Troubleshooting LM386 Amplifier Noise: Capacitor Value and Behavior Explained

  • Thread starter Thread starter miroku
  • Start date Start date
  • Tags Tags
    Amplifier
AI Thread Summary
The LM386 amplifier can produce significant noise at the output, which can be mitigated by adding a capacitor, with a 47uF value being particularly effective. Other capacitor values may not yield the same noise reduction, leading to questions about their behavior. The LM386 is a power amplifier and should not be treated like an operational amplifier; it requires specific connections and configurations. Implementing a Zobel network may also help improve performance and reduce noise. Understanding the proper usage as outlined in the datasheet is crucial for optimal results.
miroku
Messages
2
Reaction score
0
hi guys,
i'm doing the testing amplifier for my DIY project,
and i using LM386 IC, i found that is a lot of noise at the output.
i saw an example putting a capacitor at the output to reduce the noise, it work!
the value of capacitor is 47uF. it not work well for other value capacitor.
But i not sure why behaviors like that? help please...
 

Attachments

  • lm_386.png
    lm_386.png
    1.5 KB · Views: 493
Last edited:
Engineering news on Phys.org
miroku said:
hi guys,
i'm doing the testing amplifier for my DIY project,
and i using LM386 IC, i found that is a lot of noise at the output.
i saw an example putting a capacitor at the output to reduce the noise, it work!
the value of capacitor is 47uF. it not work well for other value capacitor.
But i not sure why behaviors like that? help please...

The LM386 is not an opamp. It is a power amp, and you do not connect feedback around it like it was an opamp. Download the datasheet from National Semiconductor's website to see how it should be used.
 
Needs a zobell (spelling?) network.
 

Thread 'Underwater piezoelectric sensor array receive sensitivity'

Hi all I have some confusion about piezoelectrical sensors combination. If i have three acoustic piezoelectrical sensors (with same receive sensitivity in dB ref V/1uPa) placed at specific distance, these sensors receive acoustic signal from a sound source placed at far field distance (Plane Wave) and from broadside. I receive output of these sensors through individual preamplifiers, add them through hardware like summer circuit adder or in software after digitization and in this way got an...
View full post »

Thread 'Following up on the recent thread about Earth Resistance measurements'

I have recently moved into a new (rather ancient) house and had a few trips of my Residual Current breaker. I dug out my old Socket tester which tell me the three pins are correct. But then the Red warning light tells me my socket(s) fail the loop test. I never had this before but my last house had an overhead supply with no Earth from the company. The tester said "get this checked" and the man said the (high but not ridiculous) earth resistance was acceptable. I stuck a new copper earth...
View full post »

Thread 'Question about bonding ground and neutral'

I am not an electrical engineering student, but a lowly apprentice electrician. I learn both on the job and also take classes for my apprenticeship. I recently wired my first transformer and I understand that the neutral and ground are bonded together in the transformer or in the service. What I don't understand is, if the neutral is a current carrying conductor, which is then bonded to the ground conductor, why does current only flow back to its source and not on the ground path...
View full post »

Similar threads

DC-DC conv. Ripple affecting Speech Recognition - Capacitance multiplier
Replies
22
Views
2K
Heavy Amplifier Circuit Oscillation Happened
Replies
3
Views
2K
How to make an audio processing device for noise reduction ?
Replies
3
Views
2K
Understanding Capacitor Behavior for Noise Filtering?
Replies
15
Views
4K
Amplifier for electret microphone
Replies
34
Views
10K
PCB design and schematic for a half bridge power amplifier
Replies
8
Views
3K
Want to build a simple audio filter
Replies
3
Views
2K
What dominates the high-freq. behavior of a CS-amplifier?
Replies
1
Views
1K
How Can I Achieve Low-Noise Amplification of 1nA to 1V?
Replies
46
Views
17K
Available Noise Power and Amplifiers
Replies
1
Views
2K

Hot Threads

Recent Insights

Back
Top