How to make an original sound amplifier - with your own hands. Do-it-yourself sound amplifier: how and from what to build a homemade powerful amplifier. The simplest circuits and methods of building an amplifier (95 photos) Simple homemade amplifier

It will have different dimensions and circuit design complexity. The article will touch upon three types of amplifiers - transistors, microcircuits and tubes. And it’s worth starting with the latter.

Tube ULF

These can often be found in old equipment - televisions, radios. Despite its obsolescence, this technique is still popular among music lovers. There is an opinion that tube sound is much cleaner and more beautiful than “digitized” sound. It is quite possible, in any case, that the same effect as from lamps cannot be achieved by using transistor circuits. It is worth noting that the audio amplifier circuit (the simplest one, using tubes) can be implemented using only a triode.

In this case, it is necessary to send a signal to the radio tube grid. A bias voltage is applied to the cathode - it is adjusted by selecting the resistance in the circuit. A supply voltage (over 150 Volts) is supplied to the anode through a capacitor and the primary winding of the transformer. Accordingly, the secondary winding is connected to the speaker. But this is a simple circuit, and in practice two- or three-stage designs are often used, in which there is a preliminary and final amplifier (using powerful tubes).

Disadvantages and advantages of lamp designs

What disadvantage can lamp technology have? It was mentioned above that the anode voltage should be over 150 Volts. In addition to this, it is necessary to have an alternating voltage of 6.3 V to power the filaments of the lamps. Sometimes 12.6 V is required, since there are lamps with this filament voltage. Hence the conclusion - there is a huge need to use massive transformers.

But there are advantages that distinguish tube technology from transistor technology: ease of installation, durability, and it is almost impossible to damage the entire circuit. Unless you need to break the lamp cylinder to break it. The same cannot be said about transistors - an overheated soldering iron tip or static can easily destroy the junction structure. The same problem exists with microcircuits.

Transistor circuits

Above is a circuit diagram of an audio amplifier using transistors. As you can see, it is quite complex - a large number of components are used that allow the entire system to work. But if you break them down into small components, it turns out that not everything is so complicated. And the whole circuit works almost the same as the one described above on a vacuum triode. Essentially, a semiconductor transistor is nothing more than a triode.

The simplest design is a circuit on a single semiconductor, the base of which is supplied with three voltages at once: from the power supply positive through a positive resistance and from a negative common wire, as well as from the signal source. The amplified signal is removed from the collector. Above is an example of an audio amplifier circuit (the simplest one using transistors). It is not used in its pure form.

Microcircuits

An amplifier based on microcircuits will be much more modern and of higher quality. Fortunately, today there are a great many of them. The simplest audio amplifier circuit on a microcircuit contains an extremely small number of elements. And anyone who knows how to handle a soldering iron more or less tolerably can make a good ULF on their own. As a rule, microcircuits contain a couple of capacitors and resistances.

All other elements necessary for operation are present in the crystal itself. But the most important thing is nutrition. Some designs require the use of bipolar power supplies. Often the problem arises there. Microcircuits that require such power, for example, are quite difficult to use to make a car amplifier.

Useful gadgets

Since we have already started talking about amplifiers on microcircuits, it would be worth mentioning that they can be used with tone blocks. Microcircuits are produced specifically for such devices. They contain all the necessary components; all that remains is to correctly install the entire device.

And you will have the opportunity to adjust the timbre of the music. Together with the LED equalizer, this will be not only convenient, but also a beautiful means of visualizing sound. And the most interesting thing for car audio lovers is, of course, the ability to connect a subwoofer. But this is worth devoting a separate section to, because the topic is interesting and informative.

Subwoofer made easy

Advantages of modern amplifiers on microcircuits

Having considered all possible types of amplifiers, we can conclude: the highest quality and simplest ones are manufactured only on modern element base. A lot of microcircuits are produced specifically for low-frequency amplifiers. An example is the ULF type TDA with different digital designations.

They are used almost everywhere, as there are both low-power and high-power chips. For example, for portable computer speakers, it is best to use microcircuits with a power of no more than 2-3 W. But for automotive equipment or home theater acoustics, it is advisable to use microcircuits with a power of over 30 W. But pay attention to the fact that they need sound protection. The circuits must contain a fuse that will protect against short circuits in the circuit.

Another advantage is that a massive power supply is not required, so you can easily use a ready-made one, for example, from a laptop, PC, old MFP (new ones, as a rule, have the power supply inside). Ease of installation is what is important for beginning radio amateurs. The only thing required for such devices is high-quality cooling. If we are talking about powerful equipment, then you will have to install a forced one - one or more coolers on the radiator.

To ensure high-quality sound of music in a car, a consumer can purchase an expensive car radio and subwoofer. But, in addition, the installation of an amplification device is necessary. In order not to spend money on buying it, you can build an amplifier for the car with your own hands.

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Why do you need a car audio amplifier?

When the sound is activated at full power, car radios begin to produce noises and wheezing that are unpleasant for human hearing. This is due to the fact that the standard amplifier for a car audio system is too weak and cannot cope with the load that is placed on it. Especially if the audio system is supplemented with a subwoofer. Amplifiers can be used to eliminate extraneous and unpleasant noise.

The amplification device should not change the sound; its purpose is to maintain sound quality at the appropriate level.

The Treicer100 channel clearly answered the question of the purpose for which amplification devices are installed in cars.

Main characteristics of audio amplifiers for cars

When choosing a device to amplify the volume, you need to pay attention not only to the manufacturer, but also to the main characteristics.

These include:

device class;
number of channels;
rated output power value;
maximum and minimum reproduced frequency parameter;
device sensitivity;
the amount of harmonic distortion, as well as the noise-to-signal ratio.

