Matt Mc_Carthy wrote in a message to Roy J. Tellason:

 TW>> I just looked at a SoundBlaster card and the Mike Input is not
 TW>> Stereo. But it is an oldr card. No Fancy Sorround etc. IWhen i go
 TW>> on the Internet later today I will have to check things out.

 RJT> I know the input isn't stereo,  but the mic I have here (which 
 RJT> works) uses a stereo-type plug.  Maybe they're running power to 
 RJT> it on that extra connection,  or something,  I don't know for 
 RJT> sure.  That's why I posted about it in the first place.

 MMC> LOTs of possibilities there!  If that is a 'commercial' electret
 MMC> mike, like you've seen used on stage or in a studio, the third
 MMC> wire MIGHT be just to a ground shield.

Nope!  It's a cheap little thing I picked up at a computer show some years
back,  paid about six bucks for it as I recall.

 MMC> If it is a 'home' mike, the third wire could _still_ be just a 
 MMC> shield lead, especially if there is a battery _in_ the mike
 MMC> itself.

No battery in there.

 MMC> If there is _no_ battery _in_ the mike, then one of those leads is
 MMC> common to ground on the equipment chassis, the second lead
 MMC> connects to B+, and the third lead is capacitor coupled 'audio',
 MMC> and usually connects to a medium or high impedance input.

So I should be able to tell with an ohmmeter,  then?

 MMC> No impedance matching is needed, but connecting to a _low_ 
 MMC> impedance input effectively shorts out the coupling capacitor.   

Ok.  As I posted before,  it works with the sound cards I've tried it with...

Know of any pointers to info regarding the impedances,  levels,  etc. for
typical sound card inputs and outputs?

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