Open – Close No Tub. The offset circuit including output fast.
I was stepping into ICs using C instead of applying all the columns in my hi-end audio equipment.  Voltage +-15V.
Small PCB 12.6X6.3 cm. Print zoom – Zoom in itself.

Mic mixer circuit

Welcome back to Free circuit dot com again,today we have still audio circuit for your build .
The circuit is a basic 3 input mic mixer circuit with the popular opamp 741 ICs.
Two 741s are used here.U1, U2 are used as preamplifiers.
They produce a gain of around 40 dB to the individual input signals.
The U1 is wired as a summing amplifier to add the signals from three preamplifiers.
IC2 also gives a gain of around 5decibel to the final output signal.
Total gain of the system is around 45 dB.

Electronic Part List

 R1, R2, R3  1K 1/4W Resistor 
R4, R5, R6 10K Logarithmic Pot 
R7  1Meg 1/4W Resistor 
R8, R10  10K 1/4W Resistor 
R9, R11  100K Linear Pot 
C1, C2, C5, C6 0.1uF Ceramic Disc Capacitor 
C3, C4   22nF Ceramic Disc Capacitor 
U1, U2    741 Op Amp 
J1, J2, J3    Input Jacks Of Your Choice 

Note
R9 and R11 control bass and treble, respectively and R1-R3 are level controls.

because the circuit draws such low current, we using  2 X 9V batteries  that can be used for a power supply.

You should be build the mixer in a metal case will cut down on noise.

50W Amplifier Circuit TR 3055 , 2955

Welcome to Free circuit dot com,today we come back with audio power amplifier circuit.

Little pieces of sound equipment, but offline. Voltage only + – 35 more than this would not be sure.
5200 to 1943 using 2955 instead of 3055 with offline without any problems.

Sound reasonable … it is the underlying circuit is really Basic. No help at all. To create one would have to select the device a bit. Because there is no such a key enabling Boost Traping, Constance Current Source, Constance Voltage, Tempurature stable control, ect to which the help of these are important in helping maintain stability of operation of the circuit. Listening to other players in the house.

We have PCB and parts layout and real assembly for you see.

50Watt PCB

50 W Parts Layout

Preamp PCB with TL072

Welcome back to Free Circuit dot com ,Today,We take the preamplifier circuit with TL072,You can connect with Guitar,DVD player or Iphone.

The preamplifier circuit is shown in the figure has some interesting characteristics that separate “normal” on the assumption that there is such a thing. The circuit was built by an amplifier TL072. This design is simple and offers an excellent range of tones. The structure is designed to obtain a large amount of profit, which is ideal for guitarists who want to fully distorted “fat” to get his job. It is the figure of the circuit.

The preamp uses a dual op amp that any amplification. The single transistor is an emitter follower, and maintains low output impedance after the master volume control. As shown in the figure, with a classical guitar input, it is possible to obtain very large overdrive sound by winding up the volume, then the captain of an appropriate level.

Preamp Assembly layout

The frequency response is deliberately limited to the lower end plate to avoid extreme highs and cut to help reduce noise and the response to the normal requirements for the guitar to a minimum. If you TL072 OP AMP, as shown, you will find that the noise is a problem, especially at high gain with lots of treble boost. I recommend that you use an OPA2134 audio file at a premium, you will find what is perhaps the quietest guitar amp you’ve ever heard. In any gain setting, there is more noise guitar pickup is the prototype circuit noise and carbon resistors preamplifier.

Voltage low warning circuit

Come again for voltage low warning circuit ,You can apply in your car to check voltage.
The same circuit can be used as an indicator of low voltage alarm when 10 volts Zener diode replaced by a Zener 1N5233B 6.2 volt.

The connection pin 4 of the LM339 and two resistors instead of 10K level sensor.
Connect a 1K resistor in the output of 12 volts (pin 3 of LM339) and a 10K resistor to ground (pin 12 of LM339). Set potentiometer reference voltage 0.5 * Low operating voltage of the street, the output voltage of 5 volts pot , If you travel a circuit with 10 volts. You can reduce the calculation of delay exceeds the threshold of 6.2 volts instead of 10 volts and current, if the index you want to shorten.
Electronic Part
R1, R3 1K 1/4W Resistor
R2 5K Pot
U1 LM339 Op Amp IC
D1 1N5233B Zener Diode
D2 LED
BZ1 Piezo Buzzer

Low voltage warning beeper circuit

Welcome back to Free circuit dot com for today we have the electronic circuit,This circuit is an alarm circuit for low battery status. It gives an audible and visual low voltage 12V battery powered devices. If the battery voltage exceeds the limit set (typically 11V), the circuit is idle. If the battery voltage must be below the setpoint, the LED and the speaker will beep periodically to warn of the impending loss of power punches. The circuit was designed for monitoring solar energy systems, but it can also be useful for automotive and other 12V.

How does it work?
U2 has a market regulated 5V voltage reference. U1 is wired as a comparator compares the voltage fixed 5V regulated voltage at the wiper of VR1, which is proportional to the 12V. If delivery is below the setpoint, the output of U1 goes low, turning on Q1 and food for the beep and the LED.

The acoustic signal consists of U4, a tone generator, and U3, a pulse generator with low duty cycle. The tone can be varied by adjusting R7, the beep rate be changed by adjusting R5. A small amount of hysteresis is provided by R1 and the current through LED1 and the beeper, which separates the points on and off the circuit.

U2 has a market regulated 5V voltage reference. U1 is wired as a comparator compares the voltage fixed 5V regulated voltage at the wiper of VR1, which is proportional to the 12V. If delivery is below the setpoint, the output of U1 goes low, turning on Q1 and food for the beep and the LED.

The acoustic signal consists of U4, a tone generator, and U3, a pulse generator with low duty cycle. The tone can be varied by adjusting R7, the beep rate be changed by adjusting R5. A small amount of hysteresis is provided by R1 and the current through LED1 and the beeper, which separates the points on and off the circuit.

Beeper use low voltage battery
Connect the circuit to the 12V source you wish to attend. Turn on S1, if the battery voltage exceeds the set value, nothing should happen.

If the battery voltage drops below the set value, the LED light and a buzzer will periodically speaker. If the beep is annoying, turn off S1. Make sure the battery fast charge, over discharge, the life of most rechargeable batteries shorten.

remote control tester circuit with sound

This circuit is designed, modulated amplitude (AM) IR light beam demodulation drive a speaker.

This circuit is designed, modulated amplitude (AM) IR light beam demodulation drive a speaker.

Stereo phono preamp circuit

We found this circuit on my pc ,i think ,it is Crazy  to post on website this circuit is Stereo Phono Preamplifier (RIAA Filter) circuit Separate phono preamp are nothing new in the audio, but they were mostly to the professional sectors of the industry until the late 80’s limited time in which the compact disc was the dominant force in the audio playback and manufacturers face the law of diminishing returns often opt for the phono EQ section of the amplifier or a cheap IC to cast the function to use in less than ideal sound.

This opens up a whole new market for good quality separate amplifier so seriously still have their vinyl simply not an option, but a buy. But it should also be noted that the purchase of high-quality phono is preamp also an excellent way to can replace your Upgrade Set-up the amplifier without which there is a good way to find a balance in your audio chain to be extremely hot tubes amplifiers allow precise-sounding preamp, and vice versa with one of these wet-sounding English jazz to-amp to play their LP in through the purchase of a valve stage or a sparkling Japanese, etc.

Note that a low power MC cartridges with the help you need either a premap specifically supported, and made sure to get enough and deep enough impedance as a pick, is a low power, or alternatively get one of those fancy MC preamp also. Also be aware that many of the cheaper valve based phono Processors have limited bass response, this is due to the limited available open loop gain and techniques used to correct this often induce phase errors.

