Table of Contents
Mini Audio Amplifier with LM386 IC: Volume and Bass Boost Adjustment. The LM386 integrated circuit is widely used in audio projects due to its simplicity, versatility, and low power consumption. In this article, we present a project of a mini audio amplifier with volume adjustment and bass boost enhancement, ideal for applications such as portable speakers, DIY systems, and electronics learning.
Características do Projeto
- CI LM386: Low power audio amplifier.
- Power supply voltage: 5V to 12V (ideal for batteries or external power supply).
- Adjustable gain: From 50x to 200x, configured by external components.
- Volume control: Potentiometer integrated into the circuit.
- Bass Boost: Bass enhancement activated by a jumper and capacitor.
- Mono output: Compatible with speakers up to 1 to 10W RMS.
Schematic Mini Audio Amplifier with LM386 Bass Boost volume
BOM Mini Audio Amplifier with LM386 Bass Boost volume
Last update: 01/13/2025 21:08
| Parts | Value | Description | Quantity |
| Resistores 1/4W | |||
| P1 | 47k | Potentiometer | 1 |
| R1, R2, R3, R4 | 10K | Brown, black, orange, gold | 4 |
| R5 | 10 | Brown, black, black, gold | 1 |
| R6 | 1.2k | Brown, red, red, gold | 1 |
| R7 | 1K | Brown, black, red, gold | 1 |
| Capacitores | |||
| C1, C2, C3 | 10µF/16V | Electrolytic capacitor | 3 |
| C4 | 100n (104) | Film capacitor | 1 |
| C5 | 220µF/16V | Electrolytic capacitor | 1 |
| C6 | 33n (333) | Film capacitor | 1 |
| C7 | 100nF (104) | Ceramic capacitor | 1 |
| C8 | 1000µF/16V | Electrolytic capacitor | 1 |
| CN1 | IN2 (Input) | XH connector 2 pins 2.54mm | |
| CN2 | OUT (Output) | XH connector 2 pins 2.54mm | 1 |
| CN3 | DC2 (Power supply) | XH connector 2 pins 2.54mm | 1 |
| Semicondutores | |||
| IC1 | LM386 | DIL08 – Audio Amplifier | 1 |
| J1 | IN | JW-PJ-307-5 | 1 |
| J2 | DC1 | Jack DC | 1 |
| Diversos | |||
| LED1 | LED 3mm | 3mm LED | 1 |
| Soldering, Wires, PCB, Box, Power Supply | |||
Operation of the Circuit
- Signal Amplification Circuit Operation:
The LM386 IC amplifies the input signal connected to connector J1, stereo signal will be merged at connector CN1. The standard gain is set at 50 times, but can be increased up to 200 times by connecting jumper JP1. - Volume Control:
Potentiometer P1 regulates the signal level before amplification, allowing precise volume adjustments with logarithmic potentiometer simulation. - Bass Boost:
Jumper JP2 activates the bass boost feature, which uses capacitors C6 and R4 to enhance lower frequencies. - Filtering and Stability:
Capacitors like C7 and C8 ensure power filtering, reducing unwanted noise in the amplified signal. - Visual Indication:
LED1 lights up when the circuit is on, indicating correct operation.
Applications
This mini amplifier is ideal for:
- Portable speakers.
- Embedded systems with Arduino or Raspberry Pi.
- Signal amplification for bench testing.
- Educational projects in electronics.
Tips for Assembly:
- Use a well-filtered power source to avoid audio noise.
- Make sure the capacitors are connected in the correct polarity.
- For greater sound efficiency, connect a speaker with compatible impedance and power.
Conclusion:
The mini amplifier with LM386 IC is a practical and efficient solution for projects that require amplified audio with volume control and bass enhancement. With few external components, it offers excellent performance in various applications. Build this circuit and experience the versatility of the LM386!
Download the files, links, and notes
Download the PCB in Gerber + BOM + Centroid File + PDF + PNG
- BUY LM386 DIY kit
- Datasheet PDF IC Lm386 – Texas Instruments
- Datasheet PDF IC Lm386 – UNISONIC TECHNOLOGIES CO (UTC)
- Datasheet PDF IC Lm386 – JSMSEMI
- Datasheet PDF IC Lm386 – HGSEMI
- Datasheet PDF IC Lm386 – XBLW
- Datasheet PDF IC NJM386 – new japan radio co. ltd (JRC)
