On 16/05/2011 16:52, Michael Watterson wrote:
> On 16/05/2011 16:33, Oli Glaser wrote:
>> I'm not sure about the above - what makes you say this?
>> I am aware of a couple of unusual types but AFAIK, the vast majority of
>> condenser mics use the standard 48V phantom power present on most
>> preamps/mixing desks. The current is pretty low, generally being
>> supplied through pins 2 and 3 via ~6K65 resistors.
> That's the standard desk power.
>
> It's nothing whatsoever to do with what the raw capsule needs.

I'm aware of that - that's why I mentioned that some equipment takes=20
advantage of the fact that most mics don't need the full 48V.

> An Electret only needs an FET with 1.5V supply as isolation. Via
> resistor from 48V desk instead of internal AA cell or button cell(s) it
> would be 0.5mA to 10mA max depending on circuit.
>
> A true condenser mic needs high voltage on the plates and an amplifier.
> Newer designs may only take a couple of mA. Older ones might take more
> than 20mA.

Are you saying then that a "true" condenser mic will not work with 48V?
What voltage do they need? Do you have any links to information on this?

> Most modern cheaper so called "condenser" mics are just electret with a
> fet and big resistor to cut down voltage.
>

Yes. I was thinking of the more expensive, studio quality mics though.=20
Not your average electret PC mic that only needs the supply for FET bias.

--=20
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