Premic IC circuit with LM741

Welcome back to free circuit dot com,We still have post amplifier circuit ,today,We have a pre amplifier circuit for one microphone inputs with IC LM 741.
The 741 is used here. IC1 is used as a preamp. Produce a profit of about 40 decibels to individual input signals. IC1 is wired as an amplifier census to add the signals of three preamps.
 IC1 also a gain of about 5 decibels to final output. Total earnings of the system is about 45 decibels.

Note:
 • Use 15 / 15V DC dual power supply for this circuit.
 • All inputs and outputs to be connected to the ground.
 • The capacitors C1, C2 and C3 must be rated 10V to 30V and other capacitors.
 

General Description

LM 741 IC diagram

 The LM741 series are general purpose operational amplifiers that exceed industry standards like the LM709 function. They are direct, plug-in replacement for the MC1439 709C, LM201, and 748 in most applications. The amplifiers offer many features that make it almost foolproof protection against overloading the input and output, no latch-up when the common-mode range is exceeded, and freedom from oscillations. The LM741C is identical except that the LM741C LM741/LM741A have their guarantee of performance on a 0 ° C to +70 ° C temperature instead of -55 ° C to +125 ° C

Power amp 400W IRFP448 Circuit

Amplifier circuit today,We would like to show you for the MOSFET 400 watt amplifier is amplifier on my kW shares the same circuit and basic PCB layout.
  The only real difference is the number of output devices to the device.
  We have using The IRFP448 design while the MOSFET amplifier 14 O / P devices.
  These amplifiers can be used for virtually any application that requires high performance, low use Noise, distortion and excellent sound quality. Examples would be subwoofer amplifier should FOH stage
  Amplifiers, surround a canal a very powerful sound amplifier, etc.
  The 400W MOSFET-amplifier has four key stages of amplification. We are looking to start any   Phase appropriate detail.

The bias and buffer stage
  As the name suggests All Q ,C and ZD the Bias and buffer phases. Its main goal is to provide a stable MOSFET Gates  and offset voltage and the voltage buffer amplifier stage of the High Resource capacity. What would have without the phase response and the effect
  Slew rate is indeed very bad. The flip side of the coin is not the extra step
  Introduction of an additional dominant pole in the amplifier feedback loop.

400W MOSFET PCB

Power amp 400W IRFP448 PCB

and We have the electronic components layout thus as below

Power amp 400W IRFP448 PCB Layout

We have to continue in power circuit PCB and components layout

Power for Amplifier 400W IRFP448 Mesfet PCB

400W Power IRFP448 Mesfet PCB Layout

  
  The final stage of the Current Gain Stage
  Also to what the name suggests this stage converts the voltage developed in the VAS
  and provides all the amps required to drive at 8 or 4 ohms. 2-ohm loads are possible
  for several minutes at a time. In fact, I have tested more than 1600 1kW amplifier
  Watts RMS at 2 ohms. But that would not be recommended as a long-term exposure at all.
  If it is higher than the figures of the STI-amp.
  Power to the AV amplifier 800
  The components of the power for this amplifier are as follows, and are favored
  A channel or a power module alone.
  1 toroidal transformer with a rating of 1kVA. Primary windings are made to fit

6 band graphic equaliser circuit using 741 op amp

Welcome back to Free circuit dot com,today we have the audio circuit for improve your sound system,this circuit is 6 Band Graphic Equaliser ,you can adjust sound in low ,mid and high which circuit used IC 741 Op-Amp.

Audible Frequency spectrum is treated in six bands: 50Hz, 160Hz, 500Hz, 1.6kHz, 5kHz, 16kHz. All potentiometers are linear type of 100k. The circuit offers a lot of cut / boost for normal use.

We have show you the parts list thus as below .

ELECTRONIC PARTS LIST
R1, R2, R3, R4, R5, R6 27kΩ
R7 470kΩ
R8 330kΩ
R9 100kΩ
R10 4.7kΩ
R11 4.7kΩ
VR1, VR2, VR3, VR4, VR5, VR6 100kΩ
C1 100n (104)
C2 33n (333)
C3 10n (103)
C4 3.3n (332)
C5 1n (102)
C6 300pF (301)
C7 100µF 16V
C8 4.7µF 16V
C9 47µF 16V
IC1 741 Op amp 

Power for the circuit of the amp / preamp itself derived. The wide range of power supply (6V-15V) makes the circuit very versatile. The power consumption is negligible.

Subwoofer filter at 11-90Hz circuit

Welcome back to free circuit dot com ,today we have the sub filter circuit for improve your sound with low bass .

Subwoofer filter circuit to remove for separate pre amplifier to drive the low frequency sound a lot. In tone, call tone, normal Can not be done … is a fine deep low bass sounds like a bass drum, or at a movie complex in a low voice if we can be heard with But to add cabinets and amps.
The subwoofer circuit is pass low frequency with in 11-90 Hz.
Switching power supply 12V cut out if they need to use +-15V.
I had change the Capacitor to cut out vocals per the red circle mark.
We have provide the PCB for you thus as below too.

Subwoofer filter at 11-90Hz PCB

and Real assembly Picture thus as below

12AX7_Pre-Tone Circuit

The Amplifier circuit today ,This is one circuit. That people do come and tell a good sound…tube 12AX7 popular.
But the author said. Bass very good. But also pointed to short .. they all.
To Change capacitor in tone, some better then offline … (do not ask whether to change how much value it can be purchased anywhere.)
Because people associate I see they already know offline circuit. That should do what where. This circuit has regurate also without hum sound.

Who do I try to print. Then try plugging tubes. If only I was fit. Purchase of equipment to complete before then to measure leg holes will fit ..
Circuit is very much different, but I do not want to. It copies the same fear of missing the offline.

PCB show thus as below

Preamp 12AX7 PCB

Telephone audio interface circuit

We can interface home telephone to audio devce or PC  are available from an explosion using an abstract agent and the capacitor band of rogue devices. A non-polarized capacitor, alternating with the agent capable of band connection from DC accepts ambagious plenty firmly in the agent for the tire expect the on-hook state to anticipate. The capacitor has a voltage of up to the evaluation of the Aiguille launched Arena voltage of 90 volts, the extra voltage of 48 volts or 138 volts to accept a whole.

was abstinent locally and can change with the location, a 400-volt or value added is recommended.

Audio relative of the agent is about 100 mV, with an antenna-impedance amplifier or tape recorder can be connected. This may explain 3-transistor amplifier also be used. For overvoltage protection, two diodes are connected, the Agent Audio Accessories absolute millivolts to 700 arrests during the Aiguille Campanology signal. The diodes can be most any silicon Emblem (1N400X / 1N4148 / 1N914 or other).

The 620-ohm resistor serves to reduce the burden of the band’s performance is associated with a low effective resistance.

Police siren circuit

Come back to Free circuit today ,I would like to present the sound circuit that like police siren sound for your apply to another project ,

The Police siren circuit given here is based on a circuit NE 555 timer IC.
The circuit uses 2 each for NE 555 ICs (IC1 and IC2) and the core working parts of the circuit.
There are 2 timer ICs are wired to work as astable multivibrators. But these 2 timer ICs operate at different frequencies.
Regrading IC1 is slow unstable multivibrator operating at a frequency of 20 Hz and a duty ratio of 50%, while IC2 works as fast as 600Hz astable multivibrator.
The output of IC1 is fed to the control pin (pin5) of IC2. With this regard, the output of IC2 frequency modulated with the frequency output of IC1.

 The circuit can be powered by a DC voltage ranging from 6V to 15V. Power is used, the 12V DC. The volume of production can be increased by inserting an amplifier circuit on the output stage of this circuit.

light alarm circuit

Reagarding this circuit sent out an alarm when its LDR sensor is exposed to light by sun or lamp.
A 555 astable multivibrator was used here which sent signal a tone of about 1kHz upon detecting light.
The sensor when exposed by light completes the circuit and makes the 555 oscillate at about 1kHz with transistor to drive current.
The sensor is also shown in the circuit diagram. It has to placed making an angle of about 30 – 45 degrees to the ground.