Device class

On sale you can find devices of the following classes:

The last two options are more popular, so you should focus on them:

Class AB devices are characterized by high quality output pulses, but a reduced efficiency. As a result, the output power will be low, out of 100 W at the output no more than 50 W. The dimensions of such devices are larger, since about half of the power is released in the form of heat flow, which must be dissipated using radiator devices.
Type D devices do not use powerful transistor mechanisms. But the output power will be higher, and the size of the amplification device will be smaller. The efficiency parameter in D-amplifiers will be up to 95%, but the cost of such equipment is much higher. Using a Class D amplification device will allow the consumer to connect a powerful subwoofer to the car radio.

The Ensemb channel showed practical examples and spoke in detail about the classifications of car amplification devices.

Number of channels

Amplifier devices can have a different number of channels:

Monoblocks or single-channel equipment are used to connect a subwoofer to a car radio installed in the car. Monoblocks may not have a high-pass filter device, but it is important that they be equipped with low-pass filters. The range of playable frequencies in such devices, as a rule, shifts downward, and the maximum power parameter is usually no more than 250 Hz. If you plan to connect a powerful subwoofer, the amplification device should be equipped with an ultra-low frequency filter element, this will cut off harmful and unpleasant sounds. If the standard audio system does not have a bass level control, then the monoblock must be equipped with this function.
Dual-channel equipment is a more versatile type of device. Such amplifiers are used to connect two speakers or one powerful subwoofer using a bridge circuit. The amplification procedure in two-channel equipment is performed in the range audible to the human ear - from 20 to 20 thousand Hz. Such amplifiers are equipped with low- as well as high-frequency filtering devices.
Three-channel devices are used to connect two speakers and a subwoofer. Depending on the manufacturer, such equipment is usually equipped with additional functions for working with subwoofers. As a rule, these are filter elements and bass regulators.
A universal option - equipment designed for 4 channels is usually used to create a complete audio system. This device is made of two amplifiers with 2 channels each, which are installed in one housing. Each device is equipped with its own crossover, which makes it possible to use the equipment to connect with 4 speakers or two speakers and one subwoofer. Sometimes two channels are used to play high frequencies, and the other two are used to play low frequencies.
Devices designed for five channels. Such equipment is used to connect to a subwoofer and four speakers.

Output power value

This parameter is one of the main ones that must be taken into account when purchasing. The output power value represents the value at which the equipment can operate for a long period of at least 60 minutes. To mislead consumers, device manufacturers may include peak power numbers on packaging. This value represents the power that the equipment produces for a short time. But long-term operation at this setting can lead to equipment damage.

The output power parameter is a value inversely proportional to the value of the internal resistance of the installed speakers. If their resistance doubles, the power decreases by 50%. When connecting two speakers to the same amplifier channel, the impedance value will change. If it is necessary to use a pair of channels, you must make sure that the equipment allows such a connection.

Playback frequency

The playback frequency parameter covers the entire playable range of 20-20000 Hz. It is possible that these values may be exceeded, but in fact this does not matter. In single-channel equipment used to work with subwoofers, the highest frequency can be up to 300 Hz. This is enough for high-quality work of the subwoofer; there is no point in losing a higher frequency.

Sergey Lebedev spoke in detail about adjusting the frequency parameter when operating a car amplifier.

Distortion parameter and noise-to-signal ratio

If a consumer values high sound quality, it is important to pay attention to these characteristics. The amount of distortion represents the noise that is introduced into the reproduced pulses. Increased distortion may result in a loss of sound clarity. In this case, the sound itself will be duller, hissing will appear, in particular, with increasing volume.

The harmonic distortion parameter is the ratio of the value of the introduced harmonic to the amplitude of the useful pulses. Providing high-quality sound is possible with 1% harmonic distortion at any frequency. Human hearing will not be able to distinguish harmonic distortion of less than 0.5%, so there is no point in buying expensive amplifiers with a lower parameter.

In addition to harmonic noise, amplification equipment also reproduces random noise; the source can be:

The magnitude of this noise is characterized by the ratio of sound to impulse. This value determines what the noise will be if the pulse at the equipment input is zero. For high-quality sound, this value should be at least 75 decibels. If the car has an elite premium radio, then this parameter must be at least 95 decibels.

Sensitivity

The parameter represents the value of the input pulse at which the equipment allows rated power signals to be reproduced. Machine amplification devices are equipped with control devices, which allows them to be installed on any multimedia systems. If the consumer plans to connect an amplification device to the output of the preamplifier of a radio or other equipment or crossover, one point must be taken into account. The selected device must have the function of adjusting the sensitivity parameter. And the output pulse of the device installed in the chain before the amplifier must be within the sensitivity range of the equipment.

To choose a quality device, you need to make sure that there are protections added to the equipment by the manufacturer. It is desirable that the amplification device be protected from overload and short circuit in the electrical circuit. When purchasing, you need to take into account the size of the equipment. The powerful device is characterized by large dimensions, so before installation you need to think about where to place it. The installation location must be protected from moisture and dust, but have free access of air to cool the radiator.

The Vinokurov Audio channel spoke in detail about setting sensitivity parameters in car audio systems.

The process of making amplifiers with your own hands

It is allowed to connect not only a branded amplifier to the car, but also a device made independently. The assembly procedure is recommended for consumers with knowledge of electronics.

How to make a high-quality amplifier case?

You need to assemble a homemade amplifier after the housing is ready. It must fit all components and equipment assemblies. You can purchase a finished product, but you can build it yourself from plywood. To connect the equipment, it is possible to use a housing from a car radio. The device has the required dimensions and design, and for connection it is possible to convert the connectors for a subwoofer.

