Power Amp-TDA 7294

Welcome back to Free Circuit dot com again,Today ,I would like to present a small audio amplifier circuit with TDA7294.

You can follow by PCB thus as my post.

The described circuit uses two TDA7294 for use in stereo (2 x 80 watts) and bridge mode (1x 180 watts), configure this setting only four drivers.

To facilitate the installation of each fuel. The performance is a kind of symmetry with a simple bridge rectifier 6A, and two large electrolytic capacitors, which 10000μF 22000μF/50v. This power supply for two modules. The processor is recommended 22-0-22 to 28-0-28 / 5 A, depending on the quality of the transformer is at least 6 amps is recommended.

Parts Layout PCB

Amp TDA7294 PCB

The TDA7294 is a monolithic integrated circuit in MULTIWATT15 package for use as audio class AB amplifier in Hi-Fi field applications (stereo, powered speakers, car, high-end TV) is provided. Many thanks to the wide range of voltage and current capacity he is able to offer the highest property taxes in both 4Ω and 8Ω, to offer even in the presence of poor supply regulation, with the rejection of high-voltage power supply. The built-in mute with delay sounds easier to avoid the remote mode off.

preamp power supply

This is IRRESPONSIBLE and DANGEROUS!!

Welcome back to Free circuit dot com again,today i would like to present the preamp power supply circuit.

this circuit is small and easy to assembly,we will use IC regulator 7915 and 7815 for main control voltage.

About all capacitors are filter noise and frequency.

We will take diodes to allow an electric current to pass in one direction (called the diode’s forward direction), while blocking current in the opposite direction

Microphone preamp circuit

Welcome back to free circuit dot com ,today we have amplifier for microphone with transistor number BC549,BC547 for drive signal.

As this is a simple microphone preamplifier circuit between microphone and stereo amplifier can be used.
The circuit amplifier microphone suitable for use with a normal stereo amplifier line / CD / aux / tape inputs.

The microphone preamplifier can be both dynamic and electret microphone inputs (preamplifier provides foe electret microphone elements). The idea of this circuit is provided that the design as easy as possible for easy build.
Which was my goal when I make a simple external microphone preamplifier for my mixer needed. The behavior of the circuit is nothing better, but with many not so serious projects are used.

Differential Amplifier circuit

Welcome back to free circuit dot com,today i have true balanced input differential amplifier circuit  , So far we have only used one terminal of the operational amplifier inputs on the amplifier or the “reversal” or “non-inverting” input to a single input signal to the other input connected to the mass increase. But we can also receive signals from both inputs at once to produce another common form of op-amp circuit called a differential amplifier.

   Basically, as we saw in the first tutorial on operational amplifiers, the amplifiers are all “difference amplifier” because of their input configuration. But by connecting a voltage signal proportional to an input signal and another on the other input of the resulting output voltage to the “difference” between the two input signals V1 and V2. Differential amplifier then the difference between two voltages, this type of circuit strengthened doing a subtractor, as opposed to stating amplifier input or the amounts that the input voltages. This type of operational amplifier circuit is commonly known as a differential amplifier configuration is shown below:

100W amp MOSFET Print Layout

This week we had the same issue of For today, I bring the audio amplifier circuit 100w Mosfet IRFP250N same number.
But I have no schematic to PCB and accessories print layout of a PCB, which can be used immediately.
For a list of devices. I have already mentioned in accessories print layout.
You can supply them all.
The power supply 50Vdc.

We have the PCB thus as picture below.

100W MOSFET PCB

300_watt_MOSFET_real_HI-FI_power_amplifier

300W MOSFET hifi is real genuine passion for excellence hifi My advanced in the past 40 years on the development of sound sonically superior amplifiers to the highest standards, that’s life.

I’m sharing my experiences on the RAS 300 with other fans my passion for perfection.I designed this minimalist amplifier are committed durable, easy to use and offers the same high-fidelity equal to the original source of these partnerships and would only be with other high quality amplifier products recommended.

When I made ​​this amplifier design, my goal is a product that is best suited to provide for the reproduction of complex music and speech signals was capable of creating. Although I pointed out a high electrical properties, the key requirement to achieve a superior sound to hear, vibrant sound stage and excellent sound clarity.We have a componact print layout thus as below.

300_watt_MOSFET_real_HI-FI_power_amplifier_layout

Although the average hearing level is usually less than 10 watts, my approach to an amplifier to reduce with enough reserve capacity to create a design, but bias for class A in the average volume of crossover distortion to extremely low levels .

This is PCB for the project.

