Car radio amplifiers have fairly modest power parameters. Even if they indicate 4x50 W, in reality it usually does not exceed 20 W per channel. Modern speaker systems have a power of at least 50 W, so without the use of special amplifiers they are not able to reveal their full potential.
| (3) | (7) | (1) | (2) |
| (2) | (2) | (2) | (2) |
| (1) | (2) |
Modern 2 channel amplifiers Designed to connect to two speakers or one subwoofer. A bridge circuit is used for this. Thanks to quality amplifier You can increase the music volume and the threshold for distortion. They may appear when the speakers are played at high volumes. Branded amplifiers will deepen the bass and increase the detail of the sound. Their presence is prerequisite for connecting a subwoofer.
Advantages of two-channel amplifiers
Don't think that 2 channel amplifiers inferior to their four-channel and multi-channel counterparts in everything. For example, they are highly flexible and easy to build sound system. Often, drivers do not need an abundance of channels at all. If you need to improve your sound system in the future, you can additionally buy a 2-channel amplifier. Of course, the cost of two devices will be higher than one with four channels. However, it will be possible to separately configure the rear and front speakers. In four-channel devices this feature is simply not available.
Amplifiers for two channels have their own weak sides. Thus, when a subwoofer is connected to them, the resulting power will be inferior to the parameters obtained when using four-channel devices.
What to look for when choosing a 2-channel amplifier
One important parameter is the size and weight of the device - it must be able to fit on an AV rack. If the device is too large, additional space will be required for it. It is also important that appearance The amplifier was combined with the interior design.
An important parameter is the type of amplifier. Today there are such devices:
- Transistor- their elemental base is built on field-effect or bipolar transistors. The devices allow you to obtain high power, crisp and energetic sound in comparison with tube analogues.
- Tube- electronic vacuum tubes are used to build device cascades. Thanks to this, you can get a special sound. Such devices are in demand among fans of Hi-Fi equipment.
- Digital - The devices are based on integrated circuits. The devices operate according to digital principle gain. They are highly efficient and compact in size.
- Hybrid- These may include vacuum tubes, semiconductor components, as well as integrated circuits.
An important parameter when choosing is the power of the device and the dumping factor. The first parameter reports the number of watts that are supplied to each channel, the second is a dimensionless coefficient. The volume level that can be obtained depends on these indicators.
Sound purity depends on the signal-to-noise ratio and nonlinear distortion factor. The first parameter should be as large as possible, but not lower than 100 dB. But the nonlinear distortion coefficient should be minimal.
Another important parameter is price 2 channel amplifiers. If a device is too cheap, it makes you think about its quality. Therefore, it is better to opt for devices in the middle or high price range.
Choosing the right amplifier for your car will help you get loud and powerful sound, which will give you additional pleasure from your trip!
Brand Lanzar is the embodiment of reliability, technology and power. Lovers of excellent sound need to pay close attention to the products of the American company. Over more than two decades of its activity, the brand has developed many models of subwoofers and amplifiers that delight car owners around the world.
American Lanzar company began its activities in the mid-1990s in California. In just 20 years, it was able to grow from a simple garage production into one of the most reputable and recognized manufacturers of car amplifiers in the world. The brand's engineers developed optical isolation technology and invented neodymium magnets.
Brand Lanzar was one of the first to reduce the level of sound distortion using 30 volt technology. During its history, the company was able to set several world records. At the same time, the cost of its products is at a level acceptable to the consumer. Trademark Lanzar offers its customers a wide selection of audio equipment.
It wasn't until 1996 that Lanzar audio products were able to break six USAC world records and reach the IASCA finals. Active innovation has helped the company develop many technologies that are now used in products from other manufacturers.
Modern audio equipment Lanzar
Today the lineup Lanzar company has dozens of advanced products. The most prominent representatives are:
- subwoofers and amplifiers ORTIDRIVE, the power of which does not exceed 6 kW;
- midrange speakers;
- capacitors;
- split systems;
- reliable OPTISCION subwoofers and amplifiers;
- tweeters;
- processing processors;
- Heritage 2 and 4 channel amplifiers;
- component and coaxial speaker systems.
