Below is a mic compressor circuit that uses transistors as active components. VR1 and VR 2 is used to control the tone from the microphone, while VR3 and VR4 strengthening works to control the audio signal in the compressor mic. C10 must be used in this circuit.
The circuit I got from my local computer store but I have not tried to assemble this circuit. I am sure this circuit worked perfectly because the kits sold in the market from this circuit.