300W PCB

There is a capacitor in the signal path, improving the precision of the tonal characteristics of instruments and voices clearly.
The RAS 300 is almost zero phase distortion, far above the audible range, resulting in a perfect overall resolution and color tone.

protection output of amplifiers

The short circuit proof outputs of amplifiers and speakers, throw some interesting elements, such as the isolation of the speakers from the exit of the amplifier, when is a constant tension presented abandoned or if the heatsink temperature rises excessively, the simultaneous and delayed connecting speakers to the amplifier so until we stop them, the familiar sounds of the charge – discharge of capacitors of the supply.

It ¡s is formed by a binary comparator [IC 1], the transistors Q1-2 and preliminary LED D5-6. The supply of the circuit can have a positive stress [point A], especially the food that is on the D3 and R17, the 15V + stabilized.

Electronic Part List

R1-2=27 Kohms
R3=1.4 Kohms  
R4=1 Mohms  
R5-14-17=3.3 Kohms  
R6-7=100 Kohms  
R8=47 Kohms   
R9-11=120 Kohms  
R10=470 Kohms  
R12=15 Kohms  
R13=1.5 Kohms
R15=4.7 Kohms
R16=33 Kohms
R18=1.5 Kohms 5W
C1-2=100uF 63V
C3=470nF 100V MKT
C4-5=47uF 25V
Q1-2-3=BC337
Q4=BC639
D1=1N4148
D2=1N4004
D3=15V 1.5W Zener
D4=1N4002
D5-6=LED
RL1=24V Relay 
RTH=KTY81-122
IC1=LM393

Point B is one of the secondary coil of the main AC-connected transformer. When the power switch of the AC main line, then an AC voltage (secondary coil of the transformer), is shown in section B, is it? D2 from the negative voltage is recovered and deliver them by R9, cut the Q3 of this year and start charging the C4-R10-11. As long as the last time that the charge on the capacitor, the input [+] IC2B comparator is found in small amounts in proportion to the power [-]. The output of IC2B has a low level, so Q4 will remain in the Cutt off and stay ahead of the RL1, which he D6. Only the C4 is charged, the situation changes in the IC1B, RL1 is activated, the speakers to the output of the amplifier, the D6 it out. If it’s interrupted, the process is reversed, and the speaker without breaking pass interference.

If the circuit during the work, the problem of continuing tensions in the output of the amplifier presented in the RL1 and protects the speaker. This is done using the Q1-2. The acoustic signal from the amplifier output, led to point D, the alternative tensions led to the bottom of the C1-2, which is a non-polar capacitor. Continuous voltage that is greater or less than 1.7 V +? 4.8V, immediately activates the Q1 or Q2 of each. With the activation of the transistors of the input level decreases [+] by IC1B, so turn off and RL1. Another section of the protection for us, the heat protection.

This is using the temperature sensor of RTH, the resistance of the PTC (positive temperature factor) has is found and placed back over the heat sink, where the transistors are found. The price to increase with temperature, the potential of the input [-] by IC1A, goes up to the level of input [+], which is determined by the voltage divider R2-3 determined. Once the level of the input [-] are higher than the level of input [+] IC1A exit again at a low level, and the compelling IC2B to change the situation, turn the RL1 and put the D5, which show the thermal protection. The circuit is above the current designation of the thermal protection 70? C. If it? S instability presented in this phase, the effect of RL1 should be changed from the R4, with other smaller prizes. The circuit was in the magazine? Output? 12/95.

Power supply for amplifier 100W circuit

Wecome back to free circuit dot com,today we have power supply for your audio amplifier with 100 W V-MOSFET.
The proposed power amplifier for 100W V-MOSFET is what appears in the above figure. It has separated supply for the various stages of supply, output stage, stage driver, power amplifier and phase protection. Anyone who wants can remove parts or add a power supply for each channel, separating completely the channels between them. Attention should be given to ground loops. For anyone who does not use the preamp circuit and protection can suppress the corresponding winding.

Out Voltages For Power Supply
+V1=+60V -V1=-60V
+V2=+12V -V2=-12V
+V3=+65V -V3=-65V

Electronic Parts List
C1….4=15000uF 100V
C5-8=2200uF 25V
C15=33nF 630V

IC1=7812
IC2=7912
C6-9=100nF 100V
C7-10=47uF 25V
C11….14=2200uF 100V
BR1=Bridge 250V 25A
BR2=Bridge 250V 3A
BR3=Bridge 250V 3A
T1=220V / 2X43V AC – 250VA
/2X15V AC – 20VA
/2X46V AC – 40VA
S1= 2X2 switch 250V/10A
F1=Fuse 2A slow

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.

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.

250W MOSFET Amp circuit

Today,We would like to present For you, the power amplifier circuit do now, the price reductions.

be used to listen to the music to play indoor celebration. I begs for to advise this circuit. What I am sure it is of good quality does not play well any expensive stereo system. The circuit, when you consider good.

I think you want to use the appearance of the amplifier circuit with MOSFET MOSFET General, some of the J49 and J50 and K134 or K134.

