2 channel audio mixer circuit using transistors

This 2 channel audio mixer circuit is based on the 2n3904 transistors which forms 2 preamplifiers. The first preamplifier of the 2 channel audio mixer circuit has a high gain and can be used for microphone input, and the second one can be used to control the input of the audio level.
This two channel audio mixer require a power supply with the output voltage between 9 to 12 volts . For the audio signal you can use a CD player, mp3 player or other audio device and for the microphone you can use a normal dynamic microphone .