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Questions tagged [lm386]

The LM386 is a "Low Voltage Audio Power Amplifier"

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Why can I hear a radio station when probing with oscilloscope? [duplicate]

I assembled this on a breadboard: and am hearing a faint buzzing sound... My first question is, what could be causing this sound? It does not go away if I connect VIN to ground. With or without VIN ...
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4 votes
2 answers
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Schematic review for an ultrasonic heterodyne mixer

I'm building a heterodyne ultrasonic bat detector with a mems microphine (Knowles SPU0410LR5H-QB) and the SA612 mixer. I have built it on a breadboard and it works. It has some hum and noise but I ...
Gos's user avatar
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LM386 Amplifier Mix Dual Audio Signals

I am trying to build an audio amplifier which will get input from an electret microphone and music signals from mobile using aux cable. I found a schematic diagram in the Circuit Digest website which ...
Kailash Kumaravel's user avatar
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2 answers
166 views

Can we place capacitors parallel to the speaker (30 ohm headphone) and aux jack?

I am working on an audio amplifier PCB circuit, where I have used LM386 as an amplifier, an aux jack for audio output, and a small speaker of headphones (30 ohm). I have two 220 uF molded and one 470 ...
Noor Hassan's user avatar
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1 answer
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Parasite cancelation on a LM386N amp

I have put together: an Raspberry Pi Pico that manages a keypad and a simple audio amp based on LM386N. The audio amp is connected via GP22 which provides PWM and plays the role of sound-audio ...
thermike's user avatar
2 votes
2 answers
410 views

Why is the LM386 so noisy when powered from wall?

I am using an LM386 to amplify an electret signal. Configuration for a gain of 200x is shown below. When powered from my bench power supply in quiet conditions, the output is around 4 mV (RMS). ...
broken.eggshell's user avatar
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3 answers
977 views

Volume control in LM386 Audio Amplifier

I am looking at making a simple audio amplifier as part of a school project im doing. One thing that it must do is have adjustable volume so this circuit seems like it will do the trick. To adjust the ...
Benjamin Collier's user avatar
3 votes
3 answers
1k views

What's the math behind the Zobel network on LM386 audio amplifier?

(Image source: Texas Instruments - LM386 datasheet) This is an 8 Ω speaker. I want the math on how they got 0.05 µF and 10 Ω.
ORLANIX's user avatar
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4 answers
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How can I use the same microphone for an amplifier and a mobile phone?

This is my first question on this forum, and I would like to say that I am learning electronics, and I am not an expert by any means. I am currently trying to realize a small project using a LM386 to ...
Miguel Hernández's user avatar
0 votes
1 answer
92 views

Why aren't my LEDs turning on while using Proteus?

I'm trying to simulate an audio vumeter, using an audio amplifier built with a LM386. However, when I connect the output of the signal to the input of one of the opamps (I'm using LM358), the outputs ...
Alexa Martínez's user avatar
8 votes
2 answers
847 views

How can LM386 follow a signal when it becomes negative?

Here is a picture from the datasheet of the LM386. Obviously, the input signal is swinging above and below the ground, but pin 4 is not connected to a negative supply. It is connected to the ground (...
MikeTeX's user avatar
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LM386 driving transformer going into oscillation

I have a transformer on the output of a LM386. The circuit works just fine with 42TU003-RC, but when I use any other transformer the circuit goes into osillation at ~350 kHz on the output of the LM386....
Electric Circuits And Such's user avatar
3 votes
2 answers
103 views

Why does LM386 datasheet indicate a recommended operation conditions of +/- 0.4V for Vinput, which is also the abs max rating of that input?

Why does the LM386 datasheet indicate a recommended operation conditions of +/- 0.4V for Vinput, which is also the abs max rating of that input? I thought that absolute maximum ratings should be ...
Jeff's user avatar
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1 vote
1 answer
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Electret microphone to speaker noise

I have been working on a circuit where part of the work involves an electret microphone that gets the input signal and outputs it through a speaker. It happens to have noise emanating from the speaker....
Waya Bryan's user avatar
1 vote
0 answers
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I am making a theremin-like circuit using a 555 timer and an LM386 amplifier chip. It’s currently not outputting any sound. Why is it not working?