The best option is to use a ready-made housing made of aluminum; this material will cool the equipment. When the device operates, all components of the circuit heat up, therefore, if the product is made of wood, the consumer needs to think about high-quality cooling. Active cooling systems are allowed, so installing the amplifier in an aluminum case is the best option.

Radioblogful channel. The soldering video blog described in detail the creation of a housing for an amplification device made of aluminum.

Sound amplifier for subwoofer

Making a subwoofer for a car radio consists of four stages:

Selection or independent development of the electrical circuit of the device.
Performing a task to process an audio signal.
Assembly of the stabilization block of the power electrical circuit.
Assembly of all components into a single device.

Features of the amplifier assembly:

A board is selected that must have built-in overheating protection; all branded devices are equipped with such an element. The microcircuit must be protected from short circuiting. It is possible to add an error detection system to the board; for this, a diode light source is installed. It will blink in case of overheating or short circuit.
Then the consumer draws a printed circuit board; for this, the use of LUT technology is recommended. If you don't have such a printer, you can use a marker with a stroke.
Holes are drilled on the board to install the component elements, after which they are mounted. Before installation, the board is tinned and the elements are fixed on it. It is recommended to cover the tracks that will be used to power the device with solder or solder a piece of wire on them. The solder should be thick.
An electrical capacitor device with a large capacity and the required voltage level is installed in the power supply circuit. The example uses a 16V 4700 µF capacitor.
The microcircuit is installed on the radiator device. It is recommended to use larger radiators than indicated in the photo, or you need to make an active cooling system. This will require the use of a cooler; fans from personal computers can be used.
When the assembly of the amplification device is completed, it is necessary to build a filter element for power supply. It will be needed to connect the equipment to the machine's electrical network.
The inductor is wound with a cable with a cross-section of no more than 1.5 mm2, the procedure is performed on a ferrite ring. The diameter of the latter should be 20 mm, and the number of turns will be 5. It is allowed to use a ring from a PC power supply or a 12-volt transformer device. The size of the element may vary; if it is missing, purchasing a new device is allowed.

Audio signal processing

An adder is used to process audio signals. The device is designed to sum and also increase the power parameter of the audio channel. If one subwoofer is installed in the car, then the unit is equipped with three regulatory elements. One of them regulates the cutoff of audio frequencies, the other controls the volume, and the third is a phase rotator. This allows the speakers and subwoofer to function in harmony with each other.

Features of the adder assembly:

The circuit is based on film capacitor devices. This option is optimal for providing high power and circuits used in machine subs.
It is possible to use capacitor options designed for 100 pf. It is better to use ceramic parts.
A printed circuit board is used to create an adder chip. This option does not require preliminary adjustment and configuration. Printed circuit boards are the most compact.
When performing the assembly, the consumer will have in his hands a block consisting of a filter device and an adder. An amplifier of any power can be connected to such a device.

Adder circuit for amplifier

Assembling the power circuit stabilization unit

When driving at idle speed, the booster device requires no more than 1.5 amperes of current generated by the battery. To prevent battery discharge, a relay with a 12-volt voltage is installed in the car. The current parameter should be 20 amperes. A separate terminal is made to install the relay.

The terminal is connected to a separate contact on the audio system, the output should have a 12-volt voltage. This will allow you to activate the subwoofer with the multimedia complex. Additionally, two diode lighting sources are mounted on the board; they are used to control activation and shutdown. To obtain a bipolar power supply, transistor elements and zener diodes are mounted on the board. To reduce the voltage and stabilize the parameter to 15 volts, integral stabilizer elements are used.

Assembling the stabilization unit on the board

Putting all the parts together

There are two options to assemble all the parts of the device into one device:

Mount all components on one board. After this, they are installed in a plastic case.
Assemble all circuits and boards separately. The elements are connected through electrical circuits. The second option is preferable for novice users. When implementing it, you will still need a housing; it is used to protect equipment from external influences.

To protect electrical circuits from rapid heating, radiator devices are used, otherwise the amplifier may burn out.

Speaker amplifier

To complete the task of assembling an amplification device for car speakers you will need:

computer or laptop;
soldering iron with rosin and tin;
jigsaw;
a piece of plywood from which the body will be made;
adhesive sealant;
ruler;
pencil or marker;
set of terminals and plugs;
woofer;
processing unit;
wire for connecting to the car radio and speakers;
an electronic component that you can make yourself or buy a ready-made version.

Amplifier assembly diagram and step-by-step description of the process

The procedure for assembling an amplifier into a car with your own hands:

At the first stage, preparatory actions are performed. It is necessary to prepare all the elements for assembling the device and think over a plan for carrying out the work.
A ready-made circuit for an amplifier device is being created or searched for. The development of the board is done with similar components as described in the previous section. You can purchase a ready-made board or order an element from a specialist. The microcircuit is selected with protection against overheating and short circuit; holes are drilled on it for mounting the component elements.
In accordance with the diagram, the electronic component is assembled. Capacitor devices, stabilizers and other electrical components are installed.
After assembling the board, the housing for the amplifier is manufactured. On a piece of plywood, the walls, bottom and upper part of the body are drawn using a pencil and a ruler. Pieces of wood are cut out with a jigsaw and fixed together using sealant or self-tapping screws.
A woofer, electronic part, and switching devices are fixed on the device body. All electrical circuits of the speaker system must be tightly fixed in the housing and ensure their tightness in order to prevent the negative impact of external factors.
The amplifier device is being tested. If required, additional adjustments of the car radio parameters are made. At the final stage, the amplifier is installed in the designated place, then the operation of the acoustics is checked.

