wrote:   
      
   >"Richard Crowley"  writes:   
   >   
   >> "Randy Yates"  wrote ...   
   >>> Is the phantom power supplied by many PA boards used to power the active   
   >>> (MOSFET) device commonly found in electret condenser mic elements?   
   >>   
   >> Yes. That is probably the most common use of phantom power today.   
   >>   
   >> It is also used to power the active circuitry (voltage and/or current   
   >> amplification and/or impedance buffering, etc. etc.) for other kinds   
   >> of mics such as some models that put out line-level for driving very   
   >> long lines, and impedance conversion/voltage amplification for non-   
   >> condenser mics like ribbons, etc.   
   >>   
   >> It is also used for charging the condenser element in non-electret   
   >> microphones.  Probably even more uses that I can't remember this   
   >> morning.   
   >   
   >Thanks for the confirmation and education, Richard! Before you wrote   
   >this, I didn't even know there were "non-electret" condenser mics. And I   
   >guess that C = Q / V means V = 0 if Q = 0 (i.e., you have to power the   
   >bloody things).   
      
   There is two more type of condensor mic which don't use DC at all:   
   Both types use a low voltage RF generated by a low-noise RF oscillator.   
      
   The mic capsule of a RF condensor mic is part of a resonant circuit   
   that modulates the frequency of the oscillator signal. Demodulation   
   yields a low-noise audio frequency signal with a very low source   
   impedance.   
   In the other type of RF condensor mic the capacitance of the mic   
   capsule is used to modulate the amplitude of the RF oscillator.   
      
   Norbert   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)