This is the 555 timer circuit that I am using: This is the LM386 circuit I am using: I have connected the output of the 555 timer to the 10k potentiometer. If I connect the 555 timer part of the ...
Tara's user avatar
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1 vote
1 answer
371 views

How to remove low-level audio noise from an ATMEGA328p + LM386 circuit

I'm building an audio project with an ATMEGA328p using an LM386 as the amplifier and the Mozzi audio library. Power source is 4 AA batteries. I'm using an MCP1700 voltage regulator to drop the ...
cody blanchard's user avatar
10 votes
2 answers
2k views

LM386 amplifier circuit

I am building an audio amplifier with LM386 with a voltage supply of 5 V. The input signal is 50-250 mV. Can anybody tell me why there is a resistor and capacitor in series at the output? As the value ...
Mudassir Ahmad's user avatar
0 votes
2 answers
205 views

How to amplify audio signal made of two inputs?

I have made low-cost mosquito repellent, but I want to amplify the audio signal. The problem is, that in the source (https://electronicscheme.net/low-cost-mosquito-repellent/) the audio is made by ...
iltelko's user avatar
0 votes
0 answers
378 views

LM386 doesn't work in Proteus

I'm working on this project and I realized that the LM386 IC doesn't work in my Proteus application and the output is always zero. I tried another symbol I downloaded from the Internet too but none of ...
hamed mohammadi's user avatar
2 votes
0 answers
873 views

Active low pass filter built around an LM386

I have some theoretical electronics knowledge from uni, but when it comes to applying it in practice, things can get a little bit complicated. I've built simple stomp box, basically a piezo transducer ...
Jakub Mazur's user avatar
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127 views

Using diy lm386 preamp on standard commercial amp?

I have a small intercom-like device that has been siting around. It looks something like this. I suppose that inside is just a basic elect-mic and a button. Also i have an power amp which i used to ...
Milo Perovic's user avatar
0 votes
1 answer
91 views

Inaccurate voltage readings on an esp32 as opposed to multimeter

I am working on detecting the amplitude of a signal coming from a guitar pickup. I am using an esp32 and an LM386 module for amplifying the signal. I get quite stable readings with a multimeter, but ...
Arjuna Deva's user avatar
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1 answer
105 views

On the LM386 opamp Module, why I am getting an output without giving input

I am using an LM386 opamp Module from Amazon. I am powering it with a 5V input (just to power it, not intending to amplify anything at this point). Nevertheless a multimeter measures an amplified ...
Arjuna Deva's user avatar
2 votes
2 answers
707 views

10W speaker with LM386?

I have a simple question. I'm making an audio amplifier using the circuit given in the LM386 datasheet. According to the sheet, my IC can supply max 1W of output power and recommend load is 4 ohm. The ...
knight's user avatar
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8 votes
3 answers
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(How) does LM386 allow an input past its negative rail?

I am confused by the LM386. In the data sheet, multiple examples connect the inverting input directly to ground. To me, that feels weird. How can the IC amplify if the input goes below GND? The data ...
polwel's user avatar
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1 vote
1 answer
301 views

Difference in noise levels between inverting and non-inverting inputs of LM386

An article on Hackaday claims that the inverting input of LM386 is less noisy than the non-inverting one: We’ve also noticed, and we’re not alone, that the inverting input seems to be less noisy than ...
Kris's user avatar
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2 answers
120 views

FM modulation in FM transmitter

I'm using an LM386 for voice amplification. The transmitter transmits the signal from the tank circuit on the correct frequency but without voice. I'm a beginner and a hobbyist and I'm still trying to ...
titpoettt's user avatar
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2 answers
1k views

Electret microphone for ADC input

I'm currently working on a fun PCB project and have this circuit built that will input into an ATmega328P. What I'm looking for is what you guys think of this and if you think it will work. Does the ...
johnson8ryley's user avatar
2 votes
1 answer
355 views

LM386 circuit design questions

Initially I trawled posts and forums (initially to debug some noise, squeals, and oscillations on some LM386 circuits I built). I've synthesised all of that knowledge and re-approached this IC, ...
trippingonwires's user avatar
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1 answer
580 views

Using a computer mic with lm386

I'm working on a two way amplifier/intercom for my parents to use in the car because of road noise and hearing problems. I got a couple LM386n-4 and I've tried the circuit layout from here: http://www....
AndyD273's user avatar
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-1 votes
1 answer
229 views

Why is my LM386 reducing voltage and not amplifying it?

LM386 datasheet. I'm working with an 8-bit, R2R-ladder DAC that is connected to the LM386 that is then connected to an 8ohm/3W speaker. The output of the DAC is connected to pin 3 of the amplifier, ...
Fabian's user avatar
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0 votes
3 answers
470 views

How to overdrive a signal?