Circuit diagram of a low-power amplifier device for speakers

Rating of the best amplifiers for cars 2018

Not every consumer is able to assemble an amplification device in a garage. By purchasing a branded amplifier, the car owner receives a guarantee that the equipment will work efficiently, which cannot be said about self-made devices.

Pioneer GM-D8601

The Pioneer GM-D8601 model is made in a small case, which will ensure ease of installation of the device in a car. The single-channel device belongs to category D and is characterized by high stability to low output impedance. This allows for approximately 300 watts of power at 3 ohms. If the resistance value drops to 2 Ohms, then the rated power value will be 500 W. The price of the amplifier is 7590 rubles.

In reviews, consumers complain about an increased harmonic distortion parameter, which amounts to up to 0.5%. In fact, this does not particularly affect the sound quality, since amplification devices are used to work with subwoofers.

Advantages of GM-D8601 models:

high power, which is confirmed by consumer reviews;
the optimal range of reproduced frequencies is from 10 to 240 Hz;
the device is equipped with a high-quality filter element for low frequencies;
small body dimensions;
using the model provides the ability to connect up to four subs;
large outputs for connecting the power supply circuit;
low resistance of 1 ohm.

The main disadvantages include the lack of heat sinks, which will cause the amplifier to overheat, as well as the lack of customization options.

You can learn more about this model from the video on the Autosound Factory channel.

Pioneer GM-D9601

The single-channel model allows you to connect up to four subwoofers, which allows you to squeeze maximum power out of the latter. With a resistance value of 2 ohms, the device can produce up to 1600 W of maximum power. If the operating parameter is doubled, then the peak power will decrease to 1000 W. In the case of the nominal indicator, the operating value will be 800 W at 2 Ohms of resistance.

The Pioneer model GM-D9601 is equipped with a low-pass filtering device that operates at 40-240 Hz. The main feature of a D-category amplifier, whose distortion is no more than 0.5%, is the presence of a remote bass control. This model is optimal for lovers of low frequencies.

Advantages of the model:

availability of short circuit protection;
the power parameter is increased to maximum values;
high-quality low-frequency filtering device;
working with several subs is allowed;
small dimensions of the case, allowing installation of the amplifier anywhere in the cabin;
presence of a regulator for changing the bass volume;
The device consumes a minimum of electricity during operation, which prevents rapid battery drain.

The main disadvantages include the inflated cost, which amounts to 11,499 rubles.

Mystery MR-2.75

The Mystery MP-2.75 model has a low cost, but the power of this amplifier is low. The device is designed to work with a two-channel speaker system. Its use will provide deep low frequencies. Small dimensions allow you to install the device almost anywhere in the cabin. The equipment belongs to the AB category, so it is characterized by increased energy consumption when the radio is activated at full power.

Advantages of the model:

a high-quality two-channel sound system is implemented;
availability of protection against voltage surges and short circuits;
if the connection of the device to the subwoofer or speakers is bridged, then the power parameter can be up to 225 W;
it is possible to adjust low frequencies;
the presence of filter elements for bass and high frequencies;
the harmonic distortion coefficient parameter is 0.03%;
high range of playable frequencies, ranging from 20 to 20 thousand Hz;
an affordable price for many car owners of about 3,599 rubles.

Cons of Mystery MP-2.75:

the rated power value with a resistance of 2 Ohms will be no more than 120 W for one channel;
connectors and plugs that are inconvenient to connect;
high electricity consumption;
minimum settings.

More details about the technical features and functionality of the Mystery MP-2.75 model can be found in the video filmed by the TAZavod 42 channel.

Pioneer GM-A5702

The cost of this device model is quite high - 7910 rubles, but the Pioneer GM-A5702 fully justifies the price. The rated power at a resistance of 4 Ohms is 150 W for each channel. When connecting equipment via a bridge circuit with a similar resistance value, the power value will increase to 1000 W. If this Pioneer model is installed in a car equipped with high-quality acoustics, it will be able to produce deep low frequencies and clear sound in general.

The model works with harmonic distortion, but this parameter is no more than 0.05%. It is possible to independently adjust the bass. As a result of the fact that the device belongs to the AB category, when operating at full power, the load on the battery will be high.

Advantages:

the presence of a low-pass filter operating in the range from 40 to 500 Hz;
the possibility of maximum sound reproduction at a frequency of 70 thousand hertz, sound quality depends on the installed audio system;
the maximum power value at a resistance of 4 ohms will be 300 W per channel;
good value of rated power, ensuring high-quality playback;
the presence of a two-channel system, its implementation at the highest level;
minimum amount of harmonic distortion;
presence of a low-frequency regulator;
compact dimensions of the device.

The disadvantages of the model include the absence of a high-frequency filter device.

Kicx RTS 4,100

This model costs 7,790 rubles. allows you to “squeeze” the maximum out of car speakers and subwoofer. It is possible to bridge the device, as a result of which the number of channels is reduced to 2, but the power value of each will be 190 W. The nominal power parameter at a resistance of 4 Ohms is 100 W for each channel. If the resistance is 2 Ohms, then the operating parameter will increase to 200 W.

In general, the technical characteristics are no different from other models. This device reproduces sound at a frequency in the range of 20-20000 Hz. The consumer has the opportunity to activate the Bass Boost option, which allows you to increase the low-frequency parameter. There is a built-in crossover, and the low-pass filter device is complemented by a filter element for higher frequencies. There is protection against power surges, overheating and short circuits; safety devices rated at 35 amperes are used for protection.

Advantages of the Kicx RTS 4.100 model:

high power value for multi-channel equipment;
small dimensions allowing for simplified installation;
various options for protecting the device from failure;
possibility of amplification of low frequencies;
presence of a crossover;
reduced harmonic distortion parameter.