Sensitivity can be adjust with P1.
 This makes the sun light to flow through it to the ground and prevents the alarm from going on due to the stored light on the sensor.

Wire Loop Alarm Circuit

Integrated circuit anti-theft alarm system, wire or other lack of a simple circuit.
When the lack of wires or cords lacking. MOSFET, it is working or has input voltage at pin G and thus it has a high current flows through the pin D-S that Micro piezo siren was so loud.

Electronic Part List

R1  100K 1/2W 1% Resistor 
R2, R4  10K 1/2W 1% Resistor 
R3 1  Meg 1/2W 1% Resistor 
C1, C3  0.1uF Ceramic Disc Capacitor 
C2  0.01uF Ceramic Disc Capacitor 
IC1  4001UBE Quad 2-i/p NOR Gate 
Q1  MPSA14 Low Power NPN Transistor 
SIREN  Micro piezo siren 12V DC 150mA, 110dB @ 1M 
LOOP  See “Notes” 
 The loop can be any type of hookup wire, with a maximum resistance of about 90K. Using very thin wire (40AWG, for example) will make a very sensitive trip wire, but will shorten the distance it can be strung due to the high resistance.

 The siren can be replaced with a relay to drive external loads.

Audio light modulator circuit

The Audio light modulator Circuit for add organized the joy of music at functions at home or outdoors.
This article here is a simple circuit where the light is a small fraction of the audio output at the speaker terminals of the modulated audio amplifier.
The output of the speaker terminals of audio amplifier (used transformers in transistor radios) with a transformer connected through a non-polarized capacitor.
  The use of the transformer is important to isolate the source of the audio circuitry in the sensitivity of VR1 potentiometer input to the T1 set to ensure that the guide is not until the AF will pay above certain.

Surround Sound Decoder circuit

This is a simple surround sound decoding. Output to the right and left stereo tape or CD player can be connected to the input signal range and 4 output signal of the circuit can be connected to a surround sound amplifier power amp or two stereo power amplifier.

The main function is op-amp LM741  to amplify signals received by each of the input signal with a signal through the filter signal with capacitor 10uF both before opamp and pass through Opamp again.

For power supply is +/- 15 volts

Audio Peak indicator circuit

A simple circuit PEAK indicator of foliage of the musical signal. Whenever the signal exceeds the + 4dB, turns on the LED D1.

 It is useful in the console of each channel of sound amplifiers or other final application, we needed.

With the price of the tour, which begins with high level +4 dB (1.25 V RMS). Adjustment for different signal levels, we use a lawnmower capacitor C1. T? circuit can work perfectly with the track, Mic / Line Balance. after C11.

Electronic Part

R1= 10Kohm
R2= 1.2Kohm
R3= 220Kohm
R4-5= 4.7Kohm
 C1= 47uF 25V
C2= 2.2uF 25V
D1= LED RED
Q1-2= BC550C

surround sound circuit

This system uses the front and rear with three or more channels to create directional sound sources and the surrounding envelope of sound. It can be digital or analog as the term is widely used for the introduction of home theater systems in recent years. The surround sound system includes a variety of ways in which a sound source is enhanced by the quality of audio playback with the addition of speakers by discrete audio channels.

Part List
All capacitor = 10 uF
All Resistor = 1k ohm
Op amps 741 ,1458(dual op amp) may be used

The purpose of the construction of this circuit is to provide a decoding scheme using the surround sound system and is not intended to replace the surround sound decoder available on the market because they contain different features and functions. The circuit, however, can be used with other basic features as a standard decoder. Early versions of Dolby Digital have been eliminated and replaced with Dolby 5.1, DTS and other versions of success that support the transport layer and managing digital audio signals. The basic process requires four channels Dolby Surround information center, rear, front left and right surround contained in a signal of two channels. The decoding of the four channels is made possible by a decoder chip that sends a signal to the appropriate destination.

Dolby Digital is a trademark of technologies developed by Dolby Laboratories for a number of loss audio compression where the compression and decompression of data results in a production that is characteristic of the original, but still useful in some way. Dolby Digital can be done in mono, 2 channel, 4 channel, 5.1 channels or 6.1 channels. However, it must be remembered that the term Dolby Digital does not refer to the number of channels it contains, but on the digitally encoded audio signal. Although Dolby 5.1 and 6.1 is often referred to simply as Dolby Digital, in most typical applications.

To enable its spread in many directions, Dolby Digital 5.1 is the addition of stereo rear surround that make them more accurate and more flexible. They can also provide greater importance to the effects of low frequency with the addition of a dedicated subwoofer channel. Encoding and decoding of Dolby Digital requires the same amount of frequency range and power, as the main channels as opposed to Dolby Pro Logic where there is a limited frequency response and only minimal power to the rear channel.

Other versions of Dolby Digital Dolby Digital EX are as follows, using the matrix technology with the addition of a single rear surround channel stereo tracks and a center channel and functions as its predecessor, Pro Logic, Dolby Digital Surround EX, which provides support for 5.1 soundtracks that is compatible and cheap way for a center rear surround channel for best results localized, and Dolby Digital Live (DDL) which is used for interactive media such as video games such as real-time hardware encoding to convert any audio signal from a game console in 5.1-channel Dolby Digital and the transfer by a Sony / Philips Digital Interconnect Format (S / PDIF) Dolby Digital Plus offers increased throughput, the improved coding techniques to reduce compression artifacts, compatibility with existing, and support for more audio channels and Dolby TrueHD is a lossless audio codec that supports advanced support the necessary codecs for HD DVD.

The operation of the circuits from over transportation in stereo surround information on the audio signal from the main volume of the circuit. This allows for the left channel Lch attached to the model TL072 IC1A IC1b and which is attached right channel UC. The outputs of these operational amplifiers used as input buffer for the subsequent stages of the circuit. IC2C is responsible for the synthesis of signals from left and right channels that feed the output of center speaker while IC2D is responsible for the increase of the phase difference between left and right channels which is encoded into two channels and will be introduced into the rear speakers. We must ensure that the negative terminal of rear speaker is not simply because the ground in parallel with the main speakers.

The output of delay unit power IC2D regulated its rear speakers. This would create the sense of spacing depending on the size of the room. This will integrate its op-amp signal delay IC5 MN3004 has 512 levels. Since IC4 MN3101 is a clock signal, provides time IC5 as it functions as an oscillator in the circuit. Variable capacitor C17 sets the time delay in the circuit. The presence of filters in the circuit is to keep the noise to be generated during the process. These filters can be set to reduce rates by more than 8 kHz and below 100 Hz, to be able to drive the rear speaker. The rear diffuser is low because its input is encoded with a bandwidth of 100 Hz to 8 kHz. The filters are built around the IC6A / B which is also an output buffer. A potentiometer is placed in each output to aid in the control and regulation of speakers and amplifiers. The power supplied to the circuit is 15 V and each output can drive a single power amplifier.

condenser mic preamp circuit

Here is the schematic circuit diagram for electret condenser microphone amplifier. using a LM1458 dual op amp Operational Amplifier IC. electret condenser microphone by bias circuit and preamp

The circuit takes the audio signal rom the condenser microphone and amplifier it, so you can use the microphone as the input to some device which wouldn’t normally accept microphone level signals (which are very low).

This amplifier has an adjustable gain, which is performed via. R1 (a 1 Mega Ohm variable resistor). It controls the feedback of the LM1458 dual opamp, which in turn drive a LM1458 output IC.

Electronic Parts List:
Q1,Q2 – LM1458 transistor
R1,R2,R3 – 4.7k ohm resistor
R4, R5 – 10k ohm resistor
R6,R7 – 47k ohm resistor
C1, – 0.22uF ceramic capacitor
C2, – 1uF ceramic capacitor

MIC1 – electret condenser microphone
All resistors are 5 or 10 percent tolerance, 1/4-watt. All capacitors are 10 percent tolerance, rated 35 volts or higher.

birdie doorbell ringer circuit diagram

Variable Resistor “P1″ is an experimental value. Start with 220 Ohms or more, and modify it to suit your
needs. The transistor is a type of general purpose and is not critical, almost all
PNP work.

