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High-End Audio Modular Preamplifier
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 lot of facilities and various filters, but is drawn so the acoustic signal follows the...
Phono RIAA Preamplifier
The circuit use one simple, but good power supply, is enough its armor-clad by the remainder circuit, if it needs, with a aluminium, so that we avoid the noises. All the circuit can be placed in a small box, from which will only come out the RCA jack, the main power cable, in the back box part and the Diode Led D1, in front part. Good its are...
Portable Microphone Preamplifier
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 simple, due to the absence of mains cable and power supply. The circuit is based on a low...
Modular Preamplifier with IC Class A
An application, which is considered, of very good quality sound since the entrance transistors are working at Class A. The quality of sound depends to a large extent on IC1, which must be of good quality. It can be chosen from several IC with the best from the point of cost efficiency the proposed NE 5534 (NE 5532 for stereo construction) and...
Audio Preamplifier with Digital Volume
The circuit is a preamplifier with digital regulation intensity of sound. He is separated in three departments. In first schematic (Fig.1), is found the circuit of control of electronic potesometer. The control become from two pressing switches. The S1 (UP), that put up the intensity of sound and the S2 (DOWN), on the contrary, that lower the...
Phono RIAA Preamplifier
In this circuit exists a second designing proposal of preamplifier RIAA. The first stage uses discernible components and in second exist a opamp. [IC1]. In the negative feedback exist the correction RIAA filters. Certain points need certain discriminators: 1] capacitors C2 and C15, will be supposed to suit with the cartridge characteristics that...
Symmetrical Audio Class A preamplifier
The preamplifier that appears in the figure is a completely symmetrical preamplifier, from the input as the exit and it works in Class A. It does not have somebody innovation, simply it uses good solutions, in order the result is what should. Such proposal is the use transistors matched [Q1, 2], that finds in the same chip with result the...
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 highlight these characteristics.
RIAA Phono Preamp
This riaa Pre-Amp is the perfect solution to getting a signal off of your old turntable and into your mixing board. Whether you want to grab a couple of loops from a 70s LP record or just archive your record collection you need an riaa compensated pre-amp to do it. When grooves are cut in the vinyl of a record pre-emphasis is used to even out...
This circuit was submitted by Graham Maynard from Newtownabbey, Northern Ireland. It has an exceptionally fast high frequency response, as demonstrated by applying an 100kHz squarewave to the input. All graphs were produced using Tina Pro.
Audio Line Driver
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 use ordinary bell wire,loudspeaker or alarm cable for connection. The preamplifier must...
Dynamic Microphone Preamp
A low noise pre-amplifier suitable for amplifying dynamic microphones with 200 to 600 ohm output impedance. This is a 3 stage discrete amplifier with gain control. Alternative transistors such as BC109C, BC548, BC549, BC549C may be used with little change in performance. The first stage built around Q1 operates in common base configuration. This...
Tube Line Preamplifier Project
The interest for circuits of tubes, remains big. Thus I will give completed in enough big degree, circuit of preamplifier. It is mainly constituted by the department of main preamplifier, the department of input selector, delay of application voltage and connection output of preamplifier with the final amplifiers and the department power...
Stereo Preamplifier with adjustment tone
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 adjustment of all parameters become from a line monophonic linear potesometers,...
Moving Coil Head Pre-preamplifier
A special category of preamplifiers, they are the preamplifiers that undertake they amplification the low exit of Moving coil head, so that its drive to a input PHONO [RIAA] of preamplifier. With the moving coil heads, exist certain problems which it should we are careful in the designing of amplifier. The very low output level of head and the...
Three Tube PHONO (RIAA) Preamplifiers with ECC83
It is three circuits of RIAA, amplification of low signals of heads [MM], following different solution, each one, as long as it concerns the eq. In the circuit of PHONO 1, we have deephasis with pathetic filter placed between the two departments of tube V1. In PHONO 2, is followed the classic solution of energy deephasis. In PHONO 3, finally...
Stereo Preamplifier with Bass-boost
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, the bass frequency range is rather sacrificed. This circuit features also a bass-boost, in...
Audio Line High-End Preamplifier with ICs
Afterwards the Modular preamplifier presentation good is I present also a simpler circuit in the manufacture but very good quality. And in this circuit the philosophy that follow is: simple is also better. As you will see in the circuit, it was used only that a Volume potentiometer. Even the Tape Monitor choice, is considered more enough seldom...
