The circuit described in this article is a MOSFET follower for driving headphones. FET followers can supply high current, but have a voltage gain of slightly less than unity. They are most suitable in applications where the input signal does not require....

e circuit, is a classic circuit of electronic crossover. Stand in for, the circuits of passive crossover that exist in all loudspeaker three way. The difference is in that, it should anymore we use for each loudspeaker a separate final amplifier. Thus for....

This is a small but quite powerful FM transmitter having three RF stages incorporating an audio preamplifier for better modulation. t has an output power of 4 Watts and works off 12-18 VDC which makes it easily portable. It is the ideal project for the....

This preamplifier was designed for low resistance sources like moving coil heads (MC). The circuit uses in parallel three duble transistors SSM2220 or MAT03 and by forming a diferential amplifier keeps noice low. Connecting this amplifier in front of a OP27....

This preamp is very simple, and will work under tough conditions. The input impedance is pretty high, so it won`t load down electric guitars. It will also amplify microphones. When I have a moment, I`ll make some additions that will optimize it for....

High Quality unit with LM833 or NE5532 Low noise Dual Op-amp. No need for a preamplifier. # Can be directly connected to CD players, tuners and tape recorders. # Tested with several headphone models of different impedance: 32, 100, 245, 300, 600 & 2000....

This circuit is designed to work at UHF frequencies in the range 450-800MHz. It has a gain of around 10dB and is suitable for boosting weak TV signals. The circuit is shown below...

This preamplifier was designed to cope with CD players, tuners, tape recorders etc., providing an ac voltage gain of 4, in order to drive less sensitive power amplifiers. As modern Hi-Fi home equipment is frequently fitted with small loudspeaker cabinets,....

Simple circuitry suitable for moving-magnet cartridges Passive high-frequency equalization. This simple but efficient circuit devised for cheap moving-magnet cartridges, can be used in connection with the audio power amplifiers shown in these webpages,....

This circuit will be useful if you have an electret microphone that produces a low audio (sound) level and you want to connect it to an amplifier or something like it. The circuit boosts the microphone output voltage to obtain an acceptable signal level.....

This preamplifier is requirement result of many friends to give a high quality preamplifier, capable to drive high quality power amplifiers with good sound, it`s not however difficult to making, it combines simplicity and handiness. It does not allocate a....

Proposed power supply for amplifier 100W v-mosfet [ 1 ] is what appears in the above form. It has separated supply for the various stages of supply, stage for power, stage for control, supply for preamplifier and for stage of protection. Whoever wants it can....

This is a special low voltage version of my audio preamp. T1`s emitter voltage is biased close to half supply voltage (1.5V) to allow for maximum output voltage swing. Both transistors are direct coupled and have closed loop feedback to aid temperature....

Tube amplifiers designed for headphones have the principal property that they can be used as preamplifiers too. In most cases, the output impedance of a tube headphone amplifier is (or should be) less than the output impedance of a tube preamp. This....

This circuit was submitted by Graham Maynard from Newtownabbey, Northern Ireland. It has an exceptionally good high frequency response, as demonstrated by applying an 100kHz squarewave to the input. I have produced some response graphs using Tina Pro to....

When the start switch is pushed, the output of the charger goes to 14.5 V. As the batttery approaches full charge, the charging current decreases and the output voltage is reduced form 14.5V to about 12.5V, terminating the charging process. Transistor Q1....

This circuit is mainly intended to provide common home stereo amplifiers with a microphone input. This circuit is mainly intended to provide common home stereo amplifiers with a microphone input. Using a stereo microphone the circuit must be doubled. In....

This preamplifier has a low output impedance, and is designed to drive long cables, allowing you to listen to a remote music source without having to buy expensive screened cables. The very low output impedance of around 16 ohms at 1KHz, makes it possible to....

Most audio amplifier systems must have preamplifiers with many different characteristics. These include high-gain linear response for magnetic microphones, low-gain linear response for tuners, and high-gain RIAA equalization for magnetic phone cartridges. To....

This design was born of frustration with the mic preamp in my Sony R91. It clips at ridiculously low levels, basically it has 28mV of headroom to deal with an input that could be as high as 1800mV (depending on mic & volume), so this design attempts to cure....

The circuit is so simple that there is little to say about it, but it gives very good results. Tr1 is operated in grounded base mode with input to its emitter to give low impedance input. The values shown give correct operation from 9v. If operating from....

The preamp circuit is completely conventional, and by necessity is AC coupled throughout. The artificial earth is derived by two resistors (R1 and R2), which will set the "earth" at exactly 1/2 the supply voltage. This is nominally 13.8V in all cars, since....

This preamplifier has a low output impedance, and is designed to drive long cables, allowing you to listen to a remote music source without having to buy expensive screened cables. The very low output impedance of around 16 ohms at 1KHz, makes it possible to....

This is a simple microphone preamplifier circuit which you can use between your microphone and stereo amplifier. This circuit amplifier microphone suitable for use with normal home stereo amplifier line/CD/aux/tape inputs. This microphone preamplifier can....

This is a design for a low noise microphone preamplifier, which is ideally suited to low impedance (600 Ohm nominal) microphones. One limitation is that it is not balanced, which is not a problem in a home recording environment, but will allow the mic lead....

A nice circuit for using with audio preamplifiers, or any other circuit that use potentiometer and you need to control it from distance. The circuit includes Infrared transmitter and reciever with motor controller chip BA6418N...

The amplifier in Figure 1 originally served as the photomultiplier preamplifier in a Doppler system intended for eventual operation in the Martian atmosphere. The design is based on a switchable array of six Maxim MAX4258 dual-channel video....

For those who are still with me, the preamp featured has optional tone and balance controls which may be omitted if desired (although I do not recommend this generally). The input switching may be extended if needed to accommodate more signal sources,....

Figure 1 shows the block diagram for the NTE789. The input signal form the detector is amplified by a lowdistortion preamplifier and simultaneously applied to both signal, generated by a local voltagecontrolled oscillator (VCO), is counted down by two....

The Stereo Tape Head Preamplifier kit is based on LA3161 IC from SANYO. Power supply - 9 ~ 12 VDC @ 20 mA. Output power - upto 200 mW. Input Resistance - 100 K? (Typ), Load Resistance - 10 K? (Typ). Low noise, good ripple rejection owing to the on-chip....

In recent years, following CD`s introduction, vinyl recordings are almost disappeared. Nevertheless, a phone preamplifier is still useful for listening old vinyl discs from a well preserved collection. This simple but efficient circuit devised for cheap....

This circuit is designed to amplify the input from a telescopic whip antenna. The preamplifier is designed to cover the medium waveband from about 550Khz to 1650Khz. The tuning voltage is supplieb via RV2, a 10k potentiometer connected to the 12 Volt power....