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Published on 08 Oct 2014 | over 2 years ago

Video demonstrates the assembly of an LM386 audio amplifier circuit. The LM386 is a great small scale audio amplifier, but selecting and connecting the right combination of resistors and capacitors, routing the numerous ground connections, etc., so that its output sounds even halfway decent is often quite a challenge. This video follows a schematic that I've developed after much trial and error. A professional audio engineer, etc., would likely be able to construct a circuit that sounds even better. I offer this video as a starting point for those interested in the LM386. It provides one with a circuit that at least doesn't start out with a mountain of strange crackles, pops, distortion, RF interference, etc. Definitely let me know if you build the circuit and later discover ways to modify and/or improve it so as to achieve an even better sound quality. I'm always interested in learning from others.

Parts List:
power supply (5V to 15V DC)
100uf capacitor (used for power supply decoupling)
1/8 stereo or mono audio jack (fits standard mp3/mp4 players)
LM386N - 3 (purchase a quality chip from a reputable company)
220 to 1000uf capacitor (between amp output and speaker)
470pf capacitor (used to reduce RF interference)
10uf capacitors (x2) (gain and bypass)
0.1uf capacitors (x3) polyester tends to sound better than ceramic
10 ohm resistor
10K resistor
8 ohm speaker (1 watt minimum)
standard hookup wire
---resistors should be rated for at least 1/4 watt (a higher wattage rating is fine)
---capacitors should be rated for 2 to 3 times the amount of voltage one expects them to 'see', e.g., if the circuit is powered with 9V, then one would want to use capacitors rated for 18 or more volts

Audio tracks used in this video were provided royalty free by Youtube.

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