Questions tagged [lm386]
The LM386 is a "Low Voltage Audio Power Amplifier"
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1answer
46 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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0answers
26 views
Reduce Noise for Teensy Motor Shield with Audio Amps Design
I am currently working on a motor shield (2 layer PCB) for a Teensy 3.5 micro controller for a hobby RC car project. Both the shield and the MCU will be powered by a 2S LiPo battery. This is one of my ...
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1answer
145 views
Alternate to LM386 for 3.3V system
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
166 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
3
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0answers
233 views
LM386 guitar practice amp circuit not working, need help finding mistake
Im very new to electronics and I built this guitar amp circuit on a breadboard:
and it was working really nicely. Now Ive decided to put the circuit on a universal pcb which i'll use in the actual ...
3
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3answers
661 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 ...
0
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2answers
137 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, ...
0
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1answer
305 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
137 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, ...
2
votes
2answers
791 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
165 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
831 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 ...
2
votes
1answer
79 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
77 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? ...
1
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1answer
161 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 ...
0
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1answer
117 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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2answers
207 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
243 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
58 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 ...
3
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1answer
391 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 ...
6
votes
4answers
5k 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
349 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
178 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 ...
0
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1answer
193 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
115 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
2k 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
80 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
235 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 ...
0
votes
2answers
268 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 ...
-1
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2answers
542 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 ...
3
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2answers
1k 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 ...
3
votes
1answer
162 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 ...
3
votes
2answers
375 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 ...
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2answers
304 views
Designing of an audio amplifier using LM386 and a preamplifier
This is the circuit . But i am still getting acoustic howling. What can I do to prevent it dynamically. Also I want to increase the sensitivity to the extent that when I rub my fingers in front of the ...
0
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1answer
129 views
Invisible Earbuds [closed]
I just made a pair of invisible earbuds using this guide http://www.instructables.com/id/Make-Your-Invisible-Earphones/?ALLSTEPS everything works fine using 6mm x 6mm magnets that sit in my outer ear ...
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2answers
480 views
What causes periodic noise with LM386 amplifier
I am trying to use a LM386 to amplify an audio signal so that I can listen to it using a speaker. I am using the recommended circuit from the data sheet:
When I connect my audio source to the input, ...
0
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3answers
261 views
LM386 no output with input signal below 2V
I'm trying to implement volume control using a digital potentiometer (LM386) and audio amplifier (MCP4131). The way I have it setup, I'm outputting square wave audio signals out of a PWM pin on the ...
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0answers
223 views
question on “Intercom” circuit I am planing to build
I am using Voice Record Module to save messages and then play them to one from selected outputs ...some kind of weird intercom system.
My OA is LM386 [can only do 2 links but I'll post image relevant ...
3
votes
3answers
2k views
why do I get noise on the output of the LM386 when I connect speaker but not when I connect a resistor?
I recently made a circuit to test out LM386 audio amplifier for the first time on solderless board. I relied on the datasheet circuit shown below:
First I connected a 7.5ohm resistor at the output ...
0
votes
2answers
1k views
What is a good capacitance to use for a low pass and high pass filter?
First, I am using the minimum components circuit for the LM386
I am going to use the first circuit on this page. I am going to use a potentiometer in series with the circuit to give me variable ...
0
votes
1answer
711 views
What kind of speaker can be used with an LM386?
I am trying to use an LM386 to drive some speakers. I have both a 4Ω 4W speaker and 8Ω 1.5W speaker. Would I have to build a different circuit for each of these and would the LM386 be able to drive ...
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4answers
8k views
How to decrease distortion/noise of LM386 amplifier at max gain and volume?
From my previous question, I've made LM386 amplifier and it works better than LM1458 amplifier. I've added gain and bass boost in my LM386 amplifier.
How to decrease distortion/noise of LM386 ...
6
votes
2answers
2k views
What is the purpose of the 250uF capacitor in the LM386 circuit?
The basic amplification schematics shown in the LM386 datasheet shows a 250 uF capacitor in series with the output. I don't have any 250 uF, but I do have plenty of 470uF. If I understand correctly, ...
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2answers
428 views
How loud is a 0.25W speaker supposed to be?
I know this is a very broad question; I just want to know what I should be expecting from it. At the moment it's hooked up to an LM386-N3 op-amp outputting a 5V single rail square wave and it is ...
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1answer
104 views
Need transistor power amplifying stage scheme
i'm doing audio amplifier for my bachelors degree in physics. I have to simulate it all in Multisim. And i'm all out of ideas.
First i've used simple LM386 amp scheme, but it doesn't give enough power....
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1answer
176 views
Do I need to decouple an LM386 if it is run from a battery? [duplicate]
What I would like to do is to put an LM386 in my bass guitar so that I can plug my headphones directly into it for practice. The LM386 was my first choice because it can run off of a 9V battery and ...
-1
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2answers
790 views
Question regarding simple preamp+audio amplifier
simulate this circuit – Schematic created using CircuitLab
simulate this circuit
Hello,as you can see,I constructed a circuit which consists of an amplifier(first scheme) and a preamplifier(...
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2answers
231 views
Simple LM386 Circuit RC Branch Question
Please take a moment to checkout at the LM386 circuit below. The circuit comes directly from the LM386 specifications document:
My question revolves around the output branch consisting of the 0.05 ...
0
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2answers
524 views
Feedback op-amp voltage regulator help
I have made a voltage regulator:
simulate this circuit – Schematic created using CircuitLab
And here is the zener circuit:
simulate this circuit
I have already tried to charge a device ...
0
votes
1answer
730 views
LM386 noise when using 5v power supply
I'm using LM386 with my guitar and currently I power it with 9v battery but now I want to switch to 5v power supply because I don't want to use a battery.
I want to use a 5v usb wall charger + ...
