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LM386 voice audio power amplifier circuit design project

Using LM386 voice audio power amplifier circuit designed for use in low voltage consumer applications can be designed a very simple voice amplifier with variable gain and volume control.
The gain of this LM386 voice audio power amplifier circuit is internally set to 20 to keep external part count low, but the addition of an external resistor and capacitor between pins 1 and 8 will increase the gain to any value from 20 to 200.
The quiescent power drain is only 24 milliwatts when operating from a 6 volt supply, making the LM386 ideal for battery operation.
The device presented in this schematic needs a 9 volts DC power supply and a 8 ohms impedance speaker.

Electronic Circuits: 
Audio Circuits
Circuit Diagram: 
LM386 voice audio power amplifier circuit design project

Comments

Submitted by Philip on Sun, 10/26/2014 - 17:41.
Hello All, How does one add a second speaker to this? It's for a 'four' type rowing boat. Best wishes Philip

Submitted by Eltech on Sun, 10/26/2014 - 20:22.
Hello, You need just a second speaker? or you need to use this circuit as a two way intercom? If you need just a second speaker... a very simple way to do that is to replace the 8 ohm speaker with two 4 ohms connected in series.

Submitted by Philip on Sun, 10/26/2014 - 22:05.
That is quite a sensible idea! I thought most speakers were 8 ohm. The amp would be in a rowing boat. The cox at the stern, the 1st speaker 5ft away and the 2nd another 5ft away from that. It's just an amp; one mic, two speakers.

Submitted by Anonymous on Thu, 05/19/2016 - 14:40.
What Chip Is U1?

Submitted by Eltech on Sun, 02/12/2017 - 20:09.
LM386, Low Voltage Audio Power Amplifier