L1 is a bell-transformer which is usually already present in
Home. If you wish, you can use a battery instead of the transformer housing.
Simply connect a 9 volt battery (or wall adapter) to ‘A’ ‘B’ points (A =) of
diode (D1) is to protect the circuit from accidental polarity reversal and
optional, but necessary as a rectifier for use with the transformer housing.

Tranfermer T1 is a PNP general purpose transistors, and probably nothing will work. L2
come from an old transistor radio. They look like small transformers and are
usually red or green. You have to play with different processors
the sound can vary depending on the value.

It is a 8 Ohms type and must be greater than 200milli-Watt.

I used a 2Watt type, but nothing more will 0.2W. Sounds like a real bird and
When you release the button on the side of the story is slowly disappearing.

I used this circuit in my house for over 20 years and also to the “Birdie” for
others. Although the old circuit, the experimentation and the final result yet
punch.

the circuit simple to apply and modify to more band such as 6 band,8 band.

Could you see detail in circuit thus as picture right side.

Electronic parts list

EQ 3 band circuit

IC1= TL072, NE5532
C1-11= 10uF 25V
C2= 33pF ceramic
C3= 2.2uF 63V MKT
C8= 1.2nF 63V MKT
C4= 47nF 63V MKT
C5-7= 4.7nF 63V MKT
C6= 22nF 63V MKT
C9-10= 100nF 63V MKT
C12=47uF 25V
R1-2= 47Kohms
R3-4-5-12-13= 10Kohms
R6-7= 3.3Kohms
R8-9= 1.8Kohms
R10= 270ohms
R11= 22Kohms
RV1-2= 100Kohms Lin.
RV3= 470Kohms Lin.

Mini Auido Mixer with FET

The easy circuit mixes 2 or more input channels into one channel (eg. stereo to mono).
The circuit must as many or as few input channels as you like and consumes very little energy mix.
The mixer is shown with two inputs, but you can only add as much as you want simply by repeating the “sections” that are clearly visible on the plan.

Electrical Part List
R1, R3 10K Pot
R2, R4 100K 4.1 W resistor
R5 6.8K 4.1 W resistor
C1, C2, C3 0.1 uF capacitor
Q1 2N3819 Junction FET
MISC Wire, Shielded (Metal) Case, Phono or other connectors for power
Note
1- Many or as few channels needed to be added to the mixer. Do this simply by repeating the command “sections” are clearly indicated on the chart. A version of this mixer I saw had 25 entries!
2- A shielded case is probably necessary to prevent disturbances and vibrations.
3- The circuit can be powered by a 9-volt battery.

Mixser_LM353

The Mixer with IC LM353 With this circuit can mix four separate audio inputs. Each input is high or low impedance microphones accepted, record players, tape or aux signals. You can set the gain for each input by adjusting each pot. With Stereo / Mono switch you can just inputs 1.2 and 3.4 or in the mono position combining a combination of all four inputs. Signal is 20 Hz to 20 kHz. with a very high input impedance and very low distortion to the output of the complete protection against short circuits. This circuit is an amplifier with an input impedance of 2000 Ohm drive.

Wring Mixer Circuit Picture

The above  circuit picture is my project mixer that were used to mixed two input sound or audio.

The input audio that we use are mp3 and microphone respectively.

10 band EQ circuit

This circuit uses a single chip, IC TL074 for achieving a 5-band graphic equalizer for use in Hi-fi audio systems. The 5-band graphic equalizer is true for radio-cassette player, and car stereos. This unit features: low distortion and low noise, wide range of operating power voltage (3.5V to 16V), low-power (5 mA), Wide Dynamic Range (DE = 2.1Vrms/VCC = 8V) and built an amplifier input and output buffer.

The TL074  is a five-point graphic equalizer, which has integrated all the functions necessary for a CI. The IC is the system of five sounds and control input and an output buffer amplifier. The PDF below contains detailed information on the wiring diagram for the 5-band graphic equalizer with a single IC / chip (BA3812L). The circuit shown in the table works around the five frequency bands: 100Hz, 300Hz, 1kHz, 3kHz, 10kHz.

Electronic Parts  

R1….20= 10Kohms
R21….40= 1Mohms
R41= 10Kohms
R42= 1Kohms
R43…..52= 2.2Kohms
R53…..62= 47Kohms
R63-64-66-67= 47Kohms
R65= 10Kohms
R68-69= 47 ohms 1/2W
IC1…3= TL074
RV1….10= 100Kohms  lin FADER
S1= 2X4 SW for stereo
RV11= 10Kohms  log.

C1= 180nF polyester
C2= 18nF polyester
C3= 100nF polyester
C4= 10nF polyester
C5= 47nF polyester
C6= 4.7nF polyester
C7= 22nF polyester
C8= 2.2nF polyester
C9= 12nF polyester
C10= 1.2nF polyester
C11= 5.6nF polyester
C12= 560pF polysterine
C13= 2.7nF polyester 
C14= 270pF polysterine  
C15= 1.5nF polyester 
C16= 150pF polysterine 
C17= 680pF polysterine 
C18= 68pF polysterine
C19= 360pF polysterine
C20= 36pF polysterine
C21= 4.7uF polyester
C22-23= 33pF polysterine
C24= 10uF 25V
C25-26= 47uF 25V
C27…32= 47nF polyester

4ch band mixer circuit

The circuit consists of 4-channel mixer with mono channels 1-4, while for the stereo channels 5-6. 

The number of input channels can be varied, while the choice between mono and stereo channels. The RV1-6 regulates the volume and channel players. The balance between the two channels is achieved by RV7-12. The adder adds the two b IC1a signals of input channels. The mower two TR1-2 on each channel provides the upward adjustments of each IC, as regards the size of the output signal as you want.

The settlement of three bands in the stage of the equalizer, where the output of the console has been IC1a-b. There was a gain of one and is responsible for the separation of former levels driven from the device. The use of headphones is possible by the existence of a circuit in the region IC2A-b, their production can be produced in the connectors JF13. The use of stereo VU meter to visually display the volume. The connection JF12b resumed the supply of different circuits, which consists of a mixture of excitement.

Modules for the mono input channels IC1, or other types of integrated circuits for reversing and regulating the gain of the unit from low to high microphones. The input module for micro-electronic scale line has a constant control of the scene 22K ohm pot. The preamplifier of the microphone to use transistors to regulate the zener diode voltage of the main line. The module input channel stereo is connected to a profit has increased the value of resistors in parallel with the capacitors. Other circuits of the main circuits connected stereo phono preamp, 3 equalizer, power and monitor mixer inputs for selection are the headphone jack.

EQ-5-band circuit

This circuit uses a single chip, IC MAIN BEARINGS MS226P  to achieve a 5-band graphic equalizer for use in Hi-Fi audio systems. The 5-band graphic equalizer is true for radio-cassette players, stereos and car radios. The device features: low distortion and low noise, high power voltage range (3.5V to 16V), low dissipation current (5 mA), Wide Dynamic Range (HOV 2.1Vrms/VCC = = 8V), and built in input and output buffer amplifier.

The MAIN BEARINGS MS226P is a five-point graphic equalizer that has all the necessary functions integrated on a single integrated circuit. The IC is equipped with five channels of sound control and input and output buffer amplifier. The pdf file below contains detailed information on circuit diagrams for the 5-band equalizer with a single IC / chip (MAIN BEARINGS MS226P). The circuit is given in the scheme around the five frequency bands: 100Hz, 300Hz, 1kHz, 3kHz, 10kHz

6Mixer channels Circuit

Many friends ask me, an audio circuit MIXER for different applications. I’m going to circuits that can make you start as you wish. These can be requested in modules of entries for each circuit, depending on what you intend the mixer, the same place as the number of input channels that you file. Below I have a lot of circuits with different levels of quality and complexity. All circuits, and proposes that they are easy to maintain a very good quality. For those interested, they have little patience. Soon I will give the project the professional level of the combination of audio signals console.
   