To your clients Lanzar brand offers about fifty models of amplifiers and subwoofers, as well as 70 different speaker systems. Therefore, it will not be difficult to choose exactly the equipment that will be an excellent addition to your car and will satisfy your music needs.
Lanzar products offered at an attractive price. Each product is highly reliable and powerful. By choosing them, you will never be disappointed!
Photo sent by Alexander (Allroy), Novorossiysk
By chance, I received a “modernized” power amplifier “Oda-UM102S”. The modernization was carried out by an unknown master so severely that only good “meaty” radiators remained alive. So I decided to adapt my new project to them, which smoothly flowed out of the desire to try out a new idea in hardware.
Historical reference
The Oda 102 Stereo stereo radio complex has been produced by the Murom RIP plant since 1986. The complex provided reception of mono and stereo broadcasts in the VHF range, recording of mono and stereo programs, with subsequent playback. The complex consisted of 5 functionally complete blocks: VHF tuner “Oda-102S”, cassette recorder-attachment “Oda-302S”, power amplifier “Oda UM-102S”, preamp"Oda UP-102S" and 2 acoustic systems "15AS-213".
Fragment excluded. Our magazine exists on donations from readers. The full version of this article is available only
How to make L1 I, but if this option bothers anyone, then the coil can be wound on a 2-watt 10-33 Ohm resistor with a wire with a diameter of 0.8 mm in one layer.
VT5, VT6 are equipped with small radiators, which are an aluminum plate 10x20 mm.
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Thank you for your attention!
Igor Kotov, editor-in-chief of Datagor magazine
Thank you for your attention!
Andrey Zelenin,
Kyrgyzstan, Bishkek
Another summer project. This time I wanted to create a super powerful amplifier complex for a car. I had a few hundred dollars at my disposal, so I could buy new components rather than rummaging through the trash for every resistor like I did last time.
So, the new amplifier had to operate from 12 Volts, I decided to assemble a complex of Hi-Fi amplifiers. The first to be completed was the Laznar subwoofer amplifier, which we will talk about today.
The lanzar layout is completely linear - from input to output. The maximum power of the circuit according to the application is 390 watts and the circuit can easily develop the specified power. Like any powerful amplifier, Lanzar is also powered from a bipolar source. The upper peak of the supply voltage is ±70 V, the lower ±30 V, although it may be less, but if you are going to power the amplifier from ±30 V, I advise you not to do this, since the Lanzar itself is a powerful and high-quality amplifier and with such power supply the operation of individual circuit nodes.
The limiting resistors of the differential stages are selected based on the nominal supply voltage, the selection of the nominal is given below (the power of the resistors is 1 watt, thanks to det for the plate).
| Power supply ±70 V | 3.3 kOhm…3.9 kOhm |
| Power supply ±60 V | 2.7 kOhm…3.3 kOhm |
| Power supply ±50 V | 2.2 kOhm…2.7 kOhm |
| Power supply ±40 V | 1.5 kOhm…2.2 kOhm |
| Power supply ±30 V | 1.0 kOhm…1.5 kOhm |
Amplifier lanzar printed circuit board.lay
Zener diodes are designed to stabilize the supply voltage of differential cascades. You should use 15 Volt zener diodes with a power of 1-1.3 watts.
It is advisable to use transistors that are used in the circuit, although I had to use analogues.
Coil - wound with a 0.8 mm wire on a drill with a diameter of 10 mm. The coil turns are glued together with superglue for reliability.
The emitter resistors of the output transistors are selected with a power of 5 watts; during operation they can overheat. The value of these resistors can be selected in the region of 0.22-0.30 Ohms.
3.9 Ohm resistors are selected with a power of 2 watts.
The amplifier operates in class AB, therefore, to cool the transistors of the output stage, a serious heat sink is needed; in my case, a radiator from the domestic radio engineering amplifier U-101 was used.
It is better to take a multi-turn tuning resistor 1 kOhm; it is used to adjust the quiescent current of the output stage; a multi-turn resistor allows you to make very precise adjustments.
All output stage transistors are secured to the heat sink through insulating plates and washers. Before starting, carefully check for short circuits of the transistor terminals to the heat sink.
