Electronics > Projects, Designs, and Technical Stuff
Universal LM386 Audio Box
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jonovid:
Wow- the circuit shown in Mr Carlson's Lab video is somewhat like what Im trying to do here.  :-+
but with more gain range from the highist   to the low line level signals.
-anyway looking at your LM386 circuit

--- Quote ---Anytime the LM386 sounds extra gritty or full of AC hum and buzz, or AM radio, it's because the IC is oscillating around 13MHz. The RF bursts show up at higher volume and radiate from the speaker wiring.
--- End quote ---
now that is bad for an audio ic, - I may need a lot more RF suppression in my project.  ferrite beads.
interesting to see how you have resolved the output,  diode limiter,
& the use of a 1M pot.  -that I do not have in the right size for my project. 

--- Quote ---I kind of hate the IC because it is such a cheezy internal circuit, noisy distorted and goes back to 1976. It really needs an update. But it is convenient and OK for speech. Ali/eBay kits are $1.50 including IC, pot, pcb, DC jack etc. and hard to resist, although they are junk- have bad PCB layout and smallish 10k pot.
--- End quote ---

most pre assembled LM386 amp module's sold for arduino, have a lot missing in its circuit with only a 100uF on the output.   ::)

so I am stuck with a bag of cheap 4-to-15 volt LM386's off aliexpress, so the need make-do with this ic with its shortcomings.  :-[
as I often copy my more successful circuits in part or in whole when considering new projects.
the maximum gain of 200 for the LM386 with a 10k pot is somewhat inadequate for some of my uses, like dynamic microphones & tape heads.
so I found this npn audio transistor circuit that did the job when tested running off 4-to-6 volts.  :-/O
its one successful white noise generator when open circuit. but otherwise will do the job for now
however looking at the circuit shown in Mr Carlson's Lab video, I can see how some improvements can be made to my circuit
with a little more planning within the limits of a plastic case.   
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