LM386 Audio Amplifier

13 Feb 2016

Greetings! My first post on Element, is a small audio amplifier using LM386 integrated.

For the design has been based on the one proposed in the datasheet (Gain = 200), some components and filters are added to the feed inlet (VALIM = 12V), the circuit used is this:

Here more photos of the PCB:

The final PCB with all componences looks like this:

Here one video of the circuit in action (video in spanish):

See more projects or info in my blog (in spanish)

Top Comments

DAB over 7 years ago

What is the bandwidth for the amplifier?

DAB
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jw0752 over 7 years ago

Hi Pedro,
This was a very nice project. It is really good that you are open to learning. I have learned a lot of new things by listening to michaelkellett as he always has good solid advice.
John
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mrchunckuee over 7 years ago in reply to michaelkellett

Thanks for the recommendations are useful for future designs
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michaelkellett over 7 years ago

if you do any more of this work the consider how to arrange the tracks so that the ground plane flows better. Look how far it is from VALIM-2 to X1-2 and how thin the ground connection gets at the top of the board. The ground connections to the pot have to share a long and tortuous path with the load current. The little bit of ground near C7 isn't doing anything useful.

For a low gain audio amp you may get away with this (although it might well have issues with CE level EMC susceptibility tests). For anything working at high frequencies it pays to make your ground planes better.

Hope this helps your next design.

MK
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mrchunckuee over 7 years ago in reply to nick123

Thanks! I haven't experimented with guitar amplifiers, but if i find something i share
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