An input capacitor with a capacity of 1 μF can be selected to suit your taste, but since lanzar is mostly used to power the subwoofer channel, it is advisable to take a larger capacitor capacity.
All film capacitors are 63 volts or more; there should be no problems with them, since almost all film capacitors are made for the specified voltage. Capacitors can be replaced with ceramic ones, but this may affect the sound quality of the amplifier.
The power table and main parameters of the amplifier are presented below.
| PARAMETER | PER LOAD | ||
| 8 ohm | 4 Ohm | 2 Ohm (4 ohm bridge) |
|
| Maximum supply voltage, ± V | 65 | 60 | 40 |
| Maximum output power, W at distortion up to 1% and supply voltage: | |||
| ±30 V | 40 | 85 | 170 |
| ±35 V | 60 | 120 | 240 |
| ±40 V | 80 | 160 | 320 |
| ±45 V | 105 | 210 | DO NOT TURN ON!!! |
| ±50 V | 135 | 270 | DO NOT TURN ON!!! |
| ±55 V | 160 | 320 | DO NOT TURN ON!!! |
| ±60 V | 200 | 390 | DO NOT TURN ON!!! |
| ±65 V | 240 | DO NOT TURN ON!!! | DO NOT TURN ON!!! |
| Gain coefficient, dB | 24 | ||
| Non-linear distortion at 2/3 of maximum power, % | 0,04 | ||
| Output signal slew rate, not less than V/µS | 50 | ||
| Input impedance, kOhm | 22 | ||
| Signal-to-noise ratio, not less, dB | 90 | ||
It is not recommended to increase the supply voltage rating more than ±60 V, but since I am a fan of force majeure situations, I applied ±75 Volt to the circuit, removing about 400 watts, although everything on the board began to heat up, I don’t think it’s worth repeating my experience, perhaps I was just lucky (I replaced the diff cascade resistors with 4kOhm ones).
Below is a list of components for assembling a Lanzar amplifier with your own hands.
- C3,C2 = 2 x 22µ0
- C4 = 1 x 470p
- C6,C7 = 2 x 470µ0 x 25V
- C5,C8 = 2 x 0µ33C11,C9 = 2 x 47µ0
- C12,C13,C18 = 3 x 47p
- C15,C17,C1,C10 = 4 x 1µ0
- C21 = 1 x 0µ15
- C19,C20 = 2 x 470µ0 x 100V
- C14,C16 = 2 x 220µ0 x 100V
- L1 = 1 x
- R1 = 1 x 27k
- R2,R16 = 2 x 100
- R8,R11,R9,R12 = 4 x 33
- R7,R10 = 2 x 820
- R5,R6 = 2 x 6k8
- R3,R4 = 2 x 2k2
- R14,R17 = 2 x 10
- R15 = 1 x 3k3
- R26,R23 = 2 x 0R33
- R25 = 1 x 10k
- R28,R29 = 2 x 3R9
- R27,R24 = 2 x 0.33
- R18 = 1 x 47
- R19,R20,R22
- R21 = 4 x 2R2
- R13 = 1 x 470
- VD1,VD2 = 2 x 15V
- VD3,VD4 = 2 x 1N4007
- VT2,VT4 = 2 x 2N5401
- VT3,VT1 = 2 x 2N5551
- VT5 = 1 x KSE350
- VT6 = 1 x KSE340
- VT7 = 1 x BD135
- VT8 = 1 x 2SC5171
- VT9 = 1 x 2SA1930
- VT10,VT12 = 2 x 2SC5200
- VT11,VT13 = 2 x 2SA1943
- X1 = 1 x 3k3
First startup and setup
The first start-up of the amplifier should be done with the INPUT SHORTED TO GROUND, this is less likely to burn something if the amplifier is assembled incorrectly or there is a problem with the operation of the components. CHECK THE INSTALLATION CAREFULLY before starting. Observe the polarity of the power supply, pinout of transistors and correct connection Zener diodes, if switched on incorrectly, the latter work as a semiconductor diode.
power unit- to begin with, you can use a low-power power supply of 1000 watts. It is advisable to supply power in the region of bipolar 40 Volts. When using network transformers, it is recommended to use a capacitor bank with a capacity of 15,000 µF per arm, or better yet, up to 30,000 µF. When using switching power supplies, 5000uF will be sufficient.
