Many electronic projects require the use of a small audio amplifier. Be it a radio transceiver, a digital voice recorder, or an intercom, they all call for an audio amp that is small, cheap, and has enough power to provide adequate loudness to fill a room, without pretending to serve a disco! About one Watt RMS seems to be a convenient size, and this is also about the highest power that a simple amplifier fed from 12V can put into an 8 Ohm speaker.
LM386 Amplifiers – [Link]
This project is a Class-A Audio Amplifier based on 2SA1943 and 2SC5200 complimentary transistor pairs. This Super Class-A Amplifier is fully running at a bias of about 1.65A @ 35V, which it resulting in about 58W of continuous dissipation per transistor in the output stage. In this condition, you can highly imagine that the heat sink runs in a hotter temperature, where it can reach approximately 40 Celsius degrees!
Super Class-A Amplifier – [Link]
DS1802 is a Stereo Digital Volume Control IC. It consists of two 65-position, 45kΩ digital potentiometers with logarithmic resistance properties incrementing 1dB per step. It can be operated under automatic software control via a serial 3-wire interface where wiper settings are written with 8-bit words, or under push button control with simple contact closure.
DS1802 Stereo Digital Volume Control – [Link]
This project is an easy audio amplifier based on 8 pin DIP LM386 integrated circuit.
The potentiometer is the volume control. The heatsink is screwed to an LM7812 12V voltage regulator. There are a couple of caps and a diode on there. The wire with what looks like gum on the end of it is actually the headphones jack wire with a three-pin header molded onto the end using that really cool putty “as seen on TV” that you knead together and it forms really hard parts. I used it to protect the super-thin wires of the headphones jack. The little chip on that board is the LM386. The red- and black-tipped wires coming into the top of the breadboard just left of the diode and the voltage regulator are the leads from a Radio Shack 12V, 500 mA wall wart.
LM386 Easy Amp – [Link]
Simon Inns builds this realtime PIC based audio spectrum analyzer. The analyzer uses Fast Fourier Transform routine written in C to run as efficient as possible on the 8 bit PIC18F4550 mcu. The output from the FFT is displayed using a 128×64 graphical LCD to allow a real-time view of an audio signal. [via]
PIC spectrum analyzer uses Fast Fourier Transform routine – [Link]
This project is an audio amplifier rated at 100W. An audio amplifier is an electronic amplifier, which it used to amplify low-power audio signals (20 hertz to 20,000 hertz) to a level that suitable for driving loudspeakers. This amplifier uses the TDA7294 IC from SGS-Thomson which it’s a 100 watt operational amplifier. Check construction details on the link below.
100W Audio Amplifier - [Link]
This project shows how to make blinking LEDs to music. It’s a simple project for anyone with some electronic skills. Plug this circuit into an audio source and the LEDs will blink to the rhythm of the music. The circuit is using the voltage from the audio input to activate a transistor and turn on the LEDs.
Blinking LEDs to Music - [Link]
This project is a Wav Audio Player based on PIC18F2550, it is able to play RIFF WAVE files and display some file information on the N6610 LCD. It plays the audio file via the PIC’s PWM with a simple RC filter on the output pin. The data is read by a SD card. Check it out.
PIC18F SD WAV Audio Player - [Link]
This project is a 2x2W Audio Amplifier based on LA418. This amplifier is very easy to build because it has not complicated parts and will cost around 4$. Check schematic and PCB on the link below.
LA4182 Audio Amplifier 2×2 Watts - [Link]
This circuit is a analog LED audio VU meter based on LM3915 that is the logarithmic version. Each LED operates with a 3dB difference from the previous one and a jumper is provided to allow dot or bar mode. This is ideal as power meter on amplifiers.
LED Audio VU Meter - [Link]