Baxandall Treble and Bass Practical Circuit Project

This is a practical Baxandall circuit example that you can make and will work well for stringed instruments such as guitar or ukulele. I call it "When I’m cleaning windows..." This is a different circuit configuration example, which minimizes the component count to the absolute minimum, hence cash-strapped students and hobbyists will love to make it. This is one of my oldest and favourite circuits that I have made many times and has worked well for me.

The LM324 IC is a quad operational amplifier package that is internally frequency compensated, and the input bias currents are temperature compensated as well. It has DC voltage gain of up to 100 dB, and bandwidth of 1 MHz. It can operate on split-rail power supply, or single rail supply providing the non-inverting input bias is at mid rail, achieved by utilising a simple resistor potential divider.

If you are going to feed the output of the Baxandall circuit to a domestic power amplifier through its auxiliary RCA inputs, then I have matched the impedance to 47 kΩ for modern amps. This should work well for modern practical applications.

Component List

Power Supply

If you are using a split-rail power supply, then this circuit makes sure you connect it properly as many hobbyists and students tend to trip up here. Usually engineers may employ voltage regulator ICs to provide the ±12 V split-rails, which you then introduce to the IC circuit in the manner shown in the above diagram.

Power Supply Component List