In my case, the amplifier must be powered by a pulse voltage converter, so I used a block of 5 capacitors with a capacity of 1000 μF (each), i.e. There is a working capacitance of 5000 μF in the shoulder.
When using a mains transformer, the secondary winding is connected to the mains through a series-connected incandescent lamp; this is also an additional precaution.
We start the amplifier, if there are no explosions or smoke effects, then we leave the amplifier on for 10-15 seconds, then turn it off and check the heat dissipation on the output stage transistors by touch; if no heat is felt, then everything is OK. Next, disconnect the output wire from the ground and turn on the amplifier (we connect acoustics to the amplifier output in advance). We touch the input of the amplifier with our finger, the acoustics should roar, if everything is so, then the amplifier is working.
Next, you can attach a heat sink to the outputs and turn on the amplifier while listening to music. In general, amplifiers of this type require a preamplifier when applying low-power signals to the input (for example, from a PC, player or mobile phone) the amplifier will not sound particularly loud, since the input signal rating is clearly not enough for maximum power. During the experiments, a signal was given from music center, and I advise you too.
Turn on the amplifier for 10-20 minutes at medium volume and adjust the quiescent current of the amplifier. It is advisable to set the TP in the region of 100-130mA. Setting the quiescent current and measuring the power of the amplifier are shown in the diagrams.
REVIEW OF LANZAR POWER AMPLIFIER
Frankly speaking, I was very surprised that the expression SOUND AMPLIFIER was gaining so much popularity. As far as my worldview allows me, only one object can act under the sound amplifier - a horn. It has really been amplifying sound for decades now. Moreover, the horn can amplify sound in both directions.
As can be seen from the photo, the horn has nothing in common with electronics, however search queries POWER AMPLIFIER is increasingly being replaced by SOUND AMPLIFIER, but the full name of this device, AUDIO FREQUENCY POWER AMPLIFIER, is entered only 29 times a month versus 67,000 requests for SOUND AMPLIFIER.
I’m just curious what this is connected with... But that was a prologue, and now the fairy tale itself:
Schematic diagram The LANZAR power amplifier is shown in Figure 1. This is an almost standard symmetrical circuit, which has made it possible to seriously reduce nonlinear distortions to a very low level.
This circuit has been known for quite a long time; back in the eighties, Bolotnikov and Ataev presented a similar circuit on a domestic element base in the book “Practical circuits for high-quality sound reproduction.” However, work with this circuitry did not begin with this amplifier.
It all started with the PPI 4240 car amplifier circuit, which was successfully repeated:
Schematic diagram car amplifier PPI 4240
Next was the article “Opening Amplifier -2” from Iron Shikhman (the article has unfortunately been removed from the author’s website). It dealt with the circuitry of the Lanzar RK1200C car amplifier, where the same symmetrical circuitry was used as an amplifier.
It is clear that it is better to see once than to hear a hundred times, so delving into my hundred-year-old recorded discs, I found the original article and present it as a quote:
OPENING THE AMPLIFIER - 2
A.I. Shikhatov 2002
A new approach to the design of amplifiers involves the creation of a line of devices using similar circuit solutions, common components and style. This allows, on the one hand, to reduce design and manufacturing costs, and on the other hand, it expands the choice of equipment when creating an audio system.
New line Lanzar amplifiers The RACK series is designed in the spirit of rack-mounted studio equipment. The front panel, measuring 12.2 x 2.3 inches (310 x 60 mm), contains controls, and the rear panel contains all connectors. This arrangement not only improves the appearance of the system, but also simplifies the work - cables do not get in the way. On the front panel you can mount the included mounting strips and carrying handles, then the device takes on a studio look. The ring illumination of the sensitivity control only enhances the similarity.
The radiators are located on the side surface of the amplifier, which allows you to stack several devices in a rack without interfering with their cooling. This is an undoubted convenience when creating extensive audio systems. However, when installing in a closed rack, you need to worry about air circulation - install supply and exhaust fans, temperature sensors. In short, professional equipment requires a professional approach in everything.
The line includes six two-channel and two four-channel amplifiers, differing only in output power and cabinet length.