This model has no disadvantages, but some consumers note a lack of equipment power.

The Team Sound Quality Rtishevo channel provided a detailed overview of the characteristics and features of the Kicx RTS 4.100 car amplifier.

Sony XM-S400D

Consumers trust the Sony brand because this company made a name for itself in the production of audio equipment. The Sony XM-S400D model is characterized by increased reliability and compact dimensions. Users do not like the design of the device, which is made in the form of a regular black box with several outlets on the sides. But this drawback is insignificant, since no one will look at the device during operation.

Installing an amplifier in a car will provide deep and accurate sound, which is due to the presence of filtering devices for all types of frequencies. The rated power parameter is 45 W for each channel, provided that the resistance value is 4 Ohms. If the connection type is bridged, then the power will increase to 100 W for each channel, while the number of channels will not decrease. Features of the device include reduced harmonic distortion of 0.08%. Due to the fact that the model belongs to category D, the amplifier consumes a minimum of electricity during operation.

Advantages of the model:

high rated power;
obtaining deep and clear sound when connecting an amplifier;
the ability to reproduce frequencies over a wide range;
the presence of filtering components that provide high-quality sound;
reliable protection of equipment from failure; various systems are used for this.

Cons of Sony XM-S400D:

lack of ability to adjust low frequencies;
consumers note the difficulties that may be encountered when installing equipment;
high price - 9990 rub.

Complete set of amplifier model Sony XM-S400D

Genesis Profile Four Ultra

This model costs 18,990 rubles. cannot boast of an original design, but it looks quite elegant, which is achieved thanks to the narrow radiator devices installed inside. The maximum power setting can be up to 400 W, which is quite enough to set up a loud audio system. The presence of a fan will provide effective protection of equipment from overheating, and thanks to the crossover, unnecessary frequencies can be removed. The Genesis Profile Four Ultra model is considered the best option for installation in a car where front speakers play.

Advantages of the Genesis Profile Four Ultra amplifier:

increased equipment power;
possibility of functioning with a regulatory device;
using a bass equalizer that allows you to adjust parameters;
the presence of a fan inside the structure;
small body dimensions.

Disadvantages include the sensitivity range. Some consumers note that it is not as extensive as it could be.

Audison SR 4

This model costs 21,700 rubles. It is considered universal and, judging by reviews, has a long service life. When developing the device, the manufacturer implemented a configuration configured for the most commonly used circuit, which will eliminate installation problems. The device is enclosed in an aluminum housing, which prevents physical damage to the equipment. The developer used a competent design in manufacturing, which ensures high-quality cooling of the device. The functionality that this model has indicates the need to install an amplifier on a front speaker system with a subwoofer.

Advantages of the Audison SR 4 model:

durable aluminum case ensuring long-term operation of the device;
the ability to flexibly customize the device to suit specific needs;
ease of equipment management;
effective cooling system that prevents the device from overheating.

Flaws:

the model cannot boast of small dimensions, difficulties arise when installing the device;
no bandpass filter device.

The Avtozvuk channel in the video gave detailed advice on adjusting the basic parameters and tuning the car amplifier after installation.

When I found on Ebay a tiny amplifier “PAM8610 stereo mini class D digital power amplifier board 2 x15W”, measuring 2.5 * 3 cm and costing about 350 rubles, I realized that I simply could not pass by.

It turned out that 2*15W is the only option for 4 Ohm speakers. I didn’t have any of these, so I connected 2 * 10W with a reading of 6 ohms.

Class D amplifiers get a lot of negative reviews from “serious” music lovers, but to my ears everything sounded just fine (and loud!), especially with decent speakers and an MP3 player with a built-in graphic equalizer and various additional settings.

Using an MP3 player also means that there is no need to control the lows, highs and mids through a homemade sound amplifier; all you need is a volume control knob.

Due to the fact that the wiring between the components is very simple, even novice hobbyists can easily assemble this project with their own hands.

Step 1: Let's collect the necessary components

To create an amplifier we will need:

1 pc * plastic box. Mine was approximately 8 * 5 * 2.2 cm in size
1 pc * PAM8610 Digital Power Amplifier Board 2 x 15w
1 piece * 50K + 50K Dual Potentiometer
1 piece * Button for double potentiometer - choose the color to suit your taste.
1 pc * SPDT (Single Pole - Double Throw) switch
1 piece * 3.5 mm stereo jack socket for installation on the case
1 pc * Power jack socket for installation on the case
2 pcs * 10uF 25V electrolytic capacitors - the smaller the better
2 pcs * 2-terminal or 1 pc * 4-terminal blocking screw terminals
1 piece * 3mm LED (any color you like)
1 pc * 4.7K 1/8W resistor (current limiting for LEDs - more details in the appendix)
1 piece * 12V 2A AC adapter (more details in the app)
1 piece * diode 1N5401 or 1N5822 (optional)

In addition, to connect the components you will need a multi-colored stranded (7-core) wire.

I have attached a PDF with a very detailed explanation of each item on the list. I wrote this document mainly for beginners, so if you just want a list of components, then skip most of the document and read only about the AC Adapter - this is very important.

Files

Step 2: Required Equipment

This project keeps the amount of mechanical work to a minimum, so you only need three basic tools. Tools needed for drilling holes and soldering:

Hand drill with a 1mm bit for drilling holes.
Large drill for enlarging holes.
Reamer drill.
Soldering iron 18W - 25W.

The reamer is my favorite tool for making holes in plastic and metal, and I recommend everyone keep one in their toolbox at all times. After making a 3mm hole in the center of the area where the desired component will be located, you take the drill and slowly press it in, turning it clockwise. After every few turns, you check that the component fits into the hole and is securely seated.

