Sunday, November 7, 2010

80W Power Amplifier based LM12

This is a very simple amplifier circuit based LM12. Although with a very simple design of schematic diagram, but this circuit can provide output power up to 80W. To get stereo output, make two pieces the same circuit and connect it to each output of the stereo tone control / pre-amp / mixer / equalizer or radio/mp3 player / ipad / dvd player / tv output.

Circuit diagram:

80W Power Audio Amplifier with LM12 circuit

PCB layout:

80W Power Audio Amplifier with LM12 circuit

LM12 Features:
There are important features included on LM12:

  • Input protection
  • Controlled turn on
  • Thermal limiting
  • Overvoltage shutdown
  • Output-current limiting
  • Dynamic safe-area protection

You may download the LM12 datasheet HERE

About Audio Amplifier
An audio amplifier is an electronic amplifier that amplifies low-power audio signals (signals composed primarily of frequencies between 20 - 20 000 Hz, the human range of hearing) to a level suitable for driving loudspeakers and is the final stage in a typical audio playback chain.

The preceding stages in such a chain are low power audio amplifiers which perform tasks like pre-amplification, equalization, tone control, mixing/effects, or audio sources like record players, CD players, and cassette players. Most audio amplifiers require these low-level inputs to adhere to line levels.

While the input signal to an audio amplifier may measure only a few hundred microwatts, its output may be tens, hundreds, or thousands of watts. More explanation about power audio amplifier can be found at

This is a video tutorial about how to a very simple audio amplifier based on the LM386 amplifier chip. It can be built for less than $20 (or might be less than $8 in some countries) and used to amplify any low level audio signal including a guitar, bass or mp3 player.

Watch the video:

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