This circuits allows you to use a cheap loudspeaker as a microphone. Sound waves reaching the speaker cone cause fluctuations in the voice coil. The voice coil moving in the speakers magnetic field will produce a small electrical signal. The circuit is....

This is the circuit diagram of a simple three transistor audio amplifier that can deliver around 100mW power to a 25 Ohm speaker. The diodes D1 and D2 provides a constant bias voltage for the transistors Q1 and Q2. The transistor Q1 works as a preamplifier.....

This 2 channels audio mixer is based on the 2n3904 transistors which forms 2 preamplifiers. The first preamplifier of the audio mixer has a high gain and can be used for microphone input, and the second one can be used to control the input of the audio....

This circuit is mainly intended to provide common home stereo amplifiers with a microphone input. The battery supply is a good compromise: in this manner the input circuit is free from mains low frequency hum pick-up and connection to the amplifier is more....

Even if a large number of album titles once available on vinyl are now, little by little, being proposed as CDs, not all are available and far from it. You may have treasures in your collection that you would like to burn on CDs. First, preserving a CD is....

Circuit IC1 provides a do amplification of 40 dB, which drops to about 20 dB when the frequency rises above 500 Hz. To minimize the (resistor) noise and the load of the op amp at higher frequencies, the value of R3 is a compromise. The associated polystyrene....

This circuit could be regarded as a simple alternative to the Sooper Snooper device featured elsewhere in this issue. It is based on the PreChamp preamplifier featured in the July 1994 issue of SILICON CHIP. It can be used to pinpoint or locate sounds coming....

4 Stage FM transmitter circuit diagram. It uses four radio frequency stages: a VHF oscillator built around transistor BF494 (T1), a preamplifier built around transistor BF200 (T2), a driver built around transistor 2N2219 (T3) and a power amplifier built....

Many times we needed to use a simple circuit of preamplifier, with few components and facility of made. This circuit use a opamp. the Motorola, TCA5550, that contains a double amplifier, as outputs for the adjust of volume, balance, treble and bass. These....

The heart of the circuit is an IC4822 named as IC1. IC4822 is a programmed ROM, which generates 16 musical tunes when it gets triggered. The main feature of this IC is that it has inbuilt tone generator, rhythm generator, modulator, oscillator, frequency....

This is a design circuit for modular arrangement that allows the amateur to choose only the modules more suited to his requirements in order to build a chain one to five modules long. For the minimalist, the Control Center module described in this pa ....

A dual channel audio preamplifier as an appropriate preamplifier for the high quality Audio Analog to Digital Converter AD24QS. It is, of course, easy to build a much smaller and much cheaper preamplifier with comparable functionality, but making it cheap....

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This LM12 audio amplifier circuit will provide a high output power on a 8 ohms or 4 ohms load impedance. The maximum output power delivered by this LM12 audio amplifier is around 60 watts on a 4 ohms load and 100 watts on a 4 ohms load on each channel. A....

This be Pre Mic circuit or Microphone preamplifier circuit model 2 CH. By this circuit uses integrated number circuit NE5532 or LF353. It perform enlarge sound signal from Dynamic Micro phone give the power goes up for subsequently submit to go to still....

There are two types of preamplifiers for magnetic phono cartridges. An example of the most common type is the one described in the March 2002 issue of SIL....

18W Audio Amplifier. High Quality very simple unit -- No need for a preamplifier Circuit diagram: Amplifier parts: P1 = 22K Log.Potentiometer...

The circuit given below is of a simple audio amplifier that can deliver 12W to an 8 Ohm speaker. Op amp IC TL081 is used as the preamplifier here. Actually any opamp with matching power supply ratings can be used instead of TL081. Transistors Q1 and Q2....

A unit which is often very useful, if we need to isolate, in sound circuits, two stage between them. Then we can use this circuit which has an amplified unit, which gain X1, we do not use total negative feedback, only local, with the result that distortion....

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High Quality, Discrete Components Design, Input and Tone Control Modules To complement the 60 Watt MosFet Audio Amplifier a High Quality Preamplifier desi....

Electronics Circuits Reference Archive Audio preamplifier circuits There are thousands of pre-amplifier circuits. These are three which have interested me and are a little different. Intercom preamp A very convenient way of making an interc....

This is a low cost fm antenna booster that can be used to listen to program from distant FM stations clearly. The antenna fm booster circuit comprises a common-emitter tuned RF preamplifier wired around VHF/UHF transistor 2SC2570 (C2570). This is the....

This tour, available in Stainless DIL 8 legs, can measure 4 analog voltage independent between 0 and 5 volts, and send the result of this measure in the form of four characters on a standard asynchronous serial link. Its serial output is di....

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Adapting one of my failed Tesla coils into a crystal radio set to show the neighborhood kids. I`ve run into the #1 problem everyone faces not enough antenna to generate a strong signal. I read somewhere that a proper  AM antenna should be between 100 500 ft....

The following is an example for a very simple and high quality JFET preamp. You can use this to amplify a very low signal sources. FET transistors are usually not used independently in preamplifiers. In most of the cases they are paired with bipolar....

The design of the circuit is aimed to create a preamplifier for television systems that would operate in the UHF frequency range of 450 MHz to 800 MHz and....

In order to obtain a good audio reproduction at different listening levels, a different tone-controls setting should be necessary to suit the well known behaviour of the human ear. In fact, the human ear sensitivity varies in a non-linear manner through the....

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DCF77 Preamplifier Circuit DiagramA popular project among microcontroller aficionados is to build a radio-controlled clock. Tiny receiver boards are available, with a pre-adjusted ferrite antenna, that receive and demodulate the DCF77 time signal broadcast....

This is a Simple Phono Preamplifier Circuit Diagram. In recent years, following CD`s introduction, vinyl recordings are almost disappeared. Nevertheless, a phono preamplifier is still useful for listening old vinyl discs from a well preserved collection.....