Soldering iron. There is nothing new to say about this tool that has not already been described in hundreds of other articles. All you need to know: practice makes perfect. You will be working with a circuit board that has chips mounted on its surface, so be very careful. Avoid splashing solder - one drop can ruin the entire amplifier.

Step 3: Prepare the body

In this step we will prepare the box for installing all the necessary components into it.

Apply clean white tape to the surface of the cabinet where you will be mounting the switches and controls. In my case, I decided to make the front and back panels like real amps and marked where each component would be (see photo).

The sticker allows you to mark the location of all control components and at the same time protects the surface of the case from scratches while you are drilling holes, etc.

Using a 1mm mini drill, drill pilot holes along the marks you made earlier. Next, use a drill to widen the holes by 3 mm (excluding the holes for the speaker connectors). Then widen the holes with a drill (following the tips from the previous part of the instructions). Do not widen the LED hole by 3mm unless you intend to use a larger diameter diode.

You can see the results of the work in the attached photographs - neat holes that do not require further processing.

You can see that all the components are already screwed to the case, with the exception of the speaker terminals, these are threaded through 1mm holes and glued to the case with superglue. The LED simply sits tightly in the hole, but it can be additionally secured with superglue.

Step 4: Connecting the Components

Wiring is very simple. For easy debugging, if something suddenly doesn’t work, I recommend using wires of different colors. For example, red is for positive wires, black is for negative or ground wires, orange is for all right channels, and blue is for left channels. To connect the speakers I used orange for right +, white for right -, blue for left +, brown for left -. You can use your own combination of colors, but try to use the same colors for the left and right channels.

There are just a couple of simple things you need to know about polarity, read the attached PDF to become familiar with this information.

Also take into account that I'm installing everything into a case using it as the top of my amp and the case cover being the bottom. This means that I am working with a mirrored assembly diagram. In real life, all components installed on the left will be on the right and vice versa. Be careful when connecting the speaker wires, if your layout is like mine the left speaker connections will be on the right and the right speaker connections will be on the left. This way, when you turn the amp case over, everything will fall into place.

By looking at the attached photo you can see how easily everything fits together.

Files

Step 5: Troubleshooting and Precautions After Assembly

After you've soldered everything together and before you connect the speakers and turn on the amplifier, you need to do some preliminary tests.

Double-check that the components are connected correctly, or better yet, have a friend do it and make sure everything is connected correctly. A fresh look at the project will help you see what you might not notice after spending hours at home working.

Using a multimeter, at low resistance ranges, check the circuit for short circuits at points 1, 3, 4, 5 and 6:

If you have a short at point 1, then your power adapter will explode as soon as you plug it into the outlet.
If you have a short between the speaker pins or between any pins on points 3 or 4 and ground, your amplifier module will explode. The right and left negatives are not common points, so under no circumstances short them together or connect them to ground.
If there is a short between the left or right channel and ground at point 5, then one of the channels may not work when turned on.
If the short is at point 6, then your power adapter will explode as soon as you turn on the switch on the case.

Regarding the power switch (point 2), if you expect it to be on in the "Down" position and off in the "Up" position, set the switch to the "Down" position and using your ohm-range multimeter, measure the resistance between the two points rations. If you get anything other than zero ohms, the switch is flipped. Loosen the mounting screw and flip the switch 180 degrees until it is in the Up position. Switch it to the down position and check the resistance again. If it is still not zero, then your switch is most likely faulty.

Additional protection. As noted earlier, you can damage the AC adapter if you use the opposite polarity to what your amplifier's wiring is designed for. You can protect yourself by adding one diode in series to the positive connection of the board. The connection diagram is shown in the attached diagram.

In this case, if you connect the adapter with reverse polarity and turn on the device, the diode will not allow voltage to reach the amplifier module. In this case, the LED will also not light up - this will be an indicator to you that the polarity of the adapter is incorrect or the adapter itself is defective.

The only drawback of such protection is that after the current passes through the diode, there will be a slight voltage drop, which is very important if your adapter produces exactly 12V.

I recommend taking both 3A diodes. The difference is the forward voltage drop. If you use a standard 1N5401 rectifier, the voltage drop is about 0.7V, so the available voltage will be 11.3V or less. When using the Schottky Barrier Rectifier 1N5822 the drop is only 0.4V at 2A, so you will have at least 11.7V (which is closer to 12V). Choose one of these diodes depending on your needs. For example, if your AC adapter's current output voltage is 13V (which is entirely possible), then a 0.7V drop shouldn't matter, so you can use the 1N5401.

MAXIMUM DEVICE VOLTAGE: The maximum voltage that the amplifier module can handle is 16V. To avoid damaging it, before connecting, check the actual output voltage of your AC adapter using a multimeter and make sure that it is significantly lower than 16V.

Step 6: Turn on the device

Once you have checked that everything is soldered well and that there are no shorts in the circuit (and also soldered the recommended diodes), you can connect the AC adapter, speakers (pull the entire exposed section of the wire all the way through so that the insulation reaches the clamp) and the MP3 player, lift a little volume level and turn on music. Enjoy the sound.

If you didn't use a diode for protection, there is one more precaution you can take before turning on the power. Keep the +12V wire that goes to the amplifier module disconnected, connect the AC adapter, turn on the power and use a multimeter in the DC range, connect the red end to the disconnected red wire, and the black end to any black connection (ground), check that The voltage reading is positive in the range of about 12V.

Once you are sure that the voltage and polarity are correct, turn off the device, unplug the adapter, solder the red +12V wire to the amplifier module and turn everything on, following the instructions above. You are already on the way to good sound!

