Here's the schematics:
The circuit is powered by a 9V battery. There is a voltage divider that gives 4.5V between R4 and R5, this voltage is applied to the negative pole of the electret microphone (V2). The rest of the circuit is the first stage of an instrumentation amplifier built with a TL-082 op-amp and the condensers are there to remove the 4.5V bias before sending the signal to the mono jack.
The microphone by itself works perfectly, when it's connected to the amplifier the computer only gets a small noise. Could any you guys help?