Need info about mic impedance 1

[inthedark]

Got a desktop with:

MOTHERBOARD PIII-3754LMR
SystemBoard pc133 Socket 370 M754 series

The manufacturer (AMPTRON) WAS UNABLE TO TELL me what is the impedance of the mic that I should use!

Welcome any help.
Thanks

 

[hotfusion]

Almost certainly 'low impedance' - 150 to 500 ohms would be fine, this is fairly standard now and is typical of most microphones. Indeed, a high impedance mic is a bit of an unusual device now and they are only made for backward compatibility with valve or mosfet input stages. In any case, if you wrongly choose low imp., the worst will be a slightly lower output wheras if you wrongly buy high imp., the quality will be affected as well. Low imp. is the safe bet. My suggestions are what I would try myself. If incorrect, I welcome corrections to my rather limited knowledge. Andy.

 

[inthedark]

Thank you, Hotfusion for your succinct explanation.
Any hint on what is the actual lowest impedance for microphones ?
Could it come down to 8 ohms?

 

[hotfusion]

No, you'd then be in the realms of speaker impedances. I think 150 ohms is the lowest you are likely to encounter. To put it into perspective, high impedance in this case would be in the region of 50,000 ohms or 50K for short. 1,000 or less would be fine, it really isn't that critical, as long as you are at the correct end of the scale. My suggestions are what I would try myself. If incorrect, I welcome corrections to my rather limited knowledge. Andy.