Step 7: Conclusions

When I started working on the instructions, I wanted to make everything simple and quick so that every beginner would understand how easy it is to create an inexpensive and small stereo amplifier. As I wrote the article, more and more nuances appeared that I would like to describe in more detail. Instead of pasting all this into the main text, I made a couple of PDFs and attached them to the necessary steps. I hope I haven't crossed the line between informative and boring.

If you are new to electronics and you are going to build your own amplifier, then you should have at least the basic tools such as a soldering iron, solder, multimeter, screwdriver, pliers and wire cutters. Please also read all attached PDF files before starting.

Much of the information is based on my many years of experience in the appliance repair business as well as training technicians for these tasks. It was very difficult for me not to mention all the nuances described, especially due to the fact that most authors do not delve into these problems. For me, this is the difference between the success or failure of a project.

I hope you enjoy everything!

How to achieve high-quality sound of your favorite music? Arm yourself with the necessary knowledge and tools, after which you can assemble a sound amplifier with your own hands.

Which amplifier is better?

There are as many opinions as there are radio amateurs. Basically, the choice depends on the person, so it is very difficult to draw any specific conclusions. Today you can assemble a sound amplifier with your own hands using:

Transistors. They have low power consumption and compact dimensions. They provide excellent sound quality.
Lampah. An old fashioned way of assembling radio equipment. Despite its monstrous gluttony, weight and size, it surpasses semiconductor analogues in sound quality.

Where to begin?

Before making a sound amplifier, you need to clearly understand under what conditions and for what purpose it will be used. This directly determines how much power it should have. In order to listen to your favorite songs at home, a small device that will provide high-quality sound with a power of 30 - 50 W is enough. The situation will be completely different if you need to create equipment for large-scale events. In this case, it becomes necessary to assemble a more complex sound amplifier with your own hands. 200W is far from the limit of power that will be needed during operation.

You should also stock up on everything you need:

Soldering iron.
Multimeter.
Screwdriver Set.
Textolite for the manufacture of microcircuits.
Material for the housing of a future amplifier.
Electrical parts that are indicated in the circuit diagram of the product.
Circuit board diagram of the amplifier selected for assembly.

DIY printed circuit board

Each business has its own subtleties. Making a printed circuit board at home is no exception. It is this that will subsequently become the basis for all further work and will allow you to assemble a sound amplifier with your own hands. First let's look at everything we need:

Textolite with copper foil.
Household iron.
Detergent "Silit".
Laser printer.
Chinese self-adhesive film with backing marking 333.
Drills for making holes in PCB.
A tampon made of gauze and a piece of cotton fabric.

We cut out the required piece of PCB so that there is approximately one centimeter of margin left on each side.
We treat it with detergent until the copper foil turns pink.
We wash the processed board and send it to dry.
We take a piece of self-adhesive of the required size, use glue to glue it with a backing to an A4 sheet, remove the film layer, and print the design of the future board on the polished side of the resulting blank. In this case, the toner supply must be set to maximum.
On the desktop we lay out a sheet of plywood, an old unnecessary book, and on top - a board with the foil facing up.
Cover the board with regular office paper and heat it with a preheated iron. The approximate warm-up time is one minute.
Next, remove the iron and sheet of paper, apply the printed design and smooth it with a swab.
Cover again with a sheet of paper, place the iron on top and wait about 30 seconds. If the surface of the board is larger than the sole of the iron, then you need to iron the entire part evenly.
Remove the sheet of paper and smooth the pattern with a swab for 30 seconds. Movements should be both along and across. In this case, you need to apply a little pressure on the workpiece.
After the workpiece has cooled, carefully remove the backing.

How and with what to etch the board

In order to correctly assemble a sound amplifier with your own hands, it is not enough to correctly draw the board design or solder the wire. You need to be able to efficiently etch all the tracks on the microcircuit.

Ferric chloride has always been used for these purposes. However, this solution is very expensive and is not always commercially available. For this reason, it can be replaced with a homemade solution of copper sulfate and table salt, which are not in short supply. The proportions for the mixture are as follows:

A liter of warm water.
100 g of copper sulfate.
200 g kitchen salt.

When all the components are dissolved, clean and grease-free metal products (for example, a pair of nails), the workpiece itself, a small motor with blades or a compressor from an aquarium are lowered into the container. To enhance the reaction, place the container with the solution in warm water. The approximate time for etching tracks is 25-30 minutes.

Amplifier assembly

The first step that needs to be done in order to assemble a sound amplifier with your own hands is to install all the radio components on the printed circuit board. Particular attention should be paid to polarity here. It would also be worth noting that all work should be carried out with special care and attention. Otherwise, a short circuit may occur, which will lead to inevitable failure of the components of the future amplifier.

After the above procedure, the housing assembly follows. Its dimensions will directly depend on the dimensions of the amplifier board, power supply and the method of implementing volume control and balance between channels. At this stage, you can use a ready-made factory case with some design changes. However, the best way is still to manually make the shell of an electrical appliance. This way you can realize the possibility of creating a unique design. There is also the option of installing a board in the housing of one of the speakers.

Before putting everything together, it is necessary to conduct a test run of the future electrical appliance and, if necessary, eliminate all problems.

The last step is assembling the amplifier, which consists of installing the board, power supply and all other components.

A little off topic

When assembling audio power amplifiers with your own hands, it is not always possible to achieve the desired effect. The secret is that the so-called acoustics are not able to cope with the tasks assigned to them. For this reason, sometimes you have to additionally assemble even the speakers yourself. This approach to the issue will not only guarantee maximum satisfaction of all wishes, but will also help get rid of a separate device by hiding the amplifier in the speaker housing.

