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LM386 audio amplifier stereo circuit diagram and PCB. This is an audio amplifier with 2 LM386 integrated circuits. Basically, it deals with the use of 2 amplifiers, as in another article posted at a time ago. But this time it includes a printed circuit board for stereo version, in addition to power supply. The circuit operates with power supply or batteries of 6 to 12 volts. The best performance will be when using a 12V power supply and 8 Ohms speakers.
The operation of the circuit is simple and based on the LM386, responsible for the amplification, the stereo audio signal is coupled by the capacitors C5 and C11, the stereo potentiometer P1, is used to adjust the volume.
The components attached to pins 1 and 8 control the gain:
- No component: Gain = 20.
- 10μF Capacitor (Jumper on R2 and R4): Gain = 200
- 10μF Capacitor and 1.5K Resistor: Gain = 50
The output is coupled via 470μF Capacitor, if you want to use with headphones add resistors from 100 to 220 Ohms to 1Watt in series with the output.
The LM386M-1 and LM386MX-1 are power amplifiers designed for use in low voltage consumer applications. The gain is internally set to 20 to keep external part count low, but the addition of an external resistor and capacitor between pins 1 and 8 will increase the gain to any value from 20 to 200.
The inputs are ground referenced while the output automatically biases to one-half the supply voltage. The quiescent power drain is only 24 mW when operating from a 6-V supply, making the LM386M-1 and LM386MX-1 ideal for battery operation.
- Battery Operation
- Minimum External Parts
- Wide Supply Voltage Range: 4 V–12 V or 5 V–18 V
- Low Quiescent Current Drain: 4 mA
- Voltage Gains from 20 to 200
- Ground-Referenced Input
- Self-Centering Output Quiescent Voltage
- Low Distortion: 0.2% (AV = 20, VS = 6 V, RL = 8 Ω, PO = 125 mW, f = 1 kHz)
- Available in 8-Pin MSOP Package
Some names found for this IC – LM386 audio amplifier stereo circuit diagram
| Código | Maximum voltage in VDC | Maximum power in mW | Package |
|---|---|---|---|
| LM386N-1 LM386N-2 LM386N-3 | 15 | 700 | PDIP (8) |
| LM386N-4 | 22 | 1000 | PDIP (8 |
| LM386N | 15 | 700 | PDIP (8 |
| LM386M | 15 | 325 | SOIC (8) |
| LM386MM-1 | 15 | 325 | SOIC (8) |
| M386MX-1 | 15 | 325 | SOIC (8) |
| LM386MMX-1 | 15 | 325 | VSSOP (8) |
Schematic of the audio amplifier LM 386 stereo
Printed Circuit Board PCB for mounting the LM386N audio amplifier stereo circuit diagram
BOM for assembly lm386 stereo audio amplifier
| Part | Value |
| Resistors 1/4 Watt 5% | |
| R1 | 560 – Green, Blue, Brown, Gold |
| R2, R4 | 1K – Brown, Black, Red, Gold |
| R3, R5 | 10 – Brown, Black, Black, Gold |
| P1 | 10K – Double Potentiometer |
| Capacitors |
|
| C1 | 2200µF/ 16V — Polarized Electrolytic Capacitor |
| C2, C8, C14 | 100nF — 100n, 104, .1, 0.1 — Ceramic or Polyester Capacitor |
| C3, C9 | 100µF/ 16V — Polarized Electrolytic Capacitor |
| C4, C10 | 10µF/16V — Polarized Electrolytic Capacitor |
| C5, C11 | 4.7µF/16V — Polarized Electrolytic Capacitor |
| C6, C12 | 470µF/16V — Polarized Electrolytic Capacitor |
| C7, C13 | 47nF – 473, 47n, 0.047 – Ceramic or Polyester Capacitor |
| Semiconductors | |
| D1, D2, D3, D4 | 1N4004 or equivalent – Semiconductor diode |
| IC1, IC2 | LM386N – Audio amplifier integrated circuit |
| LED1 | Led Vermelho 5 mm |
| Connectors and their functions | |
| CN1 (AC) | Terminal block 2 pin 5.08 mm — Connector to connect the transformer. |
| CN2 (IN) | 3-pin 2.54 mm connector JST-XH-03 – Audio input connector |
| CN3 (OUT) | Terminal block 2 pin 5.08 mm – Audio Output Connector |
| Miscellaneous | |
| TR1 | 6 to 9 Volts/ 500mA Transformer |
| Solder, Wires, PCB, Box, Knob potentiometer, etc. | |
Download PDF files for assembling the stereo amplifier with LM386: LM386 Datasheet, PCB, Schematic, Component Layout and Silk Screen
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C1 is 16V? really?
Hello smaug, yes, 16v or 25v.
Hello, is there a RIAA preamp circuit for turntables without volume adjustments, etc?
Hello L’Illuminato Alternativo
https://xtronic.org/search/?q=riaa
Hi Tony, are You still busy with electronics?
Can I ask You a question about the LM386 amplifier?
Hello Mister X
Hi Toni, this circuit is exactly what what I’ve been searching for, small and simple. Unfortunately I cannot link to download the actual size PCB foil layout (Not Found Error 404). Is there any way to get that download? Any assistance from you or anyone who might be reading this would be greatly appreciated.
Much thanks.
Hello Geddes
https://www.dropbox.com/s/ycyav2rrownhqh4/Amplificador_Lm386_estereo_te1.com.br.zip?dl=1
Can I just remove the rectifier circuit on the left side of the PCB and add a DC input of 12v?
https://plus.google.com/u/0/photos/101112800394772849168/album/6404807513444186497/6404807512582091106?authkey=CMbI–Hb9aveKg
Hello Hackbox
Good job!
Can I add your photos to the article?
pregunto otra ves que tipo de transformador es, porque no se consigue de 9.6 volt, si no de 6 o 9 volt y si es encapsulado saludos desde venezuela
que tipo de transformador es encapsulado o normal, saludos