3-Band Graphic Equalizer Circuit

Audio and Amplifier | By: Diagram mania

Unlike the 10-band graphic equalizer in our previous circuit that use a gyrator circuit, this 3-band graphic equalizer circuit uses Baxandall topology, similar with the Baxandall tone control but with additional mid frequency control. The figure below shows the schematic diagram of the circuit.

3 band graphic equalizer circuit circuit schematic

The operational amplifier employ an LF351 IC chip, but any low noise op-amp will be suitable for this equalizer application. Unlike in the application of  10 channel equalizer, the passive components  in this 3-bands graphic equalizer circuit are not critical since this circuit doesn’t need a critical frequency band separation.  Resistors with 5% tolerance are more than enough, and ceramic capacitors with 10% tolerance will be adequate. Off course you can use better component but the performance improvement won’t be noticeable. This circuit need only a single supply, so this would be great for car audio or simple home audio application. [Circuit's schematic diagram source: circuitstoday.com]