Audio Mixer Design, Simulation, Testing- Proteus Professional VMS software

This article demonstrates a simple audio mixer design, simulation and testing with real audio file in Proteus Professional.

The design schematics of the audio mixer is shown below-

Fig: audio mixer schematic, design, testing and simulation

In the circuit above two signals has been mixed one is a sinusoid signal and the another is a music audio file in .wav format. These generators are found in the generator palette. These signal are modulated and amplified with gain of 20 by the transistor BC109. The output is taken at the end of capacitor C2. To view all of the the signals an oscilloscope is used which is found in the instruments palette. The port A of the oscilloscope is connected to the sinusoidal signal generator, port B is connected to the audio generator and the port C is connected to the output.

The waveform as seen in the oscilloscope are shown below-

Fig: Sinusoid, Audio, Mixed Output Waveform in Oscilloscope

The yellow colored waveform is the sinusoid signal applied at port A, the blue colored waveform is the audio sound waveform at port B and the third pink colored waveform is the mixed signal at the output taken at port C as described above.

Note that the audio signal that was used here is an music file sampled at 8khz PCM and with mono format. To convert any music file to .wav format with above specification you can use software like Switch Sound File Converter. This software can convert any music file to any other music file extension.