Simple electret/dynamic mic preamp

Started by Crontox102098, October 16, 2014, 05:05:50 PM

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Crontox102098

Quote from: anotherjim on October 24, 2014, 08:58:07 AM
They don't let you ground the capsule either?
Crontox - those are Phantom powered circuits - I though you wanted to use line inputs of the mixer?

Something else to be careful of is relative polarity of your DIY mic's. I think the standard is with a positive going pressure wave on the element, the hot output wire should go positive, although the practical thing is to ensure mic's in close proximity to each other should have the same polarity. If they are opposite polarity you can seriously weaken the overall sound from the mixer due to phase cancellation

Watch out for electret circuits that require the so called " Linkwitz" mod - where the polarity is reversed by changing which output pin is connected to the can. This is done to preserve polarity of the can when using the built in JFET as a source follower.
Otherwise, where the can can't be grounded anyway, you can just reverse the connections since the electret and the JFET inside are electrically symmetrical.



Ya, anotherjim. I wanted a little circuit where i can connect a little electret to put in my mixer, i did it with the circuit who i posted many days ago (INVERTING the pin 3 and 2 in the opamp). But... connecting the electret with this little circuit:
http://www.epanorama.net/circuits/ElectretMicBalanced.pdf
And putting it in my phantom powered mixer works better than my preamp. It's really noiseless compared with my preamp.

Cheers!
I'm Carlos.

I speak spanish, just in case you do not understand what I say.