They are more expensive than necessary. We select a few to use the outcome of the number J162-K1058.

Whose price cuts, much more. Side effects other property otherwise. By canning are usually about 88W for 4 ohm speakers and 55W for 8 ohm speakers.

It can meet the frequency or frequency range 20-50000Hz, and the crazy low THD 20Hz-20kHz 0.05% flow. It is the prominent peak, the high frequency requirements.

Thus as below show you in PCB,Part Layout,Real Assembly.

250W Amplifier MOSFET PCB

250W Amplifier MOSFET Part Layout

Electronic Part List

250W amplifer MOSFET Show case

ApeX B500 Amplifier Circuit

Today,We have high power amplifier circuit of ApeX that you know this brand name.

B500, the B250 is based on a number of benefits, and the limiter circuit, schematic and PCB for the same use with B500 and three pairs of + /-65V rails get B250 add.
 You need 500W, 12V to + /-55V DC / DC converter and you can use B500 Auto 2 ohms.
 Director is separate circuit and amplifier can be used to get with every class H amplifier classAB.
 B500 and H900 not step B500 is classAB driver amplifier is Class H and H900 integrited stage driver amplifier.

 If you are found in , we fixed the problem. I was too tired when I measured the track and I have an old 24V fan, and for some reason does not change its speed when the circuit was 24V. Anyway, I’ve now finished for another security, and it works very well (I think). Here are PCB and electronic components layout:

ApeX Audio Amplifier Component Layout and PCB

 For this circuit 625mV. at BD241C at 25 degrees C, gets fans 12V
 If it falls to 440mV, 21V fan gets (I do not know why not 24?) At this point I could barely touch BD241C
 340mV on the protection of LED lights and the relay.
 If the component cools, the relay again.

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

bipolar 300 w circuit

Note that the specification for this amplifier has been extended and now for high continuous power into 4 ohms, but you have to go to the extreme with the heat sink (fan is highly recommended). It was originally designed for “light” intermittent operation, the binding of a subwoofer system (- see project page for information on this route as the ELF-principle) determined. Where continuous high power is needed, there are 4 output transistors recommended wired the same way as Q9, Q10, Q11 and Q12 and the use of 0.33 Ohm emitter resistors.

Output power into 8 ohms is usually more than 150W (250W for ± 70 V supply), and it can be without full power transistors used in an 8 ohm all day, every day. The additional transistors are required only if you want to the same max power at 4 ohms! Think not even asked about the use of supplies of ± 70 V, and bothered me if it’s okay – it’s not!

The circuit is shown in Figure 1, and it is a fairly conventional design. The connections are for internal SIM card (published elsewhere on the project pages) is provided for filtering and RF protection (R1, C2) is provided. The entrance is through a bipolar 4.7uF cap, as this much capacity in a small format. Because the impedance is little or no degradation of the audio clear. A polyester cap can be used if you prefer to be – give 1uF with nominal impedance of 22k, a-3dB frequency of 7.2Hz, which is quite low enough for a sub-group.

300W bipolar amplifier PCB

The first stage is a conventional long-tail pair and uses a current sink (Q1) in the emitter circuit. I decided to use as a current sink to ensure that the amplifier would quickly on demand (and distance) to stabilize the power to convert eliminate the dreaded “blow”. The amplifier is actually quite stable at operating conditions with as little as + / -5 volts! Also note that connections for the SIM card (Sound Monitor Special), representing an average better than conventional clipping ads. See the project pages for more information about creating a SIM circuit. If you think you do not need the SIM, let R4 and R15.

The class-A driver is again conventional, and uses a stabilization Miller cap. This component requires either a 500V or a ceramic device for polystyrene are the best linearity. The tax collector is the bootstrap principle rather than an active current sink, because it is cheaper and very reliable (except, I love the bootstrap principle is

 All three driver transistors (Q4, 5 & 6) must be on a heat sink, and D2 and D3 should be a good thermal contact with the driver heatsink. Otherwise, the result is thermal instability and the amplifier will fail. For some reason seems to be the last statement for some people to cause confusion – see the picture below and you will see the small heatsink, 3-driver transistors and a white “blob” (only for the electrolytic capacitor on the left) that the two diodes to the heat sink with thermal paste down.

C11 is not on this list, so do not bother looking for it. It was “lost” if the schedule was created, and I did not notice until someone asked me where and what it should be. Sorry.

It is in the final stage that the performance of the amplifier is revealed. The most important result is related to many of my designs, but with a higher level than normal for the “sender” resistors (R16, R17). The voltage across these resistors is then the current basis for the main output devices are used in full Class-B are available. In some ways this is a “bad man” version of the famous Quad current dumping circuit but without the refinements, and in principle is the same as in the equally famous Crown DC300A power amps used.

