Questions tagged [lm386]

The LM386 is a "Low Voltage Audio Power Amplifier"

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76 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 ...
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2answers
56 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 ...
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1answer
68 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 ...
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1answer
51 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 ...
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2answers
79 views

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 ...
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2answers
109 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 ...
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35 views

Analog VU meter with 1 watt lm386 amp

I am building a small cigar box speaker with an lm386 and think it would be cool to have a working analog VU meter on the front. There are obviously a lot of cheap ones from China which I would be ...
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1answer
114 views

LM386L does not amplify the microphone signal

I've encountered a problem. I recently bought a condenser microphone and I wanted to have some fun, so that if I said something into the microphone, I'd hear myself in the small 8 Ohm 0.5W speaker. I ...
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1answer
68 views

Powering up second LM386N results in screaming squeal

So I'm definitely a newcomer in the audio electronics realm but I've been really digging into circuits and experimenting with sounds. I've been focusing alot of time working through examples that use ...
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2answers
642 views

Why is the output signal of my amplifier heavily distorted?

I checked the circuit 1 million times. I got it from a website. Everything is correctly connected. The sound is loud, but it is very distorted. I use a 9 V battery. Where is the problem? :( ...
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2answers
2k views

LM358n versus LM386 for audio amp

Here's the pinout diagram for an LM358 Here's the pinout diagram for the LM386: Here's a very basic circuit showing an audio amplifier created using an LM386: If I built the equivalent circuit ...
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2answers
96 views

LM386 speaker distorts

I've built an amplifier with an lm386 but when I connect a speaker (8ohm) to the output I get a very distorted signal. The problem appears only when the speaker is connected. If I connect an external ...
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260 views

Can I remove zobel network in LM386 circuit? [duplicate]

What happens if I omit this part? Actually I don't have 10om resistor and I want to know is there any alternative? ps: I know what is a zobel network. I want to know what happens if I omit it.
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529 views

Volume control for LM386

For some context, see my earlier question: Ceramic capacitor value for an LM386N project What I learned is that the 10k potentiometer on pin 3 (Vin) forms a voltage divider. When I carefully dial it, ...
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1answer
192 views

Ceramic capacitor value for an LM386N project

I am adding an LM386 to a music project and follow the guidelines in the datasheet: My Vs is 4.7 V. My Vin comes straight from a 12 bit DAC of a Cortex M3 MCU and goes from 0 to 3.3 V. Pin 7 is ...
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1answer
88 views

Using an LM386 with input and output transformers for isolation from power supply

The LM386 TI applications notes page 11 show an amplifier. Would like to use this chip with complete isolation of the output speaker and with the addition of an isolated input speaker. Am using ...
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2answers
713 views

LM386 motorboating that goes away with a resistor in parallel with the bypass capacitor on pin 7

I'm building a simple amplifier around a LM386. The circuit I'm using is this: The input is on pin 1 of the connector and is a square wave coming from a digital pin on a NodeMCU devboard. When I ...
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78 views

Portable Guitar Amp - Distortion, Volume & GND

I have tried following the given schematic There are 3 things I am unsure of (what I tried): The Volume 5k Potentiometer: I have tried adding a volume control to the schematic by placing the ...
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1answer
258 views

Non-inverting op amp problem

I have problem with an lm386 op amp in an non-inverting configuration. For the resistors, I take two equal resistors so i set a gain of 2. When i put a signal of 3.3 volts on the non-inverting pin, i ...
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1answer
565 views

Alternate to LM386 for 3.3V system [closed]

I'm trying control the volume of a small speaker (8Ω, 1/4W) in a 3.3V system using a potentiometer wheel (10kΩ). I've done this in the past using an LM386 in 5V systems, but the project I'...
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2answers
346 views

What happened with this LM386 Amplifier Output

yellow channel is from lm386 amp 20 times gain my circuit is from the lm386 datasheet with 16 V source, what i amplify is 40khz arduino pwm output, is there any explanation why this happened, thanks
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0answers
664 views

LM386 guitar practice amp circuit not working, need help finding mistake

I'm very new to electronics and I built this guitar amp circuit on a breadboard: and it was working really nicely. Now I've decided to put the circuit on a universal PCB which I'll use in the actual ...
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3answers
2k views

where to add gain and volume controls to LM386 guitar amp circuit?

Im trying to make a super simple guitar amp. heres the circuit using an LM386 operational amplifier: What exactly would affect gain but not volume, and volume but not gain? In the example circuit on ...
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2answers
207 views

Breadboard 9V Output vs 9V Battery

I've put together an lm386 audio amplifier circuit as shown in the image below. The volume was good when hooked up to the 9V output on my trainers breadboard, but when I hooked it up to a 9V battery, ...
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1answer
677 views

distortion with lm386 in parallel

I'm trying to make a decent audio amplifier using two lm386 wired in parallel. I used Jericho Uno's schematic (below) as a guide (link to video). My circuit looks pretty similar, but I wanted to ...
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1answer
194 views

whats up with this op-amp circuit? [closed]

Came across a few circuit components and I thought I'd have a little fun. I don't understand what's happening though. I implemented this circuit. The only differences were: I didn't have a .1uF cap, ...
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2answers
1k views

LM386 audio amplifier with push-pull output

I am trying to make a simple audio amplifier using an LM386 audio amplifier and a class AB amplifier push-pull output stage. Since I couldn't find something that explicitly combines the two (LM386 for ...
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2answers
216 views

What is the use of R5, C4, C2, R6, R5, D1 in the below amplitude modulation circuit?

the project is taken from this website for my college project http://www.instructables.com/id/Modulating-Audio-on-a-LED/ I think I have figured out function of few components but still need ...
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4answers
2k views

What is the role of these capacitors?