   
In Fig. 1, the main draw of the mixer is 6ch. It consists of 6 input channels. Channels CH 1-4 channels are in mono. The route you choose for this place where you can input connection, balance or be IMBALANCE [symmetrical or asymmetrical] have PHANTOM POWER electret microphone, with different input connectors. Channels CH 5-6, are intended to be used in stereo. The number of input channels can increase as long as you want, the choice between mono and stereo channels. Further details on the input circuits I separately for each circle. The output of each channel to drive the RV1-6, regulation potesometer sound level.

With RV7-12, we create the conditions for equilibrium between two channels [potesometer Panorama [MIX]]. All signals of input channels at this stage are added to two adders [IC1A-b], where each channel has two trimmer TR1-2, the profit of each IC to settle, adjust the level of production signal in the plane we want. They can be removed if you need anything. The next step is an equalizer [Fig. 9], Book III of the Regulation. The แ IC3-B to form the output of the mixer, they have a profit and they are essential isolation of the previous steps, with the unity we seek. Who they want, there is a headphone drive classic helmet to give IC2A-b production in jf13. It may also be present, but also optical indication of audio level meter with a stereo. Circuit, you can choose between what I give in the category of VU meters, or others that you want. The range of individual circuits is the power, connect the JF12b in touch and gives a series of constraints, the likely need. .

Part List

6 ch mixer circuit

IC = ua741
Below the mixer circuit 3 line inputs and 3 mic. The mic inputs are suitable for low impedance 200-1000R dynamic microphones. ECM or condenser mic can also be used but should have applied a bias resistor. As with any mixer circuit, a slight loss is always in place. The final summary must overcome a gain of 2 or 6 dB at them. Level of the input line should be approximately 200 mV RMS. The microphone inputs have increased over 100 times, or 40dB, the total gain of 46dB with the mixer. The microphone input for microphones, producing more than 2 mV RMS at 1 meter designed. Most microphones meet this standard.

Mixer 4 Input Circuit

Circuit Diagram Right shows for 4-channel sound mixer circuit using three Norton-opamps.

 The input levels able to set by potentiometers P1 or P3. Furthermore, which each input level able to trimmed with support of trimmers pots P4 to P6 to adapt each input to the source. The resistors at the non-inverting inputs of the opamps work as DC bias and set DC output at 50% of the power supply for this powered audio mixer.

  All 4 inputs signals are summed by the 4 opamp A4 through the resistors R3, R7 and R11. The commom volume level is cotrolled through the potentiometer P7.

You able switch an input channel on or off through the switches S1 and S3. An input channel is turn off that its switch is closing. It is also possible to replace these mechanical switches with transistor gates. with doing so, you can build an analog multiplexer circuit that can be easily expanded by several inputs.

distortion circuit

Overdrive is the only extreme clipping distortion.
You can use your clip PWM output when the input level is too high.
You back-to-back diodes in the feedback loop REG.
You can conduct two cooking FPGA-to-back diodes, which are connected to the mainland.

The parts for this Distortion Effect (Fuzz) are:
J1 – J2: 1/4 INCH MONO FEMALE CHASIS MOUNTING JACKS
C1 – C5: 0.1 MICROFARAD CERAMIC DISC CAPACITORS AT 50V
P1: 100M POTENTIOMETERS
P2: 10K POTENTIOMETERS
R1 – R2: 1K RESISTORS
D1 – D2: GENERAL PURPOSE DIODES
IC1: 741 OP AMP

Circuit, which is Audioguru describes the simplest type of distortion type overdrive and could be described as fluff.
Much will depend on the exact type of overdrive you want. If this is the kind of overdrive that you get the amplifier to the maximum, then distorted and leads quite dificult.
This can be done efficiently using the amplifier and speaker is overloaded and ecoustically balanced miced and again.
All sorts of things in the game, phase shift, attenuation, Come Get disruption speakers, etc.

Sound channel distortion in non-linear amplifier (changing course). This type of signal distortion is particularly desirable for many guitarists. Originally, this type formed in a clay tube amplifiers. The only problem is that the amplifier valve is only suitable for the production of sound at a very high volume. It is ideal for live entertainment, but otherwise.

On Dummy Load (non-durable good, it should be) to simulate the reactive load speaker amplifier player in different game situations and styles, using the “amplifier to the desired level, and dummy load to regulate the volume.

However, replacing the silicon age, the new design of tube amps solids, and now those options are for the rich musicians! On the other hand, some solid state linear amplifier design is similar distortion sounds and other types of distortion sounds. The great advantage is that non-linear amplification can be made in advance to the amplifier and distortion, and lower production volume is also available.

Here is a simplified circuit distortion pedal that I built. It is designed to work in a consistent performance. The first step is biased, the voltage followers (buffer) upon entry into the Vcc / 2 for each offer. The second step is a soft high-gain AC amplifier cutting. Unity DC gain amplifier output is changed VDC / 2 low-pass filter on the output filter high frequency components (too much fuzz otherwise). Input and output is connected to AC.

With this device, 9V battery for power, gain control in the second step, illustrated volume control on the output and footswitch to avoid disruption of (not).

I use this camera with a guitar processor is preparing to add some delay / reverb. There is a useful noise Nice for solo and string energy leader.

6 Channel Graphic Equalizer Circuit with TL074

The EQ circuit is very easy to build and has a good quality. You can do it with component stereos portable tape recorders, radio cassette recorders, radios, etc. ..
Operational amplifiers on one chip. 6-band equalizer for a channel can easily by externally connecting capacitors and resistors, which are formed for (resonance frequency) UPDATE. Series connection of two makes TL074 (6 to 10 bands) and multi-band. It is very stable in the capacitive load. Maximum voltage 20V max VCC must not be exceeded. The operating voltage is about 5 to 15V. Use of force with pin-room shorted, the causes are the destruction or damage to the IC. Use when mounting the IC on the board of directors or, make sure that the pin does not contain spaces Lot, shorted, etc.

Electronic Part

IC1-2=TL074
C1=1uF 100V
C2=15nF 100V
C3=150nF 100V
C4=33nF 100V
C5=8.2nF 100V
C6=1nF 100V
C7=470pF 100V
C8=680nF 100V
C9=680nF 100V
C10=150nF 100V
C11=39nF 100V
C12=8.2nF 100V
C13=2.2nF 100V
C14=470nF 100V
R1=47Kohms
R2-5-18=150Kohms
R3-4=10Kohms
R6….17=10Kohms
R19=100Kohms
RV1…..6=100Kohms Lin  .

Regarding the project is ten band graphic equalizer for one channel (mono) audio system. If you would like to Stereo EQ ,You need build 2 similiar circuits for 2 channel (stereo) audio system.

The audio equalizer build based on IC  TL074 with low noise JFET op-amp that will give you high quality audio output.

