Passive Tone Control

A passive tone control uses only resistors, capacitors, and potentiometers to adjust bass and treble. It does not require a power supply, but it can only attenuate frequencies (cut), not amplify them.

Circuit Diagram

Working Principle

The circuit works by diverting certain frequency components of the audio signal:

• Bass Cut: Capacitors block low frequencies, reducing bass.
• Treble Cut: Resistors and capacitors form a low-pass filter to reduce treble.

Since it’s passive, there is an overall signal loss, so the output is weaker than the input.

Applications

- Simple guitar amplifiers - Vintage radios - Low-cost audio equipment