Although I have shown and MJL4281A MJL4302A output transistors because they are new, most manufacturers feel that they are not as readily available as they should. The alternatives are MJL3281 / or MJL1302 MJL21193 / MJL21194.

Note: It is not possible to recommend a Toshiba transistors, since they forged the most of all. The 2SA1302 and 2SC3281 are now obsolete – if you find them, they are almost certainly wrong, because Toshiba does not have this equipment since about 1999 ~ 2000th
Use a standard green LED. Do not use high brightness and other colors because they have a slightly different forward voltage, and this will drop the current functioning of change – this may be a miniature type, if desired. The resistors are all 1/4W (preferably metal foil), except for R10, R11 and R22, the 1W carbon film. All low value resistors (3.3 ohms and 0.33 ohms) are 5W WIREWOUND types.

Because this amplifier operates in “pure” class B (something like a contradiction in terms, I think), the high frequency distortion is relatively high, and may not be suitable for high-performance hi-fi. is the low end of the spectrum, much negative feedback and distortion is actually pretty good, at about 0.04 kHz to% 1. My first tests and reports of others show that there are no audible artifacts at high frequencies, but remains the recommendation.

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

1KW_MOSFET_AMPLIFIER CIRCUIT

Welcome to free circuit dot com ,Today i’m still present the audio amplifier circuit ,I like the supper amplifier .

So,I would like to show you the 1000Watts  MOSFET amplifier circuit for your build sound system.

Click the picture left side to open the Circuit in PDF file.

I include full schemaatic chart and film; pattern of the 1000-watt amplifier and a step by step instructions for setting the construction of the amplifier is a true full 1000 watts per channel.

 I have been building and playing very well goood can drive a 18 Bring with inch subwoofer dual magnet high performance at UA smooth clear and crisp sound that I used for outdoor event and mobile services when building you will, said this amp I can only contact me gave my email Mail on how to get this project … I assure you his powerful …. You could, but I have to return it a full program of 20 band equalizer can be difficult to find on the net …

Class_AB_TIP3055-75W Circuit

Welcome back to Free circuit dot com,Today circuit ,I will show you with 75Watts amplifier does not claim “state of the art”, and in fact the basic design is now more than 20 years old. It is a simple amp to build, uses standard parts and is stable and reliable. The recommended design is a slight adaptation of amp I originally designed many years ago, hundreds were built. Most of them were as small PA or powered instrument amplifier, but many also found their way into the home of hi-fi systems. The amplifier is capable of driving 4 ohm, but It begins, however, the limits of the transistors, even when used at 4 Ohms found very few errors.

The Circuit
Note that no output short circuit protection, so that when the speakers are shorted, while the amplifier is working (with signal), there is a very real danger that the transistors are destroyed.

Since this amplifier has been built commercially, the savings were worth the risk – most of these amplifiers were installed in the speaker box, have so short was probably not (unless the speaker voice coil a few times short-circuited). be used because of the cost of the equipment (at least), it is cheap to repair an amplifier, even if you manage to blow up.

Class AB TIP3055 75W PCB

   
Feature of the amplifier are as follows …

Sensitivity for 74 Watts output power – just under 1V (1V is 75W)
Gain – 27 dB
Frequency range (-3dB) – 10Hz to 23kHz @ 1W
THD at 1 kHz – 0.05% (maximum typical)
Open Loop Gain – 125dB (no load), 80dB (8 Ohm load)
Input Impedance – 22k ohms
DC-Offset – less than 100 mV (<20 mV typical **)
Noise – <2 mV at the output (-80dB unweighted ref 50W)
Changes to the original design …

Reduced the value of the Class-A base resistor 560 ohms **
Increase the value of the bootstrap capacitor 100uF
Reduced stabilization cap 100pF (220pF they are used)
Added the output coil and the damping resistor (see News)
** It is conceivable that a number of transistors can, not the value of 560 ohms is correct. If it is found, you may need “fine tuning” to maintain this resistance at least DC offset. If you really wanted, you could even use a potentiometer (2k), and set it for minimum DC offset. It is best to wait until the temperature stabilized first, but it should not even change much.

Picture below show assembly layout

Class AB TIP3055-75W Layout

Apart from those changes, the amplifier is almost original, with a + /-35V (open circuit voltage) delivery, as stated, will give 70W into 8 ohms very satisfied. In their lives, many of the above mods were anyway, do it because I could never find the wiring diagram when I needed it, it was often so I went along! It is an honest testimony of the resistor and capacitor amplifier that various substitutions can be made, and it still works well.

The noise and distortion figures are a bit pessimistic – there is so little distortion at 1V (or 20 for that matter) that my rate of deformation has great difficulty in a readable measurement. The oscilloscope output indicates that most of what I see is noise – the integration of the output (do my ’scope can) to eliminate the noise reveals little at all.

10W Class A Amp with K1058 Circuit

Welcome back to Free circuit dot com ,Today ,We have small amplifer circuit with 10Watts ,Left Circuit is show one channel ,but I make PCB with two channel(stereo) . 

The 10W Power Amplifier OCL Mosfet K1058 is easy to build,simple circuit to develop and very inexpensive.
This circuit use Power Supply +24V -24V >2A. For the MOSFET K1058 must be mounted on heatsink.

About all resistors 0.5W unless marked.

You can be directly connected to DVD players, tuners and mp4 player.
We have PCB and accessories layout for you easy build.
The PCB has not bug as we had verify and builded completely thus as picture below.

Mosfet Amp K1058-30W CL A PCB

Mosfet Amp K1058-30W CL-A Layout

 

50 watts Amplifier circuit

Amplifier circuit today! ,I got the circuit from japan forum which have good detail both circuit diagram ,PCB,part assembly,layout and show case in completed set that you can make with this information for 50 Watts Power Amplifier.

could you read specification thus as below.

Performance
Output Power 50 watts into 8Ω 70 watts into 4Ω
Music Power 77 watts into 8Ω ;105 watts into 4Ω
Frequency response -1dB at 14Hz and 70kHz (at 1W- see Fig.1)
Input sensitivity 0.875V for 50Ω into 8Ω
Harmonic distortion <.05% from 20Hz to 20kHz; typically <.003%
Signal-to-Noise Ratio -114dB unweighted (22Hz to 22kHz); -119dB A-weighted, both with respect to 50W into 8Ω
Damping factor >140dB at 100Hz & 1kHz, with respect to 8Ω and without PTC thermistor
Protection fuses plus “Polyswitch” PTC thermistor .

50 watts Amplifier PCB

50 watts Amplifier componence layout

50 watts amplifer real assembly

50 watts power supply

Power supply wiring

Pre-tone stereo IC NE5532

Welcome back to Free Circuit dot com ,Today,I would like to present sound controlled circuit , If you want the Pre-Tone Control Stereo track as well. I get for to advise this circuit. Because building the IC NE5532 and of high quality, very reasonable price. This circuit is the perfect bass – treble and fine the loud sound – light. Nice that the sound is all finished equilibrium. You can make your skills. If you try to relax Sir already.Invite circuit construction.
Thus as below is PCB

PCB of Pre Tone Control Stereo

Circuit operation
The circuit has two functions: level attenuation and inverse RIAA equalization. The signal attenuation is needed to convert the 500 mV signal to 2.5 mV signal. The inverse RIAA equalization is the frequency response of the system is also required for flat (same equalization that the music is, vinyl is transmitted in the studio). The photo shows the hit list of the ideal frequency response inverse RIAA filter:

Phono line adapter circuit

RIAA equalization, which show the high pitch noise suppression and maximize bass in the phono playback. The audio material is leveled to rocorded record before, so that the frequency response of the entire chain of the mixer to your speakers flat frequency response.

Nowadays phono inputs are largely unused because record players are still rare. This circuit is a simple converter for line-level signal (0 .. 1 V) in the phono input levels (0 .. 5 mV), making it possible to use these funds as additional line input can. This circuit is the level conversion, impedance and inverse RIAA equalization.

Component list
C1-C4   1 nF
R1    1 Mohm
R2     82 Kohm
R3   1 kohm
and two RCA connectors

The photo below shows the schedule of a channel. The other channel (stereo) is identical. The circuit is so simple that it is easy to assemble just by soldering the components and update a small metal box with the RCA audio jacks.

This circuit is a simplified version of the circuit in Elektor published (T. Giese, pick-up line-level input, Elektor, December 1995, page 99). The basic idea is the same circuit, but my circuit is simpler and do not use high-precision parts. The show is not the same, but I think this circuit is still 5% of the components is suitable for many purposes.

Adjusrable60 Hz filter Circuit

     Regarding this circuit has three change-able notch filters configurations are display .
You can take to used in your small pre-amp or amplifier circuit to filter out any HUM for 50 Hz ( European ) or 60Hz .
With sustituting the capacitors values in the bridge other frequencies can be apply.
About all IC op-amps configuration requires a +/- voltage supply which can easily provided with a voltage divider made of 2 each 100K resistors and a 10 uF filtering capacitor connected from ground to the negative rail . Any op-amps such as the LF353 , TL071, LM308 ,
They can be used and supply from 9 volt battery or other voltage up to 30 volts can be used .