Electronic Part List

10 Channel Graphic Equalizer Circuit by TL074

All Resitors is 1/4W 1%
C1=47uF/25V
C10=27nF 100V
C11=12nF 100V
C12=6.8nF 100V
C13=3.3nF 100V
C14=68nF 100V
C15=33nF 100V
C16=18nF 100V
C17=8.2nF 100V
C18=3.9nF 100V
C19=2.2nF 100V  
C2=47pF
C21=560pF
C22=270pF
C23=150pF
C25=150pF
C26=10uF/25V
C3=150pF
C4=1.5uF 100V
C5=820nF 100V
C6=390nF 100V
C8=100nF 100V
C9=47nF 100V
IC1…3=TL074
J1…3=RCA Jack
R18….27=220Kohms
R2-5-31=1Mohms
R3=47Kohms
R4=15Kohms
R6-28=10Kohms
R7….17=1Kohms
RV1=250Kohms Lin.
RV2…..12=4.7Kohms Lin.
S1=2X2 SW

The Circuit is designed to produce an amplifier using a TDA7294 audio integrated circuit allocation schemes for 60 watts of power.
Terminology

* Amps – something like a built-in amplifier and is designed for the delivery and provision of adequate and high maximum output directly drives speakers or fees within a certain percentage of distortion
* TDA7294 – monolithic integrated circuit in 15-watt multi-packs separately for use as audio class AB amplifier in Hi-Fi field applications such as high-profile television, home stereo powered speakers designed for short and their short-circuit protection very low noise and distortion, thermal off, mute and standby functions, not on / off noise, high performance, not Boucherot cells DMOS output stage and high operating voltage range of
* Amplifiers Class AB – operates as a class-B amplifier that almost all of the crossover distortion by removing a small amount of bias current that constantly flows through the output transistors

Circuit Explanation

100W audio amplifier circuit

Using the integrated circuit TDA7294 is best suited to operate in Hi-Fi audio applications, amplifier class AB. Sovereignty is capable of delivering both 4 ohm and 8 ohm loads, since the IC output current and a wide range of voltage. In addition, 8 ohm load with 0.1% harmonic distortion (THD) can be supplied with 50 W RMS, with the addition of sufficient power and the minimum number of components. Eliminates the presence of heat sink water temperature at a rate of 1,4 ° C / W. In standby mode, is treated with PIN-9, while the MUTE input from the pin 10 is treated. In standby mode is always a priority for the MUTE input.

The amplifier will be activated immediately, while inclusion. This is certainly connected through lessons without constantly on the supply rail. The conversion of clicks is by increasing the time constants of C5 C6 and & R4 & R3 can be eliminated. Due to internal thermal protection of the IC, the temperature at 145 ° C can cause MUTE condition and at 150 ° C, the amplifier is in standby mode. The Circuit amplifier must not be made without the presence of a radiator that internally to generate a negative supply rail is connected to be operated. In IC, the radiator of the amplifier in a grounded metal enclosure to be mounted in isolation. The maximum voltage for 8 ohm load 40V to 30V for 4 ohm loads, a transformer with 80 VA and 150 VA for two modules in a stereo amplifier rated.

25W ClassA Audio Amplifier circuit

This circuit is a simple class A audio amplifiers. But with zero distortion, Q1 is a switch is in operation or shut down, so that no load current through the resistor R2. In the best case, the tension in Q1 and the load resistance equal to the Class A operation.

A 100K potentiometer (R3) and a 1-meg resistor (R1), and a simple tea-Variable Bias Circuit. Plase voltmeter between drain (D) of the 1 Quarter and the dissemination of soil and adjust R3 for a meter to half the supply voltage.
Applications IRF511 project much as it is pupola build the electronic circuit.
Nearly everyone will be resistance value for R2 used, as maximum power and the FET are not exceeded.
A resistor value of 22 to 100 Ohms is a good choice for experimentation. For high flows, adapted to be used on a radiator.

Description
   The amp is “El Cheapo 2-30, and was valued at a maximum of 30 watts per channel into 16 ohms. It uses a single power supply regulated power and a capacitor connected speakers. Having had the original, I can now reproduce the scanline detailed information. It was a very simple amplifier, used for almost complementary symmetry power amplifier. For those who are younger than me who had no idea what I am talking about quasi-complementary symmetry system used in time when the PNP power transistors were expensive and silicon devices have been pretty useless. If you want a kind of voltage and current rating, it was necessary to use NPN devices. The quasi-complementary output stage uses a (discrete) from Darlington to the positive side and a complementary pair to the negative (or a rider to a PNP-NPN power transistor coupled).

Meanwhile, in these days when you high gain and the current capacity adequate, germanium transistors would still ruled supreme. Provided they have been used in applications where the leak was not a big problem, germanium devices very well – it’s not entirely the amplifier output stages are, however. Even then, the majority of speakers were 16 ohms, with only a few dare to 8 ohms. All that was less than the almost unknown in 1964.

Figure 1 shows the circuit – it was an amp cheap compared to most offerings of the day. In addition, it was possible to sound respectable – built again in comparison – and me and my many friends from the date of this amplifier with a passion – guitar amps, Hi-Fi, you name it, El-Cheapo went !

Note that the types of transistors are referred to the original equipment. Most are now outdated, but it will be shown a list of skills below.

Those were the days when the transistor is the 2N3055 power of choice (NPN course), and there was no PNP devices remotely equivalent to less than 5 times the price, and even these were much lower. Consequently, almost complementary output very common, and even this is still the case with most IC power amps. The quasi-complementary output stage is the most popular until recently a fairly PNP power devices still available. Immediately, almost everyone started with Darlington NPN and PNP devices connected to the output stage (such as T3 and T4) – The funny thing is that it demonstrated back in the mid-1970 that the full connection Darlington sounds made (or at least measures ) worse than the quasi-complementary phases. Is not progress a wonderful thing?

The input stage of the El-Cheapo is not subject to phase problems of the long-tailed pair, because the class a driver (or SAV – Voltage Amplification stage) is used as the entry. Ampere led in this way often inherently stable. There is a big problem with DC offset of course – the item refers to the negative supply. If the earth (ground), it is no problem, but it precludes the use of this design with a dual supply. The DC is not a problem with capacitor connected speakers.

As shown, the gain for the audio frequency is 18 (25dB), a sensitivity of 1V for an input power of 40W means. The closed loop gain is set by R4 and R7. Since the score is taken after the output coupling cap, the latter does not affect the low frequency response – but this provision creates a network of underdamped filter that causes a 4.5dB peak at about 5 Hz. Increasing C7 4700UF eliminates this problem all respects.

In the original article, there were several variations of the design, but I do this amp based 40W form here. The variations were mainly based on lower voltages, but also a parallel (dual) output stage for the odd low impedance.

Note that the amplifier is great, and the input impedance of the amplifier itself is 1k (R4). For this reason there is an emitter follower (Q1) before the amplifier impedance to the right to convert into something useful. The described system has been far from ideal – a better solution would be to leave everything to the left of C2 and the drive circuit of a DAC (C2 should be reversed if the ADC supplies used alternately remove).

Regulated Power Supply

Power Supply Circuit For 25W hifi

The circuit is prepared as specified, and simple power amplifier with a low open-loop gain is a good idea to maintain a buzzing low. Using a regulated power Desirable Not usually but in this case is probably justified. Germanium transistors were used as shown in Figure 2 (all medium and high power transistors and germanium / PNP).

Because the amp PSRR (Power Supply Rejection Ratio will), only 36 dB, it will provide a noise problem with a non-regulated supply. It is noted Note that step emitter follower (Q1) contributed the bulk of the supply noise – LEAD good for the floor of the DAC amplifier.
The controller is easy, BUT would have worked well enough as indicated. 62V 1W zener Normally the unit, a power for the 60V amplifier gain (similar to the use of ± 30V with power over conventional split). Compared to today’s standards, hoods Probably the filter are too small (like Bouchon The loudspeaker coupling), but I’ll present it as it was originally described.

The TDA1010 is a monolithic integrated class-D audio amplifier circuit in a single pass 9-in-line (SIL) plastic.

 6 W audio power amplifier in car applications 10 W audio power amplifier in mains-fed applications.

The device is designed primarily as an amplifier to 6 W car radio to be used with 4 wall 2 impedances Wload. The wide voltage range power and flexibility of the IC is an attractive proposition for the turntables and tape recorders with output power up to 10 W.

6W audio amplifier cirucit

The wide voltage range makes this circuit ideal for applications in the area and the battery-FED devices such as televisions and turntables. The volume control stage has a DC logarithmic control characteristic with a reach of over 80 dB, control is by a variable DC voltage from 2 to 6.5 V.

Pre-Amp Tube Circuit

Preamp Part List
R1-7=1Mohm
R12-13=100ohm
C9=4.7uF 250V*
R2=100Kohm 1W
C1=220nF 250V*
U1=ECC82
R3-8=1Kohm 1W
C2=220pF ceramic or mylar U2=ECC81
R4=1.2Kohm 1W
C3=2.2uF 350V*
RV1=2X100Kohm log.
R5-11=5.6Kohm 2W
C4=1000uF 16V
RV2=2X100Kohm lin.
R6=100Kohm
C5-6=2X50uF 450V
RL1….6=Relay 12V 2X2 [1A] 
R9=22Kohm
C7=1uF 250V* 
R10=100Kohm
C8=220nF 630V *polypropylene or MKT

Power supply Circuit

Power suply
IC1-2=LM317*
R1=2.2Kohm 5W
R2-4=100Kohm 2W
R3=680ohm  5W
R5-6=220ohm
R7=470ohm  1W
C8-13=10uF 16V
C1=33nF 630V
C2…..5=2X50uF >350V
C6=4700uF 25V
C7-9=100nF 100V
IC3=7812  [1A]
C10-15-19-20=47uF 25V
T1=230Vac / 200V 0.15A
C16=470uF 25V
T2=230Vac / 12V 3A
C17-18=100nF 100V
F1=0.2A slow
BR1=4 X 1N5408
BR2=4 X 1N5408
BR3=4 X 1N4007
F2=0.1A fast
TR1-2=4.7Kohm trimmer
S1= Switch 2X2 10Aac
RL7=12Vdc Relay 2X2 10A
D1…..7=1N4007 EMI RF Filter 230Vac/6A
D8=12V 0.5W zener * with heatsink

Input Selector - Delay Drive Circuit

Input Selector – Delay Drive
R1…..5=1.2Kohm
R6-8=1Mohm
R7-9=10Kohm
R10-11=1.2Kohm
C1=100nF 100V
C2=10uF 25V
C3=22uF 25V
Q1-2=BD679
IC1=4081
D1……5=3mm Red
D6……9=1N4148
D10-11=3mm Green LED
LED S2=SEL 1X6 step
S3=1X2 mini switch

60w audio amplifier circuit vol2

If you want to build, you need to find a good project. As I said earlier, I built and I am very happy. The amplifier is of such a system driver booster high ideal bi-amp circuit with a simple single-supply. It is as if all amplifiers must be stable, but it means nothing to me, like many of my old drawings were unstable. This amplifier is by far the easiest and most stable I built.

To install it, set the maximum force 470K potentiometer. Measurement of the current amplifier and slowly adjust the resistance of the VR1,VR5 to read 1.65 to 1.7 was reached.

30w bipolar amplifier circuit

Although currently a small 30watt amplifier IC for an easy to use. And small, but for a sound developper predisposed than a transistor.
Today I bring all offers integrated audio power amp with 30watt output.

The 30W Amp Bipolar by TP9634 and TP2788 Transistor is easy to build and very inexpensive.
To power 24V> 2A.

Transistor :TP9634 and TP2788 be mounted on heatsink.
Can be directly connected with CD player, tuner and tape recorder.

100W MOSFET CIRCUIT

Circuit description: 
The 100-watt amplifier, basic research has been developed, which builds and (relatively) easily one a reasonable price. Has performed better (read: musical quality) than the standard STK module amplifiers are produced by using practicable and in any stereo receiver mass market today. When I built this thing, it was because I needed a 100 WPC amp and I wanted to spend the money. So I designed around all the parts I had in store.
The level design is more or less, and I’m sure there are no commercial units are similar. Knowlwdge For me, it is not an exact copy of the economic entity, nor I am aware that patents on Topology. For manufacturers to experience improved a lot and I know that improvements can be made but the idea was easy to hold and be able to do Anyone can do circuit of the United Nations and has the patience to do a sloppy job.
The input stage is a win is lf351 op amp, most of the open sky, as it stabilizes the dc voltage at rest. This then feeds a phase crossing, the swing voltage (-), Rail reference.

 The slope of the stage is an improvement Darlington High Linearity frerqency with. 2SC2344 the same collector has a large capacity Rather basic tension on. The MPSA42 demonstrate with a Low-Z and has a C (OB) PF few that is submerged by an effective CAP 33pF pole-splitting. And the stage) 2SA1011 the active load (current source, which provided an approximately 20 mA. The current scene is limited by a 2N3094 approximately 70 mA in worst case.
The result is a complete with outputs in Darlington complementary parallel. You could even though they cover, with one, if only 8 ohms easy to get to load the disk use is not recommended this. The use of machines in parallel increases the ability to drive reactive load (such as a significant current during the voltage waveform crosses zero and provides a high voltage and high curent through the transistor at a time) from L ‘ amp draw Can a High damping factor reduces and the maximum power transistor PROVIDE Peaks (remember, the profit on a drop of power transistors as the current increases).
       Compensation and poly case and a zero. The op-amp pole and the pole generated by the CAP 33pF, and the resistance of 470 ohms MPSA42 bias control. (the part of 33pF can benefit multiplied.) PF The capacitor 22 provides for compensation of lead and feedback will ADOTTAT from production tranconductance Rather than the production itself. It was in this way, the phase introduced by the output transistors, the feedback is not high frequency for the visa. This closed loop intorduces politicians, high-frequency limits. The two capacitors compensation must be type-1-creamic (NPO) mica or silver – with zero coefficients voltage signal.
          Amplifier Project was to be a 2-channel + / – 55 volt unregulated Run furniture, making up to + / – 48 volts at full load. It uses a 40-0-40 volt, 5 amp toroidal transformer, a rectifier bridge, 10,000 UF and filter covers per page. When using a standard EI transformer, a 6-amp rated units used. With this power, which produces 100 watts continuous, both channels driven into 8 ohms of resistance, without clipping. DB headroom and dynamic medium, and the United Nations. For more space, download voltages up to + / – 62 volt circuits may be used without modification.
Among other things, is the pattern in Postscript.
RESTRICTIONS:
           Without changes, the amplifier 4 ohm speaker systems are currently driving is no limit. The limit of a short circuit around a 4.5 A peak current, conventional speaker loads are discussed. (E ‘course at a higher peak current of the output swing approaches the rail.) If you perform either of these high-end speakers with the minimum means of impedance uncle, or that the stay is for REAGENT The range of most audio frequency (0.5 + J3.2 ohms) you might have a better amplifier than this. If the highest yield Motorola power transistors are used, the operation of a 2 ohm resistive load without any problems (), except for heat.
‘ve Never seen a slew-induced distortion on this amp with a CD of the band-limited (22 kHz) signal. I suppose fans of real high-end pieces can beat mixed with a TTL square wave signal with a pilot tone of a pick-19KHz stereo and Crank It Up will ensure that there is spectrum Spinges around, but who listens ?
Possible changes: (What power if I mo ‘?)
            The output transistors are Toshiba (Young 2SD424/2SB554) can not shoud USE superior supply voltages with a volt + / -60. If you intend to promote more use in parallel, or use the pairs 250 watt Motorola (MJ15024/MJ15025). A very low impedance should be increased, the slope of phase distortion in a drive with more than a basis for the release of Darlington Generating or add another gain stage current. Higher-beta (s faster) power transistors with reactive load is not worth a crap. Non-FT High When you replace sections is certified to have a fair distribution of the second chance.
              NE5532 op-amp can be used in input phase. If more than used the way for the + / -15 volt shunt regulator (symmetric ins UCCISE Bessel filter, etc.), the fall of 2.7K resistors Reduce might, for example, to maintain regulation 1.8K ohms. 2.7K resistors, but also can add up to 4 lf351 the type of op-amp regulator (Ho-hum balanced inputs 347 for a quad setup, in fine, DJ UN to prevent).
Recommendations of construction:
            The equalizer output and thermal transistor (2SC1567) to be mounted on a common heat sink – a unit measuring 5 centimeters high, with a rib 8 inches wide by 1.25 fins should do well for a channel. (You can see if pleasant) side of the case from them. Most applications do not require refrigeration normal than that. 2SC1567 And the reason for the Project for the bias regulator output was chosen because it is completely isolated – the version is more ECG mounting options. TO-3 outputs for the hardware is always convenient and easy to use.
The driver transistor amplifiers and voltage (2SC3344/2SA1011 couples) all require that, as a heat sink. Individual TO-220 heat sink is sufficient for the council – to dispel the tension of about 1.4 watt amplifiers. A common piece of 1 / 8 inch thick 1 cm x 4in. Aluminum angle will be long enough for all 4 on every channel, but be aware that they must be designed to take advantage of natural ventilation, must be and the transistor insualted.
Reasons attributable to keep separate from others, and a point. If this fails, the distortion high (5% or so), or are even vibration.
The bias output stage must be set to below about 25 milli ampere transistor output. This requires a value some time to stabilize, by You need more than an hour or so check during initial setup. Measure, measure the voltage across the emitter resistor and using Ohm’s law. This way you can participate in current output transistors in parallel at the same time to change and see if it was a serious discrepancy. Parties With the data of the same code, should not be turned off by more than 10%, after heated. Distortion power amplifier can amount used, but it takes more care to fix it. If you raise a quiescent current of more than 50 milli amperes per page, the value of the emitter resistors.
Initial Checkout:
Something just do not connect! Apparently a mistake, insignificant, can put your house on fire! (In addition to the blow out is worth 30 dollars in a microsecond transistors.) A variac will work in theory, but can the amplifier BOLT on the rail, if the offer is inadequate. I suggest using an Ballast Resistance – a 60-100-watt bulb in series with the AC power cord. Otti is a bright flash when you tap the application, it must be (almost) as the supply load current to reach its nominal value down. Amplifier and then typically work at low volume. If the amp draws too much power for any reason, the bulb shines, increase the resistance, and to limit the power to the circuit. In general, it is either a mis-wire (using DMM) Oscillation O (pointing to an area or RF power) of the metro. When the lamp is dim-dim-Bright-Light … And then the amplifier and marginally stable layout grounding should be reviewed. The values of the capacitors of adequate compensation should be, if they are not significant changes in the state. Mine is stable, as it is.
Further information:
The circuit is in PostScript, it should be printed Situation In soloist. Emitters of the transistors are designated by an “E”. I was too lazy by arrows on the symbols of transistors – and I use it in this way more than a year.
Find a particular problem? MCM (1-800-543-4330) has all the transistors. The total cost for a stereo version is to be between $ 150 S $ 250, a second type of operations of the case it could to find the transformer, and the heat sink. If you pay for ‘list’ of all to have, probably cost about $ 1,000 to build.
The information will HERIN is no guarantee, no warranty expressed or implied. Do not stand aside for the accuracy of the data is the author of technical information or the use of such false or assumed.
The equipment described in this article was designed, built and tested on my personal time with my personal resources.

