Does somebody have a schematic for a stereo electret condenser microphone?
Electret microphones normally have an inbuilt FET preamplifier. You need to bias it from a quiet power supply of some volts in series with a resistor of a few kohms. Obviously capacitively couple to the following amplifier. Experiment and see what happens. If you start with 10 V and 10 k, you're inlikely to damage anything.