This is a very simple preamplifier circuit for condenser microphone. This mic preamplifier also can be used for dynamic microphone.
You can replace the BC549 with BC109C. For better audio result, use ultra low noise transistor BC650C.
This is a video tutorial about how to a very simple audio amplifier based on the LM386 amplifier chip. It can be built for less than $20 (or might be less than $8 in some countries) and used to amplify any low level audio signal including a guitar, bass or mp3 player.
Watch the video: