Improved 3 Transistor Audio Amp
This circuit corrects the problem somewhat and allows a larger voltage swing and probably more output power, but I don't know how much without doing a lot of testing.
3 Transistor Audio Amp
Here is a little audio amplifier similar to what you might find in a small transistor radio. The input stage is biased so that the supply voltage is divided equally across the two complimentary output transistors which are slightly biased in conduction by the diodes between the bases.
This circuit turns-off an amplifier or any other device when a low level audio signal fed to its input is absent for 15 minutes at least.
Audio VU meter 9 leds
5 LED VU Meter kit is based on LB1409 IC from SANYO, which will indicates the volume level of the audio signal it senses
This is a great intercom circuit that can be used in many ways. It uses 22V to operate and maybe it will work at a lower voltage
60W Linear amplifier
The 60 Watt linear amplifier is simple all solid state circuit using power mosfet IRF840.
Cheap Audio Booster
Cheap Audio Booster
Useful for amplifying weak signals before amplifier.
Portable Audio Amplifiers
It is designed for portable cassette players and radios. You can also use it as your PC Audio Amplifier. A few external components required to build this circuit.
5-Band Graphic Equalizer
This complete high quality, low noise 5-BAND GRAPHIC EQUALIZER circuit is based around Monolithic Linear integrated circuit LA3600 manufactured by SANYO. This circuit is very easy to build and has good Quality.
200W Audio Amplifier
Infrared cordless Headphone Amplifier
Infrared cordless Headphone Amplifier circuit diagram.
Three Channel Audio Mixer
Three Channel Audio Mixer circuit diagram
20W Audio Amplifier using LM1875
20W Audio Amplifier kit is based on LM1875 IC.
20W Bridge Audio Amplifier
20W Bridge Audio Amplifier kit, based on the TDA2005 IC, a class B dual audio amplifier, specifically designed for car radio applications etc.
Stereo tape head preamplifier using LA3161
Stereo tape head preamplifier using LA3161 circuit diagram
Tiny audio amplifier using LM386
Small audio amplifier for weak signals. Simple to build.
Motorola Hi-Fi power amplifier
This is a very simple, low cost, Hi-Fi quality power amplifier. You can build it 5 ways, like it is shown in the table (from 20 W to 80 W RMS)
Speaker Box Audio Amp
Amplifier for your computer. Very serious electronic project.
Bass-treble tone control circuit
The LM1036 is a DC controlled tone (bass/treble), volume and balance circuit for stereo applications in car radio, TV and audio systems. An additional control input allows loudness compensation to be simply effected.
Amplifier of acoustic frequencies and preamplifier
Tendency of catering: 15V
Force of expense: 4,2Wrms in the 4W
Minimal signal of entry: 94mVp-p with preamplifier, 0,65Vp-p without the preamplifier.
3 Channel Spectrum Analyzer
This 3 channel 15 LED spectrum analyzer is the perfect addition to any audio amp project. It produces fantastic displays on three LED bars that can be individually adjusted for any particular frequency range.
Stereo Tube Amplifier
The circuit is simple, yet is capable of excellent performance. I designed it specifically for use as an amplifier for the digital sound card in my computer. Audio input can be from any two-channel line level device such as a television, CD player, or VCR.
Sound Level Meter
This nifty sound level meter is a perfect one chip replacement for the standard analog meters. It is completely solid state and will never wear out. The whole circuit is based on the LM3915 audio level IC and uses only a few external components.
FET Audio Mixer
This simple circuit mixes two or more channels into one channel (eg. stereo into mono). The circuit can mix as many or as few channels as you like and consumes very little power. The mixer is shown with two inputs, but you can add as many as you want by just duplicating the "sections" which are clearly visible on the schematic.
60W Guitar Amplifier
Bass, Treble, Harmonic modifier and Brightness controls.
Output power: 40W on 8 Ohm and 60W on 4 Ohm loads
The aim of this design is to reproduce a Combo amplifier of the type very common in the sixties and the seventies of the past century.
Three-Level Audio Power Indicator
This circuit is intended to indicate the power output level of any audio amplifier. It is simple, portable, and displays three power levels that can be set to any desired value.
Automatic Loudness Control
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 entire audible frequency band, as shown by Fletcher-Munson curves.