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

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.

mic preamp low noise circuit

Simple mic preamp circuit, which is very low noise. In the circuit diagram in the design of circuits that consist of a combination of differential pairs of transistors with a common mode (floating) gain control connecting the body of the couple.

several pairs of 2N4403 and more than one transistor BC549. In other circuits, in and out and therefore requires a balanced to unbalanced buffer to generate the appropriate output for the next phase of the signal reception channel mixing.

 This step is provided by the gain high performance differential op-amp, which can be a TL071 or similar IC of your choice. Stage has a gain of six to 15 dB and maximum input level is set at about 1.5 volts rms before clipping. It’s the same thing with an SPL of 150dB typical through the microphone.

The operation of the input stage circuit is configured for at least the noise and not to approach the IC.  There are some special ICS can be used for the mic pre amplifier, circuits behave like that, except in a single chip manufactured.

All components must be available, except for 10 k ohm pot for gain control. This should be an inverted cone register – or if you do not use multi-position switch with a gain of 6 dB to 60 dB to cover the range of circuits. Make sure you take a break already. The / -15 volts is too high, should be regulated and low noise.

If the voltage regulator usually used ICS advises me to mount a post-filter consists of a 10 ohm resistor and a capacitor 470 UF to remove any noise generated in the ICS. A 100nF capacitor (C6) should be installed as close as possible to provide the op-amp pin – a ceramic cap is recommended to cut the best performance at high frequency.

mic preamp circuit

One pascal is the amount of pressure generated by the intensity level of 94 dB (94 dB SPL as written). For example, an estimated sensitivity of 20 mV / Pa tells you when the sound of 94 dB SPL hitting the microphone that produces the output voltage of 20 millivolts.
This simple design is very low noise, for example, BC549s 2N4403 and more linear than a single transistor.

The circuit is differential in and out, and therefore requires a balanced to unbalanced buffer to give a suitable output for the next phase in the channel signal mixer.

This is provided by the differential gain stage op-amp is high, which may be a TL071 or similar IC of your choice. This phase has won six or 15 dB, and set the maximum input level to about 1.5 volts rms before clipping. This is equivalent SPL 150dB with a microphone is more typical.

Preamp tone control circuit

The preamplifier circuit is shown in the figure has some interesting features that separate it from “normal,” assuming there is such a thing. The circuit is built by a TL072 amplifier. This is a simple design and provides excellent tonal range. The gain structure is designed to provide a huge amount of profit, which is ideal for guitarists who want to sound completely distorted “fat”. This is an image of the circuit.

The preamp uses a dual op amp that amplification only. The single transistor is an emitter follower, and maintains low output impedance after the master volume control.

As shown in the figure, with a classic guitar input, you can get very big overdrive sound by winding volume, then setting the master to an appropriate level. The frequency response is deliberately limited to prevent extreme low-end plate, and cut highs to help reduce noise and limit the response to the normal requirements for guitar.

If you use the TL072 op amp as shown, you can see that noise is a problem, especially at high gain with lots of treble boost. I strongly suggest to use an OPA2134 op a high-end audio, it will very probably the quietest guitar amp you’ve ever heard. In any gain setting, noise is more than the guitar pickup to the sound of the amp and pre prototype circuit used carbon resistors.

stereo amplifier circuit

The benefit of low cost integrated circuit is determined internally, so that not less than 34 dB (50 times). 

A single phase input allows input signals referred to ground. The result is automatically self-centering to half the supply voltage. The output is short circuit proof with internal thermal limiting. With a maximum output of 15 volts and a load of 8 ohm, the output is about 1,5 Watt per channel. The input stage can be used with the signals from 50 mV to 500 mV rms. If the amplifier should be used with a source other than a personal stereo, as a turntable and an electric guitar, a certain type of preamplifier is required. A circuit is adequately represented. In this circuit is two LM380 operational amplifiers configured as input amplifiers. 

phases contributing to refer to a common point of half the supply voltage.

This trend comes from a voltage divider formed by RI and R2, two resistors of 2.2 k  ohm The gain of each of the LM380 set at 21 for input resistance (R9, R10). The input capacitors, C1 and C2, used to filter the dc component of the input signal.

1Watt RF signal amplifer circuit

Regarding the circuit is a universal 1 W. RF signal class C amplifier which is ideally suited for reduce to low power FM transmitters.

The Input much be least at 100mW for achieve 1Watt output. This is recommended to enclose the amplifier in a metal case.

Part List

Q1 Transistor: 2N5109, MRF227, 2N4427, 2N3866
Voltage Supply: 12 – 15V

UHF TV amplifier Circuit

This UHF broadband amplifier (Ultra High Frequency Amplifier) is a total win 10-15 dB 400-850 MHz frequency range, so it can be used if the TV signal is weak.

This UHF-TV antenna amplifier to work properly you need to cut parts of the pins as short as possible. C1, C2, C6, C7 SMD type (surface mounting). This TV antenna amplifier or UHF broadband amplifier is built in a metal box and then connected to a TV near the antenna.

