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volts and attenuation for microphone?

qweets

Sep 26, 2010
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Sep 26, 2010
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hello there : )

ive set up this little pre-amp circuit, and it seems to work o.k. i am using a 5v regualated supply.

741pre.jpg


what i have connected to the input is cheap mic capsule from a cheap headset. i beleive the mic is an electret mic. the amp is not distorting as i replaced the 1k (R2) in the diagram to a 4.7k and that has helped allot. ( i am hoping that is the best place to attenuate the the level, before it goes into the amp? i could place a variable there perhaps?)

ive looked around and most descriptions of these electret mics say they need 2v or more.
i have measured the voltage +- at the mic it is just under 5v so that should be o.k.

i wonder, is there anything i can do to tune ths a little better? i thought to replace the mic capsule in the headset with a panasonic WM-55A103.

any ideas would be cool : )
 
Last edited:

Harald Kapp

Moderator
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Nov 17, 2011
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What do you want to tune?
- frequency response?
- gain?
- noise?
 

qweets

Sep 26, 2010
48
Joined
Sep 26, 2010
Messages
48
hi

I think if I get a new capsule WM-55A103 it will sound allot better. i just wondered if all the values seemed o.k.? and if varying the 1k (r2) for pre attenuation before the amp is the best way to do this?
 
Last edited:

BobK

Jan 5, 2010
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Or, calculate it!

The microphone module should indicate what it's output is. Set the gain so that you get the output level you want, presumably something like 1V P-P.

Bob
 
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