This circuit uses a single chip, IC BA3812L for realizing a 5 band graphic equalizer for use in hi-fi audio systems. The 5 band graphic equalizer is applicable for radio cassette players, home stereo systems and car stereo systems. This device features: low distortion and low noise, wide operating power supply voltage range (3.5V to 16V), low current dissipation (5 mA), wide dynamic range (VOM = 2.1Vrms/VCC = 8V), and built-in input and output buffer amplifiers.
The BA3812L is a five-point graphic equalizer that has all the required functions integrated onto one IC. The IC is comprised of the five tone control circuits and input and output buffer amplifiers. The following pdf file contains detail information about Circuit Diagram for 5 band graphic equalizer using a single IC/chip (BA3812L). The circuit given in the diagram operates around the five frequency bands: 100Hz, 300Hz, 1kHz, 3kHz, 10kHz.