Power supply is a simple 12V stabilized source. TV antenna amplifier can be connected directly to the power supply via coaxial TV antenna, but you will need 10 – 100UH coil is a food bar. TV UHF amplifier connected through a small coupling capacitor.
Adjustment is easy, that P1 in the middle and adjust it until you get the best TV picture quality.

29 MHz-Amplifer Circuit

In the high frequency amplifier Ruhestromein is an emitter-follower transistor, which corresponds to a bias current of a control input voltage external input directed to a base of the transistor connected gain. The transistor for current control connected in series with the emitter of the transistor to bias supply, and avoids electrical current corresponding to the control input voltage. Electric power under control procedure input voltage flows through the first transistor for temperature compensation. Electricity equivalent electric current through the first transistor for temperature compensation flowing through the transistor for current control.

50mW Audio Amplifier

Here’s a little audio amplifier similar to what you might find in a small transistor radio. The input stage is that the voltage is equal to two complimentary transistors which are biased slightly distorted in the leadership that the split between the diodes. Used 3.3 ohm resistor in series with the producers of the transistors to stabilize the bias current, so it does not change much with temperature or with different transistors and diodes. Since the bias current increases, the voltage between the emitter and base decreases, a heat pipe. Input impedance is 500 ohms and the voltage gain is about 5 to 8-ohm speakers connected. Voltage on the speaker is about 2 volts without the distortion and power is in the range of 50 mW. Higher voltage and adding a cooler, the more power output transistors. Circuit draws about 30 mA from a 9-volt supply.

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

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

Switching capacity of 386-lm-circuit with a PNP type transistor for audio with a receiver gating COS / logical line horn. Wilson has used the brand’s original two-way VHF radios that approach. Another method involves muting (primary) shunt volume pot wiper.

audio amplifier with LM386

The diagram shows an initial stereo headphone amplifier, you are welcome to build a single course, SM-386-audio circuit. The package contains the download full-screen configuration option EQ. Jumper several options you can adjust the frequency response as shown below. The EQ gif image below is the much lower resolution and reduce the actual text Download gif provided.

Although the circuit shown works with 6 volts DC, modern lm-386 packages and can operate with voltages of up to 9 hours to 12 hours volts DC. Make sure when you order the chip, or take the maximum operating voltage is 9 VDC. Some suppliers are “sub” package, the lowest voltage in your order, if you say something.

Another idea is to drive SM-386 to a high frequency audio source, such as audio oscillator circuit 555 on the healthy side. The audio output of the LM-386 and can be adjusted to filter DC. Quite nice, if you’re negative power of a poor man must be based on a route. I used this idea in the era of the late 1970s, the computer circuitry to generate a negative supply rail to a former type is EPROM.

This download file is in zip format, but you can size smaller and a gif file image resolution (see above) on this page with the description. Feel free to e-mail if you have any questions.

The amplifier is very easy to get on the board, and an innovative tone defeat. Rather than disabling the sound system completely, they are massively de-sensitized, and defeated the  have a maximum range, . This can be increased if desired, so that you can have two settings of tone, a rising standard of 10 dB and a cut and the other with a very subtle 3dB boost and cut – that’s enough (surprisingly) a very minor adjustments to the way you need for day-to-day hearing.

Otherwise, the design is fairly conventional, with a great advantage over other models that require almost no cable. Transfer of the source is as you want – I suggest you bring a rotary switch on the rear of the enclosure, and a shaft extension with the tree in front. This leads to a minimum of wiring and reduces crosstalk from other active inputs.

Picture 1 - A and tone controls

Circuit Description

The input stage is shown with a gain of 2 times (6dB), configure and also acts as a buffer circuit for tone control. The tone control is a fundamental type Baxandall, but the addition of R117, 118 and 119 provide the flexibility and ease of reconfiguration, which is not the traditional arrangement.

Picture 2 - Balance, volume and output stages

R119 is the hard part of this circuit (which is unique, too

- I have not seen before, this technique is used). As it is 100k, which limits the range of tone control to a reasonable + /-10dB. To increase more and cutting, R119 (R219 and receive) can be omitted altogether. Conversely, reducing the value of a small area, will also, with about 6 dB at 20 Hz and 20 kHz to 7.5dB with 22K.

The sound system (and overall) performance is shown in Picture 2 (in increments of 10% of pot), and it appears that the midrange is hardly affected. This is in contrast with the majority of drawings in which the controls are aligned to 1 kHz, and it is a very audible in the media. For those who want absolutely no use of tone controls, I suggest that the  both without tone controls are designed and in line with true minimalist design.

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.

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.