I was reading about op-amps and found this schematic. What is the role of those capacitors? Lets call them: 10uF - Cap A 250uF - Cap B 0.05uF - Cap C As of now, capacitor positioning and ...
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1answer
98 views

Where does my negative input voltage come from? [closed]

I'm a bit confused about the concept of an input ground for an op Amp. Let's say I'm amplifying the output from a 555 timer ic. I assume the output pin from the 555 is my positive input but what is a ...
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0answers
82 views

Problem with Simulation Results VS Tested Results for a signal

For the circuit shown i am having some trouble wondering why my tested signal looks like this (i understand that it could be clipping) but when i measure my circuit in the simulation it is correct? ...
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1answer
284 views

Please review my schematic design

This is my first design, a 4-Bit stereo DAC with LM386 amplifier. I'm using it to interface with my FPGA eval board which doesn't have any audio connector. My board uses a 2x6 'PMOD' connector. My ...
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1answer
144 views

Unsure of how to find the equivalent resistance of the following circuit due to the input resistance of the LM386 amp

My questions: How do i find the voltage across R3 for diagram 1? Do i have to take into account the input impedance of the LM386 amp (The second amp in the circuit schematics) or can i ignore it and ...
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241 views

UPDATED:Not understanding my output wave when using the LM386 amp

i am trying to create an analogue wave so that an audio signal can be played. Using PWM,(i.e. converting a square wave to an analogue signal hence need to use high pass then low pass filter before amp)...
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2answers
421 views

Not understanding aspects of the LM386 amp

For the following LM386 amp i have a couple of questions. Is C3 and R1 a low pass filter and if so how do i calculate the cutoff frequency for it? I.e. do i have to take the impedance of C2 into ...
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1answer
69 views

Searching for known subcircuits

I want to solve this exercise in the figure below.The question is "Recognise as many known Sub-circuits as you can in LM386 circuit".I tried it and found only that the transistor down and in the left ...
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1answer
759 views

LM386 Amplifier not amplifying

Long time lurker and relativly new to electrical engineering but this is the first time I've had a question so I just made an account. I would also like to start off by saying that I tried to follow ...
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4answers
8k views

Is a minimum of 1000µF capacitance needed between an lm386's output and a speaker and if so why?

In this video explaining how to make an audio amplifier, the narrator warns Don’t be misled by crappy schematics…with low values like 100 µF. You want to use at least 1000 µF [between the LM386's ...
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2answers
553 views

Driving LM386 with signal referenced to virtual ground

I'm working with a chip that outputs audio signals to headphones that are referenced to a virtual ground. Since I'm connecting the audio signal to a speaker instead of headphones, I'd like to ...
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1answer
318 views

Audio Mixing Circuit

So I'm working on a audio mixing circuit, and based on some research I settled on the following circuit: My question is whether or not the circuit will work as intended. I feel that the process of ...
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1answer
275 views

Best circuit to play music in car, using ISO 10487

instead of using a radio, I want to install a Raspberry Pi 3 with my own features in the 2Din Slot, so I have to make my own circuit to play audio. I tried with the following modules based in LM386 ...
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1answer
126 views

Lm386 audio amplier - lyrics not audible [closed]

I am trying to amplify the music signal coming from a phone using an LM386 module for a 8ohm 3W speaker using a 5V supply,but when I connect it to the source,it amplifies a portion of the music,not ...
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3answers
3k views

LM741 not amplifying

I used LM386 to amplify but its minimum 20x gain is to much for me use because my signal is maximum +-0.5v ac , riding 1V dc . this is my circuit. I am seeing a signal on scope but I cant hear ...
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1answer
112 views

Why is the LM386N-4 power rated @ 32Ω load, when the other variants are rated @ 8Ω? How can I find an appropriate speaker?

I'm trying to build an LM386 amplifier, but when looking at the datasheet to select the appropriate chip, I noticed the LM386N-4's power rating is based on a 32\$\Omega\$ load, while the -1 and -3 ...
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1answer
354 views

amplifying audio lm386 dumps negative part?

I am amplifying and audio signal with ac levels of around +-0.3V. This signal also has DC level of 1.2V I used 2 DC block capcitors because I saw the input should be ground referenced. The output of ...
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2answers
568 views

calculating speaker inductive

I am using an 8ohm ,0.5w speaker like this BMS16-16 . I also have LM386 which suggest to use a 10 ohm resistor in seris with a 0.05micro capcitor .I am trying to understand how this together is ...
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1k views

LM386 high frequency oscillation noise at Vs

I'm having trouble to understand why this is happening when I power my LM386 on a 9V battery with no load. The schematic is the basic application from the LM386 datasheet with the gain of 20 but ...
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2answers
2k views

LM386 gain-adjust bypass capacitor

In the LM386 datasheet it's stated that "If a capacitor is put from pin 1 to 8, bypassing the 1.35 kΩ resistor, the gain will go up to 200 (46 dB)". I don't understand how this capacitor could bypass ...
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1answer
203 views

Two different circuits not working on same power supply.?

I have designed a SIM900 circuit on a zero pcb board for testing purpose. It is working fine. In my application I need to make a call and then talk to the other person on call. So I have used PIC MCU ...
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2answers
972 views

What limits length of wire connecting audio amplifier to speaker?

Let's say I have LM386 or some other audio amplifier. What determines the length, resistance, capacitance and inductance (if L C parameters matter) of the conductor that carries the output of the ...