I am planning to build this circuit below as a electric guitar amplifier. Source And I also would like to add gain control overdrive channel to existing design. I have simulated this circuit on ...
Nabla's user avatar
  • 271
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1 answer
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LM386 LTspice simulation output problem

Source I am trying to simulate this circuit before setting it up on breadboard. I have downloaded this model for simulation, and set up the circuit. Transient simulation for vout: What am I missing ...
Nabla's user avatar
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2 votes
3 answers
5k views

How to build a low noise MIC preamp

I want to be able to talk on the microphone of my Headset A and send that signal out to the earphones of my Headset B. Something similar to what I show you on the image below. For that purpose, I ...
davidesp's user avatar
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-1 votes
2 answers
344 views

R-2R ladder connected to amplifier causes voltage to DECREASE

I'm working on a project and requires 4-bits of data from a micro-controller. I chose R to equal 1k ohms and the max V_out from the DAC (V_R-2R) without the amplifier measures around 1.6V and the ...
Fabian's user avatar
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2 votes
2 answers
401 views

What is the purpose of this jumper in this amplifier schematic or PCB?

Some time ago I bought a little amplifier kit on Banggood based on the LM386 chip. After soldering the kit I tested it, and it worked great, so I decided to buy a few more of these kits to incorporate ...
Marlon's user avatar
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1 vote
1 answer
824 views

Idea for a PC bios beep buzzer

Hi I want to make a buzzer for my PC motherboard. Similar things like this: https://boip.in/home/rajiekart-pc-motherboard-internal-speaker-bios-alarm-buzzer-1-pcs-pack?gclid=...
Ashok Das's user avatar
1 vote
3 answers
808 views

How does the LM386 work?

I am not an electrical engineer, but I am curious enough and my mind tells me to make a radio circuit. Now I am into it, so to make one, I need some components, but before that so that I can be a ...
SHikha Mittal's user avatar
1 vote
3 answers
617 views

What is making this LM386 circuit so distorted?

I found this circuit on a YouTube video and tried copying it down into a circuit for testing, but the audio that comes out of it is really low quality and distorted. I don't expect sterling quality ...
Michael Cordingley's user avatar
0 votes
2 answers
1k views

Condenser microphone + LM386 + Arduino

I found this simple circuit and I set it up with BCM-9767P, LM386N and tried to write out the values I get. The problem is that the values seem to be constant and don't change with the environment ...
treb's user avatar
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3 votes
5 answers
1k views

understanding input impedance theory

The key question is, what is the best or right way to modify input impedance? I am a self-teaching novice at electronics. I'm using the LM386 as a learning platform. Signal input comes from a "...
ChronoLogic's user avatar
1 vote
1 answer
423 views

Understanding LM386 amplifier component selection

I am a computer engineering student and I still struggle to understand electricity. I am doing an audio amplifier project and would like to understand the math behind why these capacitor/resistor ...
Jared M's user avatar
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3 votes
2 answers
514 views

Random Electrical noise LM386

I tried to make a microphone (condenser microphone) amplifier that powers a 0.5W 8 ohm speaker using the LM386, however I have been having random noise issues. Whenever the power is connected, the ...
Fleshy's user avatar
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1 vote
1 answer
444 views

Can I use one LM386 amplifier to drive 2 speakers(no stereo needed)?

Can I connect 2 speakers to the same output of the LM386 audio amplifier?
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0 votes
0 answers
681 views

Overheating LM386

I am still trying to build a simple audio amplifier using the LM386. I also found some older LM386 in my department, since my previous batch may be corrupted. Using this circuit I rebuilt it using a ...
v3xX's user avatar
  • 415
-1 votes
2 answers
965 views

Test defect audio amplifier LM386

Following this question I wanted to check if my amplifiers are faulty. I rebuilt the schematic in the datasheet (p.10 9.2.2) and slowly increased Vin. There was no change in output gain when ...
v3xX's user avatar
  • 415
3 votes
3 answers
2k views

Microphone with LM386

I am trying to build an audio amplifier circuit based on this design using an LM386 opamp. On the output side (pin5) an Arduino is connected constantly reading out the pin ...
v3xX's user avatar
  • 415
0 votes
1 answer
107 views

555 NOISE BUTTON/ OP AMP

I have this circuit from the image below that I am designing myself. part of this circuit is cut so 2 78xx is present. This circuit is being designed and tested in parts. This part of the circuit has ...
gabriel's user avatar
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0 votes
2 answers
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simple LM386 amplifier noise

I tried to make an audio amp based on LM386 but the output is noisy when the audio is playing. Here is my circuit schematic I built on a solderless protoboard: simulate this circuit – Schematic ...
warownia1's user avatar
  • 101
0 votes
2 answers
5k views

Simple FM Radio Receiver project

I've been making my own simple FM radio. I know it's not quite appropriate to make this stuff on breadboard, but if it works, I'll move in on the board and solder it. I wanted to ask why my radio is ...
MerryGR's user avatar
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