The block diagram of the crossover of the Lanzar RK series amplifiers is shown in Figure 1. A detailed diagram is not given, since there is nothing original in it, and it is not this unit that determines the main characteristics of the amplifier. The same or similar structure is used in most modern midrange amplifiers. price category. The range of functions and characteristics are optimized taking into account many factors:
On the one hand, the crossover capabilities should allow the construction of standard audio system options (front plus subwoofer) without additional components. On the other hand, there is little point in introducing a full set of functions into a built-in crossover: This will significantly increase the cost, but in many cases it will remain unclaimed. It is more convenient to delegate complex tasks to external crossovers and equalizers, and to disable the built-in ones.
The design uses dual KIA4558S operational amplifiers. These are low-noise, low-distortion amplifiers designed with "audio" applications in mind. As a result, they are widely used in preamp stages and crossovers.
The first stage is a linear amplifier with variable gain. It matches the output voltage of the signal source with the sensitivity of the power amplifier, since the gain of all other stages is equal to unity.
The next stage is the bass boost control. In amplifiers of this series, it allows you to increase the signal level at a frequency of 50 Hz by 18 dB. In products from other companies, the rise is usually less (6-12 dB), and the tuning frequency can be in the region of 35-60 Hz. By the way, such a regulator requires a good power reserve of the amplifier: an increase in gain by 3 dB corresponds to doubling the power, by 6 dB - quadrupling, and so on.
This is reminiscent of the legend about the inventor of chess, who asked the Raja for one grain for the first square of the board, and for each subsequent one - twice as many grains as for the previous one. The frivolous Raja could not fulfill his promise: there were no such quantity of grains on the entire Earth... We are in a more advantageous position: an increase in the level by 18 dB will increase the signal power “only” 64 times. In our case, 300 W are available, but not every amplifier can boast such a reserve.
The signal can then be fed directly to a power amplifier, or the required frequency band can be selected using filters. The crossover part consists of two independent filters. The low-pass filter is tunable in the range of 40-120 Hz and is designed to work exclusively with a subwoofer. The tuning range of the high-pass filter is noticeably wider: from 150 Hz to 1.5 kHz. In this form, it can be used to work with a broadband front or for the MF-HF band in a system with channel amplification. The tuning limits, by the way, were chosen for a reason: in the range from 120 to 150 Hz there is a “hole” in which the acoustic resonance of the cabin can be hidden. It is also noteworthy that the bass booster is not turned off in any of the modes. Using this cascade simultaneously with a high-pass filter allows you to adjust the frequency response in the interior resonance region no worse than using an equalizer.
The last cascade has a secret. Its task is to invert the signal in one of the channels. This will allow you to use the amplifier in a bridge connection without additional devices.
Structurally, the crossover is made on a separate printed circuit board, which is connected to the amplifier board using a connector. This solution allows the entire line of amplifiers to use only two crossover options: two-channel and four-channel. The latter, by the way, is simply a “double” version of the two-channel one and its sections are completely independent. The main difference is the changed layout of the printed circuit board.
Amplifier
The Lanzar power amplifier is made according to a typical scheme for modern designs, shown in Figure 2. With minor variations, it can be found in most amplifiers of the middle and lower price category. The only difference is in the types of parts used, the number of output transistors and supply voltage. The diagram of the right channel of the amplifier is shown. The left channel circuit is exactly the same, only the part numbers start with a one instead of a two.
A filter R242-R243-C241 is installed at the amplifier input, eliminating radio frequency interference from the power supply. Capacitor C240 does not allow the DC component of the signal to enter the power amplifier input. These circuits do not affect the frequency response of the amplifier in the audio frequency range.
To avoid clicks when turning on and off, the amplifier input is connected to a common wire with a transistor switch (this unit is discussed below, together with the power supply). Resistor R11A eliminates the possibility of self-excitation of the amplifier when the input is closed.
The amplifier circuit is completely symmetrical from input to output. A double differential stage (Q201-Q204) at the input and a stage on transistors Q205, Q206 provide voltage amplification, the remaining stages provide current amplification. The cascade on transistor Q207 stabilizes the quiescent current of the amplifier. To eliminate its “asymmetry” on high frequencies, it is bypassed by a mylar capacitor C253.
