Here the simple mic pre-amp circuit design based on single IC LM358. The circuit is very simple, inexpensive and easy to built. This mic pre-amplifier circuit operated with 9V DC voltage, you may use 9V battery for this circuit. Component Parts List: R1, R3, R4 = 10K R2 = 1K R5 = 100K-1M Potensiometer C1… Read More »
Here the simple mixer circuit with 4 inputs and 2 operational amplifier (op-amp) modules: A basic mixer suitable for mixing microphones or even effects outputs. The overall gain from input to output is one if the pot related towards the input is full up. You can make this a net gain of ten (or any… Read More »
The circuit below is a Dynamic Mic Compressor circuit which is simple, easy to built, inexpensive but the results are quite satisfactory. Audio output sounded outstanding. The principle of this circuit is very simple, the first transistor is used as microphone pre-amplifier. Then a second transistor used as a buffer. And the third transistor is… Read More »
Below is a mic compressor circuit that uses transistors as active components. VR1 and VR 2 is used to control the tone from the microphone, while VR3 and VR4 strengthening works to control the audio signal in the compressor mic. C10 must be used in this circuit. The circuit I got from my local computer… Read More »
Below circuit is an echo chamber circuit which can be used for smoothing your voice from the microphone. This circuit may used for any kind of audio signal (microphone, radio, mp3 player, etc). The echo chamber circuit is great for human voice (karaoke), i doesn’t needed for music sound. This circuit is quite complex with… Read More »
This is the circuit diagram of a voice operated relay. It similar with sound activation switch circuit which will turn on and turn off (connect and disconnect) the switch depending on the sound input. The output switch of this circuit is act by a relay. Components list: R1, R7 : 1K R2, R4, R8 :… Read More »
This is a sound activated switch circuit. It’s will turn on and turn off based on a loud sound such as clapping your hands. You can adjust the sensitivity (how loud of a sound will activate the circuit) from a pin drop to a Mack Truck Horn. Very practical for a variety of projects. Add… Read More »
This circuit is a powerful three stage, 9V FM transmitter (Tx) with a range of up to 1 kilometer in the open. It uses an RF transistor in its output stage and two BC547″s for the first two stages. Distance of trans-mission is critically dependent on the operating Conditions (in a building or out on… Read More »
This is a simple audio pre-amplifier circuit using single transistor 2N3904. This easy circuit provides good gain to weak audio signals such as electret microphone. Use it in front of an RF oscillator to make an RF transmitter that’s very sensitive to sound. Power supply used for this circuit is wide range from 3VDC to… Read More »