In article ,
Arfa Daily wrote:

"Dave Plowman (News)" wrote in message
...
In article ,
Arfa Daily wrote:
I've never found them to be particularly heat sensitive within common
sense limits, but note that they are polarity sensitive, as they
contain a FET preamp which is phantom powered via the output terminal
...

A few electret mic are phantom powered but the majority use a form of
AB power for the capsule.


I'm using the term "phantom powered" loosely Dave, in that the audio out
is floating on the DC in, because there are only two connections, one
of which is the FET drain terminal, the series DC 'feed' resistor
therefore actually being the drain load resistor. The other terminal
(also the capsule case) is of course ground or FET source. Where there
is this type of power / signal setup, it is often considered
generically, to be 'phantom powered' ... Excuse my ignorance, but
what's "AB power" ?

Not a good idea to use it where mics are concerned, though. Can cause
confusion.

Other thing is not all electrets have the same ground polarity. But
hopefully are marked.

AB or T power is where the DC is fed up the audio pair on a balanced mic.
Dates from before true phantom and has the disadvantage it puts DC across
a moving coil mic - although when it was common many used a PS for each
mic, rather than getting it from the mixer.
Arfa

--
*Age is a very high price to pay for maturity.

Dave Plowman London SW
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