Introduction
In this tutorial, we are making the “LM386 Acoustic Audio Amplifier Circuit”. Acoustic amplifiers are devices that are used with acoustic instruments to improve and magnify the sound generated by the instrument, often a guitar. These devices come in a variety of sizes and, depending on the type, may create varying degrees of volume.
In the making of this circuit, we use LM386 IC as our major component. There are a few advantages to using this IC. This IC accepts a supply voltage range of 3 to 15 volts. Also, a maximum analog voltage of 0.4V is possible. The voltage gain of the LM386 IC ranges from 26 to 46 dB. The speaker’s impedance is also 4 ohms. The IC has eight pins. So, before we start building the circuit, let’s go through the pin arrangement.
Pin Configuration of LM386
| Pin Number | Description |
| 1 | Pin 1 is there to set the gain. |
| 2 | Inverting input pin, usually grounded. |
| 3 | Non-inverting input pin to provide the audio signal |
| 4 | Ground pin |
| 5 | It gives the output. |
| 6 | It takes the Vcc |
| 7 | Bypass pin to connect decoupling capacitor. |
| 8 | Along with Pin 1, this pin also set the gain of the circuit. |
Hardware Required
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | Audio Amplifier IC | LM386 | 1 |
| 2. | Ceramic Capacitor | 0.01uF, 0.1uF | 1,1 |
| 3. | Electrolytic Capacitor | 10uF, 100uF | 2,1 |
| 4. | Resistor | 1KΩ, 10KΩ, 10Ω | 1,1,1 |
| 5. | Speaker | – | 1 |
| 6. | Potentiometer | 10KΩ | 2 |
| 7. | LED | – | 1 |
| 8. | 2-Pin Connector | – | 1 |
Circuit Diagram
Working Explanation
This circuit can be readily constructed with a few passive components; we need a potentiometer to change the volume, gain, and bass. Also, by using this variable resistor input audio will be sent to the non-inverting pin of the LM386 while the inverting pin is grounded. The Vcc supply may range from 5 to 12 volts is used, with the output biassing to half of the supply voltage.
The gain control variable resistor is wired between gain pins 1 and 8 of the LM386, while the bass control variable resistor is connected between the output and pin 1 of the LM386, with n/c open terminals. The existence of the power supply to the lm386 acoustic audio amplifier circuit is shown by the LED1.
Application and Uses
- These amplifiers are utilized in sound systems.
- These amplifiers may be found in a variety of musical instruments.
- Audio amplification is essential for signal transmission over long distances.
