LM386 configuration

tracecom

Joined Apr 16, 2010
3,944
I tried using a mp3 player and a 4Ω speaker (blastking YD10360PF) like you suggested.
I'm getting to much noise from the speaker when I raise the volume and gain pots.
I don't mind the low volume but I'd like a more clearer sound.
some possible reasons:
I'm using linear pots for volume and gain. I couldn't find log pots.
the speaker is 50 watt, 4 inch, 5 oz. to big maybe?
from the pics I posted: to much spacing between the components?
There is some distortion when the volume and gain pots are set to maximum. Try setting your MP3 player to maximum and backing off the volume and gain in the amp.

The linear pots are okay. They may be a little harder to adjust, but they don't contribute to the distortion.

I think that a smaller speaker would present less of a load on the LM386. I use a 2" 4 ohm speaker regularly with no distortion at normal small room volume.

If you are using a 9V battery, the amp's distortion will increase when the battery voltage drops. Try a new battery.

Here's a picture of my little amp that I use quite often in my old pickup truck to listen to my MP3 player.
 

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tubeguy

Joined Nov 3, 2012
1,157
I think that a smaller speaker would present less of a load on the LM386. I use a 2" 4 ohm speaker regularly with no distortion at normal small room volume.
Just a nit, but the diameter of the speaker doesn't really matter, more the impedance. :) I was wondering if the op has the speaker mounted in an enclosure. If not the front/back radiation 'meets' and cancels the sound, and very little sound is produced as the frequency drops. Very soft on the E, A, strings. :eek:
 

Thread Starter

Brogkul

Joined Mar 7, 2013
12
I build it on a perfboard. tested it with an MP3 player and the result was excellent. theres no noise anymore and its loud and clear enough to make me happy.
I haven't encased it yet. I'm planning on using a wooden box I purchased a while ago. once I set it up all together I'll post some pics.
thanks again for the answers and the recommendations.
thanks to tracecom. I used your design as an example to build my perfboard (my first).
 

tracecom

Joined Apr 16, 2010
3,944
I build it on a perfboard. tested it with an MP3 player and the result was excellent. theres no noise anymore and its loud and clear enough to make me happy.
I haven't encased it yet. I'm planning on using a wooden box I purchased a while ago. once I set it up all together I'll post some pics.
thanks again for the answers and the recommendations.
thanks to tracecom. I used your design as an example to build my perfboard (my first).
Good for you. I look forward to the pictures.
 

Thread Starter

Brogkul

Joined Mar 7, 2013
12
here is the final design.
I'm really happy with the outcome, I made some measurements to calculate the power output: 541mW.
I really appreciate the help I got on these forums.
'Till next time.
 

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wayneh

Joined Sep 9, 2010
17,496
Cool. Consider putting this into the "completed projects" area. I think you've done most of the work already, it just needs a little write-up.
 
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