Request a circuit for connect a carbon microphone to Behringer UCA200 Soundcard

[Lop2Lop]

Hi !
Help me , please !

I have a Behringer UCA200 Sound card , I want to use a Carbon microphone for record using this sound card !
But i think This sound card needs more input power !

I connected a carbon microphone to input of sound card but no sound i received ! (With different modes ! Microphone is intact and well , I tested it !)

But when i connect Mobile/Laptop/... output to Sound card input i receive sound !

I know very little about electronics !

I think i need an Amplifier or pre amplifier! Can you introduce or bring me an amplifier or pre amplifier or any circuit that lets me connect my carbon microphone to my sound card and i receive sound with good power and very low noise !
Sound card input is stereo but i need just one channel !
All information that i know about my sound card :

Connectors : RCA , Unbalanced
Input Impedance : approx. 27K Ohms
Max input level : 2dBV
USB powered , 5v - 100mA

Sorry for bad English !
Thanks so much ♥

 

[BradtheRad]

Most likely you need a microphone pre-amplifier.
A mic produces a weak signal. Maybe 10 mV average amplitude.

Your sound card requires an incoming signal that is 'line level' (on the order of 0.1 to 1 V AC).
When you hook up the other sound sources, they come through audibly, because they produce a sufficiently strong signal.

There are inexpensive pre-amp projects which are built around a transistor (maybe two), or an op amp.
Some schematics can be found at this message board, by doing a search for 'pre-amp'.

Also see the list of similar threads at the bottom of this page.

I have used a cassette recorder to amplify a microphone signal. I press 'Record' and 'Pause'. I plug into the Monitor jack and run the amplified signal to a device which needs line level audio.

It has even worked sometimes by simply using the recorder's built-in mic.

 

[Lop2Lop]

Thanks for reply.
Exactly i need a pre-amp (Battery powered !) , But :
I found some Pre-amps but i don't know which one is good for me !
Which one has low noise and which one can bring me necessary signal and power for sound card !


I said i know very little about electronic ! I need more helps !

Thanks so much !

 

[betwixt]

Carbon microphones have very HIGH output levels. Most likely you are not providing it with enough current. The carbon works as a resistance that varies under sound wave pressure so you have to pass a current through it to turn the resistance into voltage. Try connecting a 1K load resistor in series with it and then providing it with a 5V supply. Please note that this kind of microphone has very low sound quality and is prone to environmental conditions and even orientation.

Brian.