Build Your 5-Band Graphic Equalizer Circuit

Description

An additional graphic equalizer unit has been developed. This five-band equalizer distinguishes itself from other designs by utilizing transistors instead of integrated circuits and a power supply delivering a voltage range of +/- 24V DC. This configuration guarantees minimal distortion and expanded overload protection capabilities. Employing switch S1 facilitates isolating the equalizer, allowing the audio signal to pass through unaltered, either within or outside the equalizer’s operational mode.

Transistors

The core of this equalizer's functionality relies on seven BC550C transistors. These NPN bipolar junction transistors are commonly employed as switching and amplification devices. They contribute to the signal shaping and overall performance of the graphic equalizer. BC550C transistors are general-purpose devices, known for their reliability and moderate gain characteristics, suitable for a wide range of audio applications. Their use results in a greater headroom and reduced noise compared to IC solutions.

Circuit diagram

Part list