headphone amp circuit

This circuit is primarily to provide common home stereo amplifiers with a microphone. The battery power is a good compromise is free in this manner the input circuit by the low hum pick area and connection to the amplifier is easier because of the lack of power cord and of diet.
Must be doubled with a stereo microphone the circuit. In this case, two separate level controls are better than one dual potentiometer stereo combined.
Low current drawing (about 2mA) ensures a battery.Circuit operation:
The circuit is based on a low noise, high gain two PNP and NPN transistor amplifier with negative feedback, stabilized by R6, working conditions very carefully.

The level is attenuated by P1, but at the same time, the stage victory lowered because of the increased value of R5. This unusual connection of P1, helps to achieve a high degree of input, so) to meet a wide range of input sources (0.2 to 200mV RMS for 1V RMS output.Notes:
THD is about 0.1% @ 1V RMS (all frequencies).
Maximum voltage input (cursor control level at a maximum) = 25 mV RMS
Maximum input voltage (level control cursor position in the center) = 200 mV RMS
Place the circuit in a metal case is highly recommended.
Simply the result of this device to the AUX input of the amplifier with shielded cables and connectors appropriate.

The following shows the basic measurement results …

60W audio power amplifier circuit

Reduced the value of the Class A-based resistance to 560 ohms **
Increased the value of the bootstrap capacitor 100uF
Decreased Stabilization 100pF caps on (she was formerly 220pF)
Added the output inductance and damping resistance (see News)
** It is conceivable that with a few transistors, the value of 560 ohms is not correct. If this is detected, you should “optimize” this resistance to at least maintain DC offset. If you really wanted, you could even with a 2k trimpot (), and set it for at least DC offset. It is best to wait until the first temperature stable, but it will not change much anyway.

Apart from these changes, the amplifier is loaded with highly original and provide a + /-35V (voltage), as indicated at 70W into 8 ohms give completely satisfied. In his life, many of the above mods have done, because I never had the schedule when I needed him to find, as often as it went, like me! It is an evidence of the fair amplifier that can handle all types of resistor and capacitor replacements are made, and it still works well.

The noise and distortion figures are a bit pessimistic – there is so little distortion at 1V (20V or for that matter) that my major problems for the disruption, has a readable measurement. The oscilloscope output shows that most of what I see is noise – the integration of the production (my scope is that it is not) to eliminate the noise shows very little at all.

tube preamplifier circuit

Preamp:Electronic Part List

R1-7=1Mohm
R2=100Kohm 1W
R4=1.2Kohm 1W
R3-8=1Kohm 1W
R5-11=5.6Kohm 2W
R6=100Kohm
R9=22Kohm
R10=100Kohm
R12-13=100ohm
RV1=2X100Kohm log.
RV2=2X100Kohm lin.
C9=4.7uF 250V*
C1=220nF 250V* U1=ECC82
C2=220pF ceramic or mylar
U2=ECC81
C3=2.2uF 350V*
C4=1000uF 16V
C5-6=2X50uF 450V
RL1….6=Relay 12V 2X2 [1A]
C7=1uF 250V*
C8=220nF 630V *polypropylene or MKT

Power supply cicruit for tube amp

Power suply :Electronic Part List

R1=2.2Kohm 5W
R2-4=100Kohm 2W
R3=680ohm  5W
R5-6=220ohm
R7=470ohm  1W
BR1=4 X 1N5408
BR2=4 X 1N5408
BR3=4 X 1N4007
RL7=12Vdc Relay 2X2 10A
TR1-2=4.7Kohm trimmer
IC1-2=LM317*
IC3=7812  [1A]
C1=33nF 630V
C2…..5=2X50uF >350V
C6=4700uF 25V D8=12V 0.5W zener * with heatsink
C7-9=100nF 100V
C8-13=10uF 16V
C10-15-19-20=47uF 25V
C16=470uF 25V
C17-18=100nF 100V
D1…..7=1N4007 EMI RF Filter 230Vac/6A
T1=230Vac / 200V 0.15A
T2=230Vac / 12V 3A
F1=0.2A slow
F2=0.1A fast
S1= Switch 2X2 10Aac

Input Selector - Delay Drive Circuit

Input Selector – Delay Drive : Electronic Part List

R1…..5=1.2Kohm
R6-8=1Mohm
R7-9=10Kohm
R10-11=1.2Kohm
C1=100nF 100V
C2=10uF 25V
C3=22uF 25V
IC1=4081
Q1-2=BD679
D1……5=3mm Red LED S2=SEL 1X6 step
D6……9=1N4148 S3=1X2 mini switch
D10-11=3mm Green LED

120 W audio power amplifier

This is Super Bridge 120W Power Amplifier by IC BDX67B for you as the amplifier circuit using the integrated circuit. Can not be circumvented, because this circuit wattage 120W delivers approximately 2 ohms.

View circuit and PCB where the circuit will think an important equipment used to be.

Must use the power that fits around the +40 V and-40V when the current 4Amp.

Besides the need for a heat sink with a format suitable IC BDX67B and Q1-Q4 BC556A, BC548 to the track all to see. Build easy penalty not paint anything. Ask a fun friend Power Amp Super Bridge 120W by BDX65B you sir.