Mini Audio Amplifier with LM386 IC: Bass Boost, Configurable Gain, and Electret Microphone. The presented circuit uses the LM386 IC, a low-power audio amplifier widely used for its simplicity and efficiency. This project is ideal for applications like portable speakers, DIY systems, and learning electronics. The assembly uses SMD components, making the circuit compact and efficient.
Project Features
- Main IC: LM386
- Power Supply Voltage: 4.5V to 12V
- Adjustable Gain: Configurations of 50x or 200x
- Volume Control: Integrated potentiometer
- Bass Boost: Activated by a jumper
- Input: P2 connector (3.5 mm) or electret microphone
- Mono Output: Compatible with 1 to 10W RMS speakers
Schematic LM386 mini amplifier bass boost volume microphone
Circuit Operation
Signal Amplification
The LM386 amplifies the signal received through the P2 connector or microphone. The default gain is 50x, which can be increased to 200x by connecting a capacitor between pins 1 and 8 of the IC.
Volume Control
The potentiometer adjusts the signal level before amplification, allowing precise volume control.
Bass Boost
The bass boost feature is activated by connecting a jumper that uses a capacitor and resistor (C6 and R4) to enhance low frequencies.
Filtering and Stability
Capacitors like C7 (100nF) and C8 (220µF) ensure power supply filtering, reducing noise in the audio output.
Schematic Overview
- The schematic includes:
- Input via P2 connector or electret microphone
- Volume adjustment potentiometer (P1)
- Optional gain configuration via external capacitor
- Power indicator LED
Tips
- Use a well-filtered power supply to avoid noise.
- Ensure correct polarity of electrolytic capacitors.
- Use speakers compatible with the circuit’s power.
Applications, This mini amplifier combines simplicity and functionality, making it an excellent choice for learning or creating practical audio projects.
- Portable speaker systems
- Embedded systems with Arduino or Raspberry Pi
- Educational electronics projects
- Portable speakers.
- Embedded systems with Arduino or Raspberry Pi.
- Educational projects in electronics.
- This mini amplifier combines simplicity and functionality, being an exceptional choice for those looking to learn or create practical projects in audio.
- The LM386 is an integrated circuit widely used in audio applications due to its simplicity, efficiency, and low power consumption. Its most common applications include:
- Portable speakers: amplifies audio signals for small speakers, ideal for battery-powered devices.
- AM/FM radios: Used as an audio amplifier to improve sound quality on radios.
- Headphones and intercoms: acts as a driver for headphones or simple communication systems.
- Warning and alarm systems: amplifies sound signals in notification and security systems.
- Computers and multimedia devices: used in sound systems for laptops, desktops, and small multimedia devices.
- Electronic toys: amplifies sounds in toys that have audio output[5][6].
- DIY and educational projects: popular with hobbyists and students due to its ease of use.
- Microphones and voice recording: amplifies signals picked up by microphones, such as in recording or communication systems.
BOM LM386 mini amplifier bass boost volume microphone
Last update: 19/01/2025 21:41
| Componente | Valor | Descrição | Quantidade |
|---|---|---|---|
| Capacitors | |||
| C1, C2, C3, C9, C10 | 10uF | C0805 — SMD Capacitor | 5 |
| C4, C7 | 100nF | C0603 — Capacitor SMD | 2 |
| C5, C8 | 220uF | Electrolytic SMD Capacitor 6.3XL7.7MM | 2 |
| C6 | 33n | C0603 — SMD Capacitor | 1 |
| CN1 | IN2 (Aux Input) | XH 2.54 mm Connector (2 pins) | 1 |
| CN2 | OUT (Audio Output) | XH 2.54 mm Connector (2 pins) | 1 |
| CN3 | DC (Power Supply) | XH 2.54 mm Connector (2 pins) | 1 |
| Semiconductors | |||
| IC1 | LM386 | DIL08 Audio Amplifier IC | 1 |
| Miscellaneous | |||
| J1 | PJ-320B-SMT | Audio Connector (3.5 mm SMD) | 1 |
| J3 | MIC (MIC Jumper) | SJ — Jumper SMD | 1 |
| J4 | GAIN (Gain Jumper) | SJ — Jumper SMD | 1 |
| J5 | BASS (Bass Boost Jumper) | SJ — Jumper SMD | 1 |
| LED1 | LED 0603 | LED0603 — Red LED | 1 |
| P1 | 50K (503) | RK097 — Single potentiometer | 1 |
| Resistors 1/4W | |||
| R1, R2, R3, R4 | 10K (103) | R0603 — SMD Resistor | 4 |
| R5 | 10 (10R) | R0805 — SMD Resistor | 1 |
| R6 | 1.2k (122) | R0603 — SMD Resistor | 1 |
| R7 | 560 (561) | R0603 — SMD Resistor | 1 |
| R8, R9, R10 | 4.7K (473) | R0603 — SMD Resistor | 3 |
| Soldering, Wires, PCB, Box, Power Supply | |||
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)
