This is the diagram of 5 band graphic equaliser circuit. The circuit is based on operational amplifier, the NE5532 or LM833 is the right choice for low cost op-amp chip with fairly good quality output. Each IC contains dual op-amps circuit, so you will need 4 ICs of NE5532 or LM833 to build this 5 band graphic equaliser.
For maximum audio performance, use:
- Regulated power supply circuit (use LM78xx)
- Use MKM type of nonpolar capacitor
- Use tantalum type of bipolar capacitor (electrolytic capacitor)
- Use metalfilm type of resistor
More explanation about this circuit work: Download the document
Datasheet document: NE5532 datasheet / LM833 datasheet