I see in the data sheets that the OPA541 can deliever 5A continuous and +-40V on the supply side.

subwoofer circuit

The OPA549 can deliever 8A, but can only handle +-30V on the supply side.

Here you can opa541bm, simply use a link from the period after the defeat on each chip back 1 / 8 pins on the opa541bm. Will give you 200 watts at 4 ohms
How do I calculate how many watts to deliever at 2ohm, 4 ohm or 8 ohm? V ^ 2 / R = W, but how can I find out how many volts can deliever. You can not deliever as much as the supply, or am I wrong?
Data opa541 “Voltage Swing = Vs-5, 5 @ IA = 5A”

Power @ 4 / 2 are generally of the P = ((I * root2) ^ 2) * R = R. limited 8/4/2 ..

Ipeak = V / R. Irms = Ipeak * root2. use for people with reduced mobility and Irms Vrms.
The first operational amplifier and was impressed with the results. I, however, that a simple circuit, the amplifier was very good. I do not have a detailed opinion on the quality of sound, as I am not an audiophile. If you are looking for a simple amplifier to the first draft, I suggest a “clone of gain.”

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I decided then to a more powerful amplifier with a copy of the operational amplifier OPA541 High Power’m as free samples. I was impressed with the results of this amplifier as well, using, given the poor quality of components I. An image of this amplifier is below.

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Both power amps have been mentioned by my bench power supply for testing positive with a positive bid for the railroad, providing 0v, and the positive power supply and one for the land, 0V and the second negative power supply rail. That led me to + / – 0-30V supply to an amplifier, easily enough for testing purposes.

I then two 15V 5A gives, and uses as above. I’m still in the construction phase power supply for my past. This is a wide range of + /-40V. This offer will be able to provide me with sufficient power amplifier.

It is in the testing phase, I rail UF 4700, found around these capacitors effect at the time of the construction industry. Shortly after the discovery provides two 15v, I found four capacitors 33,000 UF and now I am with two by rail, amounting to 66,000 UF rail. This amount of capacity, in my opinion are much more serious. This is because it consumes more bass, treble, and large capacitor banks to help the capacitors, the required power.

The project has a normal gain entry to the regular “Fender-like set of” full-range control, treble, bass, midrange and volume.

It is also possible for extra high gain jack, the second phase of the tunnel and its own gain control. This gives you, the predecessor of classical singing boogie Quickly.

New design dual-Stage Master is another control, with 3 watts can a child all the way back and still be able to talk about it! 

3Watt Tube Amp circuit

Electronic components

5W Tube Power Amplifier with EL84

And each of you probably know, I’m not a fan of tubes parallel to all.I would be very interested to know the success of an amplifier EL84 September

I thought everyone should know that I did for the beginning of the plan at first this thread and its good work. Most of all values for ressistors and caps I used are fairly similar, if not the same as what is in the map. Although I used a plug in multiple sets of filterstage before taking the state wave diode rectifier sound. In the first test no sound, so I cliped feedback negative lead goes to ground and it worked and I cliped feedback and lead others there was no difference in sound if c is finished. Its units strong enough and a lot of 12 “speaker very clearly.

Here are the results of the test:

B 1 = 331VDC, 262VDC B = 2, B 3 = 235VDC

EL84 = PIN9 = 261V, 311VDC bias pin7 = = 47th, PIN3 = 6VDC

The amplifier has been from 1954 to 1989, when it came out, except that the operation, the average activity for 15 hours a day. It is not present in damages in excess, in particular the replacement of the tubes, capacitors and resistors, caused by natural wear. The fundamental change came with the replacement of a provision of the tube, to restore diodes. There is only one problem, they try to produce the transformer cost, (it is valid for all pipe manufactured), one of the code is there and it will help. It may cost to replace traditional transformer suitable for EL34. Its products they need (it is the force responsible for all districts), sufficient experience and attention to the high voltage electric shock.

35w tube amplifier

 Electronic Parts

R1=470K 0,5W
R13-21=820K 0.5W
R12-23= 180K 0.5W 
R2-5= 2K2 0.5W
R14-22=5K6  0.5W
R3=150K 0.5W
R15-20= 680K 0.5W
R4= 220K 0.5W
R16-19=100K 0.5W
R6-10= 56K 0.5W
R17-18=3K3 1W
R7=3.9K 0.5W
R24=470R  2W
R8= 220R  0.5W
R9= 1M  0.5W
R11= 39K 1W

C2=220pF 600v
C8-9=0.1uF 630V
C10-14=0.47uF 630V
C4-5=16uF 550V
C11-13=25uF 40V
C1-3-6-7=0.1uf 630V

V1=E80CC 
V2=E80CC 
V3-4=EL34

TR1-2=470R  1W Variable (adj. 270?) Rectifier
tube= Z2C

T1=Audio Transformer for 2x EL34 Push Pull