10W Audio Amplifier with Bass-boost
Audio amplifier that boosts bass tones.
Stereo Preamplifier with Bass-boost
This preamplifier was designed to cope with CD players, tuners, tape recorders etc., providing a 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.
The target of this project was the design of a small portable mixer supplied by a 9V PP3 battery, keeping high quality performance.
Portable Microphone Preamplifier
This circuit is mainly intended to provide common home stereo amplifiers with a microphone input.
This circuit, connected with 32 Ohms impedance mini-earphones, can detect very remote sounds. Useful for theatre, cinema and lecture goers: every word will be clearly heard.
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.
Precision Audio Millivoltmeter
Precision Audio Millivoltmeter. Uses audio for measuring voltage.
Portable Headphone Amplifier
Can be directly connected to CD players, tuners and tape recorders.
10W Mini Audio Amplifier
10W Mini Audio Amplifier with very small count of electronic components based around TDA2003 circuit. You can use this powerful amplifier in any small audio project. It is very small (6.5 x 4.5 cm). It outputs 10W and uses a 9V battery.
18W Audio Amplifier
18W Audio Amplifier made of transistors.
Two low voltage, low power zeners are used to control electronically the level of an audio signal. The attenuation range is from 6 to 58dB for an input current from 0.042 to 77 mA corresponding to a control voltage from 2.7 to 7.5V.
3 Line Mixer
This project is a 3 or more lines mixer. For more than 3 inputs you can repeat the input parts
Low impedance microphone amplifier
The circuit is a microphone amplifier for use with low impedance (~200 ohm) microphones.
50 Watt Amplifier
This is a handy, easy to build general purpose 50 watt amp. The amp has an input for a radio, TV, stereo or other line level device.
25W Mosfet audio amplifier
High Quality simple unit.
No need for a preamplifier.
Audio Perimeter Monitor
Used to detect sound in some area. This circuit has only two transistors and several passive components
Laser Communication System
Audio wireless transmitter and receiver. It uses laser beam from laser pointer to transmit audio signal. Not so applicable, but very interesting and easy circuit to build.
This is a four channel amplifier ideally suited for use with quadraphonic equipment such as a Sound Blaster Live card. There is no volume control,audio levels being directly controlled from the sound card itself.
Peak Reading Audio Level Meter
This circuit has minimal number of components and it's easy to build. It measures peak level of a sound signal. It uses
Audio Notch Meter
The controls may also be adjusted for use as a band stop (notch) filter or band pass filter.
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
6 Input Mixer
A simple mixer with 3 line inputs and 3 mic inputs using commonly available parts. The mic inputs are amplified about 100 times or by 40dB, the total gain with the mixer is 46dB.
Class-A-AB Amplifier 100w
A Class A // Class AB amplifier rated 100 Watts when driving a 4 ohm loudspeaker
Op-Amp Microphone Preamp
Audio preamplifier designed for dynamic or electret microphones. Uses several components which are easy to find. It has a 23.5k ohm input impedance. It can be used to amplify weak signals other than from microphone.
An amplifier to drive low to medium impedance headphones built using discrete components
Dynamic Microphone Preamp
A low noise pre-amplifier suitable for amplifying dynamic microphones with 200 to 600 ohm output impedance
ECM Mic Preamplifier
A microphone amplifier that may be used with either Electret Condenser Microphone (ECM) inserts or dynamic inserts, made with discrete components
15 Watt Amplifier
A 15 watt amplifier made using discrete components. Interesting and not so difficult do build.
22 Watt Audio Amplifier
22 Watt Audio Amplifier with only one chip TDA1554
Speaker Microphone Circuit
This circuit takes an ordinary loudspeaker and allows it to be used in reverse, as a microphone.
8 Watt Audio Amp
Here is the schematic for an 8 watt audio amp. This amp can be used as a simple booster, the heart of a more complicated amplifier or used as a guitar amp.
Digital Volume Control
Adjust volume digitaly on your analog devices
2N3055 Power Amplifier 60W
2N3055 Power Audio Amplifier circuit diagram
Mini-box 2W Amplifier
Mini-box 2W Amplifier Designed for self-powered 8, 4 & 2 Ohm loudspeakers. Contains Bass-boost switch.