This circuit uses a single chip, IC BA3812L to make 5 band graphic equalizer in audio hi-fi system. BA3812L IC is a 5-point graphic equalizer that has all functions integrated on a single IC. This IC is composed of five tone control circuit and input and output buffer amplifier. BA3812L have low distortion, low noise, and wide dynamic range, and is ideal for a variety aperanti Hi-Fi stereo. He also has a wide operating voltage range (3.5V to 16V), meaning he could be adapted for use on most stereo equipment.
The five center frequencies are independently set using external capacitors, and therefore act as an output stage buffer amplifier and tone control section is a series of its own, it is possible to do fine control over the frequency bandwidth. By using two BA3812Ls, you can create a 10-point graphic equalizer. Great header and pieces can be set by external components.
The recommended power supply of 8V, but this circuit can work well for supply voltage 9V. Limit the maximum voltage is 16V.
The circuit is given in the diagram operates in around 5 frequency bands:
100Hz , 300Hz , 1kHz , 3kHz , 10kHz