The driver stage on transistors Q208, Q209, as befits a preliminary stage, operates in class A. A “floating” load is connected to its output - resistor R263, from which the signal is removed to excite the transistors of the output stage.
The output stage uses two pairs of transistors, which made it possible to extract 300 W of rated power and up to 600 W of peak power. Resistors in the base and emitter circuits eliminate the consequences of technological variation in the characteristics of transistors. In addition, resistors in the emitter circuit serve as current sensors for the overload protection system. It is made on transistor Q230 and controls the current of each of the four transistors in the output stage. When the current through an individual transistor increases to 6 A or the current of the entire output stage to 20 A, the transistor opens, issuing a command to the blocking circuit of the supply voltage converter.
The gain is set by the negative circuit feedback R280-R258-C250 and is equal to 16. Correction capacitors C251, C252, C280 ensure the stability of the amplifier covered by OOS. The circuit R249, C249 connected at the output compensates for the increase in load impedance at ultrasonic frequencies and also prevents self-excitation. In the audio circuits of the amplifier, only two electrolytic non-polar capacitors are used: C240 at the input and C250 in the OOS circuit. Due to their large capacity, it is extremely difficult to replace them with other types of capacitors.
Power supply The high-power power supply is made of field-effect transistors. A special feature of the power supply is the separate output stages of the converter for powering the power amplifiers of the left and right channels. This structure is typical for high-power amplifiers and makes it possible to reduce transient interference between channels. For each converter there is a separate LC filter in the power supply circuit (Figure 3). Diodes D501, D501A protect the amplifier from erroneous switching on in the wrong polarity.
Each converter uses three pairs of field-effect transistors and a transformer wound on a ferrite ring. The output voltage of the converters is rectified by diode assemblies D511, D512, D514, D515 and smoothed by filter capacitors with a capacity of 3300 μF. The output voltage of the converter is not stabilized, so the amplifier power depends on the voltage on-board network. From the negative voltage of the right and positive voltage of the left channel, parametric stabilizers generate voltages of +15 and -15 volts to power the crossover and differential stages of power amplifiers.
The master oscillator uses the KIA494 (TL494) microcircuit. Transistors Q503, Q504 increase the output of the microcircuit and speed up the closing of the key transistors of the output stage. The supply voltage is supplied to the master oscillator constantly, the switching is controlled directly from the Remote circuit of the signal source. This solution simplifies the design, but when turned off, the amplifier consumes insignificant quiescent current (several milliamps).
The protection device is made on a KIA358S chip containing two comparators. The supply voltage is supplied to it directly from the Remote circuit of the signal source. Resistors R518-R519-R520 and a temperature sensor form a bridge, the signal from which is fed to one of the comparators. A signal from the overload sensor is supplied to another comparator through a driver on transistor Q501.
When the amplifier overheats, a high level voltage, the same level appears at pin 8 when the amplifier is overloaded. In any emergency case, signals from the output of the comparators through the OR diode circuit (D505, D506, R603) block the operation of the master oscillator at pin 16. Operation is restored after eliminating the causes of the overload or cooling the amplifier below the temperature sensor response threshold.
The overload indicator is designed in an original way: the LED is connected between the +15 V voltage source and the on-board network voltage. During normal operation, voltage is applied to the LED in reverse polarity and it does not light. When the converter is blocked, the +15 V voltage disappears, the overload indicator LED turns on between the on-board voltage source and the common wire in the forward direction and begins to glow.
Transistors Q504, Q93, Q94 are used to block the input of the power amplifier during transient processes when turning on and off. When the amplifier is turned on, capacitor C514 is slowly charged, transistor Q504 is in the open state at this time. The signal from the collector of this transistor opens the keys Q94,Q95. After charging the capacitor, transistor Q504 closes, and the -15 V voltage from the output of the power supply reliably blocks the keys. When the amplifier is turned off, transistor Q504 instantly opens through diode D509, the capacitor quickly discharges and the process repeats reverse order.