Modular Class A Buffer preamplifier
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 remains at a very low level. Matching must be done with great care to the types of...
Low Noise Moving Coil Audio Preamplifier
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 amp we gain even lower noise. Also the reason we use PNP rather NPN transistors is...
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 moving-magnet cartridges, can be used in connection with both audio power amplifiers shown in...
ECM Mic Preamplifier
A microphone amplifier that may be used with either Electret Condenser Microphone (ECM) inserts or dynamic inserts, made with discrete components. Both transistors should be low noise types. In the original circuit, I used BC650C which is an ultra low noise device. These transistors are now hard to find but BC549C or BC109C are a good...
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. This simple but efficient circuit devised for cheap moving-magnet cartridges, can be used in connection with the audio power amplifiers shown in...
Balanced microphone preamp project
Well, it's pretty much a PAiA preamp - usual input circuity followed by one half of dual op-amp rigged in fixed 20dB amplification circuity, followed by second stage which is adjustable for up to 40dB amplification, for up to 60dB total. The power supply is a simple affair, supplying +-12V using 7912 and 7812 regulators. As ECM8000 is happy with...
Many designers opinionate that NFB loop controlled amplifiers are inferior because they degrade the sound, and yet I wonder what it is that these individuals think they actually listen to ? The fact is that most vinyl waveforms and CD pits, as pressed into their own disc collections, have already been mastered through a myriad of NFB loop...
Simple High Quality Preamp For Hi-Fi
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, however in this version, no RIAA (phono) input is provided - see the separate Project Page...
Low Voltage Preamplifier
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 stability. T2 realizes the amplifiers full voltage gain, and for low noise operation, T2...
Audio preamplifier circuits
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 other voltages you may wish to alter the 1K8 resistor to give symmetrical clipping at high...
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 microphones, and also show how to power a condenser microphone. The power source is typically a...
USB Microphone Line Level Preamp
The computer needs at least 180 millivolts peak-to-peak and the condenser microphone in my headset produces about 20 millivolts peak-to-peak into a 2.2k load with normal speech levels. There are USB ports on the machines, so I can use that for +5 volts. After a quick look in my parts boxes, I decided to put the input jack and output plug on the...
Single ic preamp
Another very simple audio preamp to build. all parts should be available at your very local electronics shop.
General use Preamplifier with 2N3904
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 meet this broad requirement, most amplifier designers include a single universal...
Audio Filters Circuits
Audio Amplifier Circuits
Audio Oscillator Circuits
Audio Mixer Circuits
Audio Equalizer Circuits
Audio Tone Balance Circuits
Beeper Buzzer Circuits
Vacuum-Tube Valves Circuits
Musical & Effects Circuits
Ultrasonic distance finder circuit
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is measured. There are three main categories of distance measurement methods in use: a) By...
Simple Metal detector circuit with CD4030
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to find something potentially valuable, hidden a few centimeters below the soil. So many...
Fully automatic watering circuit for flower pots
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This circuit comes as a solution to this problem. Depending on humidity of the pot at...
Simple deep searching metal detector circuit
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the circuit of this metal detector, it is possible to detect a metal coin in depth of 90 to...
Sub-Harmonic Bass Converter for Electric Guitars
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound, such as filtering or distortion. Instead, a frequency division system produces outputs...
Echo Depth Sounding Sonar for Boats
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the calibration of the rope. This arrangement still exists in some yachts. The big...
100W HiFi Audio Amplifier Circuit
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power supply must be symmetrical so that no electrolytic capacitors are needed at the outlet....
Plant-Pot Water Level Indicator Circuit
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower. The circuit of the device is shown in Figure 2. The water detection is made from the bottom...
Analogue Sound Preasure dB-Meter Circuit
The best human ear can capture sounds from 20Hz to 20KHz. These limits are known to be the broadest that can exist. Normally the normal limits range from 100Hz to about 13KHz and depend on the age and health of the individual. We for our measurements and to have a good accuracy we will get the limits of 20Hz to 20KHz. A sound to be heard does...
Digital Signal Integrity
Interconnection and Timing of Digital Circuits
CMOS Circuits Tutorial