Audio and Amplifier Projects

The proposed 10 band graphic equalizer circuit can be used in conjunction with any existing audio amplifier system to get an enhanced 10 stage audio processing, and customized tone control. The circuit can be easily converted to a 5 band graphic equalizer by simply eliminating 5 stages from the shown design The Circuit Concept A […]

In this post I have explained a simple low pass filter circuit which can be used in conjunction with subwoofer amplifiers for acquiring extreme cuts or bass in the frequency range 30 and 200Hz, which is adjustable. How it Works Several low pass filter circuits for subwoofer application are presented all over the net however […]

In this article I have explained a single chip circuit which can be used for recording and playing back short voice clips or any audio clip ranging from 20 to 60 seconds. About the IC APR9600 The incorporated IC APR9600 is a programmable voice recorder chip which facilitates infinite number of recording/erase of audio files […]

The following circuit was taken from an old electronic book, it is indeed a very nice little two transistor radio receiver circuit which utilizes very few components yet is able to produce output over a loudspeaker and not just over headphones. Circuit Operation As can be seen in the given circuit diagram, the design is […]

The presented circuit of a musical greeting card circuit was requested by one of the keen readers of this blog, so I designed this interesting little circuit, which is simple and easily gets embedded inside any standard greeting card fold. Looking at the given circuit diagram, we see a design consisting of a very few number of components, rigged […]

The article presented below describes a very simple intercom system which can be built and installed at any required place very cheaply. The circuit utilizes just a single IC and a very few other components for the entire assembly. How it Works If you are looking for a simple and low cost intercom system for home installation, […]