Design
The amplifier is mounted on two printed circuit boards. On one of them there is an amplifier and a voltage converter, on the other there are crossover elements and turn-on and overload indicators (not shown in the diagrams). The boards are made of high-quality fiberglass with a protective coating for the tracks and are mounted in a housing made of an aluminum U-shaped profile. Powerful transistors The amplifier and power supply are pressed with pads to the side shelves of the case. Profiled radiators are attached to the outside of the sides. Front and back panels The amplifiers are made of anodized aluminum profile. The entire structure is secured with self-tapping screws with hexagon heads. That's all, actually - the rest can be seen in the photographs.
As you can see from the article, the original LANZAR amplifier itself is not bad at all, but I wanted it to be better...
I searched the forums, of course, Vegalab, but didn’t find much support - only one person responded. Perhaps it’s for the better - there aren’t a ton of co-authors. Well, in general, this particular appeal can be considered Lanzar’s birthday - at the time of writing the comment, the board was already etched and soldered almost completely.
So Lanzar is already ten years old...
After several months of experiments, the first version of this amplifier, called "LANZAR", was born, although of course it would be fairer to call it "PIPIAY" - it all started with him. However, the word LANZAR sounds much more pleasant to the ear.
If someone SUDDENLY considers the name an attempt to play on a brand name, then I dare to assure him that there was nothing like that in mind and the amplifier could have received absolutely any name. However, it became LANAZR in honor of the LANZAR company, since this particular automotive equipment is included in that small list of those who are personally respected by the team that worked on fine-tuning this amplifier.
A wide range of supply voltages makes it possible to build an amplifier with a power from 50 to 350 W, and at powers up to 300 W for UMZCH coffee. nonlinear distortion does not exceed 0.08% throughout the entire audio range, which allows the amplifier to be classified as Hi-Fi.
The figure shows the appearance of the amplifier.
The amplifier circuit is completely symmetrical from input to output. A double differential stage (VT1-VT4) at the input and a stage on transistors VT5, VT6 provide voltage amplification, the remaining stages provide current amplification. The cascade on transistor VT7 stabilizes the quiescent current of the amplifier. To eliminate its “asymmetry” at high frequencies, it is bypassed with capacitor C12.
The driver stage on transistors VT8, VT9, as befits a preliminary stage, operates in class A. A “floating” load is connected to its output - resistor R21, from which the signal is removed to excite the transistors of the output stage. The output stage uses two pairs of transistors, which made it possible to extract up to 300 W of rated power from it. Resistors in the base and emitter circuits eliminate the consequences of technological variation in the characteristics of transistors, which made it possible to abandon the selection of transistors by parameters.
We remind you that when using transistors from the same batch, the spread in parameters between transistors does not exceed 2% - this is the manufacturer’s data. In reality, it is extremely rare that parameters go beyond the three percent zone. The amplifier uses only “one-party” terminal transistors, which, together with balance resistors, made it possible to maximally align the operating modes of the transistors with each other. However, if the amplifier is being made for a loved one, then it will not be useless to assemble the test stand given at the end of THIS ARTICLE.
Regarding the circuitry, it only remains to add that such a circuitry solution provides one more advantage - complete symmetry eliminates transient processes in the final stage (!), i.e. at the moment of switching on, there are no surges at the output of the amplifier, which are characteristic of most discrete amplifiers.
Figure 1 - schematic diagram of the LANZAR amplifier. INCREASE .
Figure 2 - appearance of the LANZAR V1 amplifier.
Figure 3 - appearance of the LANZAR MINI amplifier
Schematic diagram of a powerful stage power amplifier 200 W 300 W 400 W UMZCH on high quality transistors Hi-Fi UMZCH
Power amplifier specifications:
390
As can be seen from the characteristics, the Lanzar amplifier is very versatile and can be successfully used in any power amplifiers that require good characteristics UMZCH and high output power.