In this article we will talk about amplifiers. They are also ULF (low frequency amplifiers), they are also UMZCH (audio frequency power amplifiers). These devices can be made on both transistors and microcircuits. Although some radio amateurs, paying tribute to the vintage fashion, make them the old fashioned way - using lamps. We recommend you look here. I would like to draw special attention of beginners to car amplifier microcircuits with 12-volt power supply. Using them you can get a fairly high-quality sound output, and for assembly, knowledge of a school physics course is practically enough. Sometimes from the body kit, or in other words, those parts on the diagram without which the microcircuit will not work, there are literally 5 pieces on the diagram. One of these, an amplifier on a chip TDA1557Q shown in the figure:

Such an amplifier was assembled by me at one time; I have been using it for several years together with Soviet 8 Ohm 8 W acoustics, together with a computer. The sound quality is much higher than that of Chinese plastic speakers. True, in order to feel a significant difference, I had to buy a creative sound card; the difference with the built-in sound was insignificant.

The amplifier can be assembled by hanging mounting

The amplifier can also be assembled by hanging mounting, directly on the terminals of the parts, but I would not recommend assembling using this method. It’s better to spend a little more time, find a wired printed circuit board (or wire it yourself), transfer the design to the PCB, etch it and end up with an amplifier that will work for many years. All these technologies have been described many times on the Internet, so I will not dwell on them in more detail.

Amplifier attached to radiator

I’ll say right away that amplifier chips get very hot during operation and need to be secured by applying thermal paste to the radiator. For those who just want to assemble one amplifier and do not have the time or desire to study programs for PCB layout, LUT technologies and etching, I can suggest using special breadboards with solder holes. One of them is shown in the photo below:

As can be seen in the photo, connections are made not by tracks on a printed circuit board, as is the case with printed wiring, but by flexible wires soldered to the contacts on the board. The only problem when assembling such amplifiers is the power supply, which produces a voltage of 12-16 volts, with a current consumption by the amplifier of up to 5 amperes. Of course, such a transformer (5 amperes) will have rather large dimensions, so some people use switching power supplies.

Transformer for amplifier - photo

I think many people at home have computer power supplies that are now obsolete and are no longer used as part of system units, but such power supplies are capable of delivering +12 volts through circuits, currents much greater than 4 amperes. Of course, such power supply among sound connoisseurs is considered worse than a standard transformer one, but I connected a switching power supply to power my amplifier, then changed it to a transformer one - the difference in sound can be said to be imperceptible.

After leaving the transformer, of course, you need to install a diode bridge to rectify the current, which must be designed to work with the large currents consumed by the amplifier.

After the diode bridge there is a filter on an electrolytic capacitor, which should be designed for a noticeably higher voltage than in our circuit. For example, if we have a 16 volt power supply in the circuit, the capacitor should be 25 volts. Moreover, this capacitor should be as large as possible; I have 2 capacitors of 2200 μF connected in parallel, and this is not the limit. In parallel with the power supply (bypass), you need to connect a ceramic capacitor with a capacity of 100 nF. At the input of the amplifier, film decoupling capacitors with a capacity of 0.22 to 1 µF are installed.

Film capacitors

Connecting the signal to the amplifier, in order to reduce the level of induced interference, should be done with a shielded cable; for these purposes it is convenient to use a cable Jack 3.5- 2 Tulips, with corresponding sockets on the amplifier.

Cable jack 3.5 - 2 tulips

The signal level (volume on the amplifier) is adjusted using a potentiometer, if the amplifier is stereo, then dual. The connection diagram for the variable resistor is shown in the figure below:

Of course, amplifiers can also be made using transistors, while power supply, connection and volume control are used in them in exactly the same way as in amplifiers on microcircuits. Consider, for example, an amplifier circuit using a single transistor:

There is also a separating capacitor here, and the minus of the signal is connected to the minus of the power supply. Below is a diagram of a push-pull power amplifier with two transistors:

The following circuit also uses two transistors, but is assembled from two stages. Indeed, if you look closely, it seems to consist of 2 almost identical parts. Our first cascade includes: C1, R1, R2, V1. In the second stage C2, R3, V2, and load headphones B1.

Two-stage transistor amplifier - circuit diagram

If we want to make a stereo amplifier, we will need to assemble two identical channels. In the same way, we can, by assembling two circuits of any mono amplifier, turn it into stereo. Below is a diagram of a three-stage transistor power amplifier:

Three-stage transistor amplifier - circuit diagram

Amplifier circuits also differ in supply voltage, some require 3-5 volts to operate, others require 20 or more. Some amplifiers require bipolar power to operate. Below are 2 amplifier circuits on a chip TDA2822, first stereo connection:

In the diagram, speaker connections are indicated in the form of resistors RL. The amplifier operates normally at 4 volts. The following figure shows a bridged circuit that uses one speaker, but produces more power than the stereo version:

The following figure shows the amplifier circuits on, both circuits are taken from the datasheet. Power supply 18 volts, power 14 watts:

The acoustics connected to the amplifier can have different impedances, most often it is 4-8 Ohms, sometimes there are speakers with a resistance of 16 Ohms. You can find out the resistance of the speaker by turning it over with its back side facing you; the rated power and resistance of the speaker are usually written there. In our case it is 8 ohms, 15 watts.

If the speaker is inside the column and there is no way to see what is written on it, then the speaker can be ringed with a tester in ohmmeter mode by selecting a measurement limit of 200 Ohms.

Speakers have polarity. The cables that connect the speakers are usually marked in red, for the wire that is connected to the positive of the speaker.

If the wires are not marked, you can check the correct connection by connecting the battery plus with plus, minus with minus of the speaker (conditionally), if the speaker cone moves out, then we guessed the polarity. More different ULF circuits, including tube ones, can be found in. It contains, we think, the largest selection of schemes on the Internet.