The tone control is a type of equalization used to make specific pitches or “frequencies” in an audio signal softer or louder. A tone control circuit is an electronic circuit that consists of a network of filters that modify the signal before it is fed to speakers, headphones, or recording devices by way of an amplifier. It allows listeners to adjust the sound to their liking and compensate for recording deficiencies, hearing impairments, room acoustics, or shortcomings with playback equipment. For example, older people with hearing problems may want to increase the loudness of high pitch sounds they have difficulty hearing.
It can be used to adjust an audio signal during recording. For instance, if the acoustics of the recording site causes it to absorb some frequencies more than others, tone control can be used to amplify or “boost” the frequencies the room dampens. Here we design a tone control circuit using IC741 and other easily available components.
Hardware Required
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | IC | LM741 | 2 |
| 2. | Resistor | 330KΩ,10KΩ,680KΩ,1.8KΩ,3.3KΩ,270Ω | 1,4,1,2,2,1 |
| 3. | Variable Resistor | 500KΩ,100KΩ | 1,2 |
| 4. | Capacitor | 0.47uF,10nF,22uF,4.7nF,5.6nF,22nF,56nF, 1nF,100pF,4.7uF | Each one |
| 5. | Connecting Wires | – | – |
| 6. | Dual Power Supply | 15V | 1 |
Circuit Diagram
Working Explanation
As shown in the circuit, there two operational amplifier ICs are used. Here the first one pre-amplifies the audio input and the second stage operational amplifier gives tone-controlled audio output with amplification. These operational amplifier uses inverting input pin as an input. Now output signal from the first amplifier is split into two by the Baxendale circuit. Here this circuit provides bass, middle and treble tone controls over the audio signal. The output from this circuit is amplified by the second-stage amplifier. We have used a 15V dual power supply to bias this circuit.
Applications
Used in many sound systems: radios, portable music players, boom boxes, public address systems, and musical instrument amplifiers.
