>  I would like to know what is the actual resistance of a microphone that
> one would use as input to a sound board? My understanding is it should be
> low impedance of about 600 ohms. What does one actually measure with an
> ohm meter?
>
> What is the typical impedance of a sound blaster compatable sound card
> microphone input?

        Unfortunately you are talking about impedance and not only resistance.
Resistance is what is easily measured with a multimeter, impedance on the
other hand is the DC resistance plus the AC resistance. What makes it hard
is that the AC resistance is dependent on the frequency being used, a device
might have a total impedance of 20 ohms at 20 hertz, but it might have an
impedance of several hundred or even thousand ohms at higher frequencies, or
vice versa. To measure impedance one must choose a frequency to test with,
and then use that with a few basic formulas to find the impedance at that
frequency. It also get more complicated with a specific load being applied.
All in all it is difficult for a person to measure impedance without the
right equipment. As for the sound blaster, yes I believe the input impedance
is 600 ohms, but I may be wrong there, most microphones built for computers
are designed with the correct impedance, I suggest try one, if it has a ton
of hum or takes alot of amplification to hear anything then it is obviously
wrong impedance and design for your board. Please bear in mind that many
sound card microphone inputs are not the greatest, so you might never get a
sound quite as nice as you would like. For a better result, take a preamp
and connect the microphone to it, then connect the preamp out to your line
level in on the sound card, it will probably sound much better. TTYL

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