You can, of course, praise this amplifier for quite a long time, but it is somehow not modest to engage in self-praise. Therefore, we decided to look at the reviews of those who heard how it works. I didn’t have to search for long - this amplifier has been discussed on the Soldering Iron forum for a long time, so take a look for yourself: There were, of course, negative ones, but the first was from an incorrectly assembled amplifier, the second from an unfinished version with a domestic configuration... Amplifier audio frequency UM LANZAR based on powerful bipolar transistors will allow you to assemble a very high-quality audio amplifier in a short period of time. Power supply ±70 V - 3.3 kOhm...3.9 kOhm Of course, ALL resistors are 1 W, zener diodes at 15V are preferably 1.3 W Regarding heating VT5, V6 - in this case you can increase the radiators on them or increase their emitter resistors from 10 to 20 Ohms. About LANZAR amplifier power filter capacitors: |
Since this amplifier is quite popular and questions about it quite often come self-production The following articles were written:
Transistor amplifiers. Basics of circuit design
Transistor amplifiers. Building a balanced amplifier
Lanzar tuning and circuit design changes
Setting up the LANZAR power amplifier
Increasing the reliability of power amplifiers using the example of the LANZAR amplifier
The penultimate article quite intensively uses the results of parameter measurements using the MICROCAP-8 simulator. How to use this program is described in detail in a trilogy of articles:
AMPovichok. CHILDREN'S
AMPovichok. YOUTHFUL
AMPovichok. ADULT
BUY TRANSISTORS FOR LANZAR AMPLIFIER |
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And finally, I would like to give the impressions of one of the fans of this circuit, who assembled this amplifier on his own:
The amplifier sounds very good, the high damping factor represents a completely different level of bass reproduction, and high speed The signal build-up does an excellent job of reproducing even the smallest sounds in the high-frequency and mid-range.
You can talk a lot about the delights of the sound, but the main advantage of this amplifier is that it does not add any color to the sound - it is neutral in this regard, and only repeats and amplifies the signal from the sound source.
Many who heard the sound of this amplifier (assembled according to this circuit) gave the highest rating to its sound, as a home amplifier for high-quality speakers, and its endurance in *close to military action* conditions gives the chance to use it professionally for scoring various events at outdoors, as well as in the halls.
For a simple comparison, I will give an example that will be most relevant among radio amateurs, as well as among those already *sophisticated good sound*
in the soundtrack of Gregorian-Moment of Peace, the choir of monks sounds so realistic that the sound seems to pass right through, and the female vocals sound as if the singer is standing right in front of the listener.
When using time-tested speakers such as 35ac012 and others like them, the speakers get a new lease of life and sound just as clearly even at maximum volume.
For example, for fans of loud music, when listening to the music track Korn ft. Skrillex - Get Up
The speakers were able to play all the difficult moments with confidence and without noticeable distortion.
As a contrast to this amplifier, we took an amplifier based on the TDA7294, which, already at a power of less than 70 W per 1 channel, was able to overload the 35ac012 so that it was clearly audible how the woofer coil hit the core, which was fraught with damage to the speaker and, as a result, losses.
The same cannot be said about the *LANZAR* amplifier - even with about 150W of power supplied to these speakers, the speakers continued to work perfectly, and the woofer was so well controlled that no extraneous sounds it just wasn't there.
In the musical composition Evanescence - What You Want
The scene is so elaborate that you can even hear the drumsticks hitting each other. And in the composition Evanescence - Lithium Official Music Video
The skipping part is replaced by an electric guitar, so that the hair on your head just begins to move, because there is simply no *longness* to the sound, and the quick transitions are perceived as if a painful form of 1 is flashing in front of you, one moment and YOU are immersed in new world. Not forgetting about the vocals, which throughout the entire composition bring generalization to these transitions, giving harmony.
In the composition Nightwish - Nemo
The drums sound like gunshots, clearly and without boom, and the rumble of thunder at the beginning of the composition simply makes you look around.
In the composition Armin van Buuren ft. Sharon den Adel - In and Out of Love
We are again immersed in the world of sounds that penetrate us through and through, giving us a feeling of presence (and this is without any equalizers or additional stereo expansions)
In the song Johnny Cash Hurt
We are again immersed in the world of harmonious sound, and the vocals and guitar sound so clearly that even the increasing tempo of the performance is perceived as if we are sitting behind the wheel of a powerful car and pressing the gas pedal to the floor, while not letting go but pressing harder and harder.
With a good source of sound signal and good acoustics, the amplifier *doesn't bother you* at all, even at the highest volume.
Once a friend was visiting me and he wanted to listen to what this amplifier was capable of, putting on a track in AAC format Eagles - Hotel California, he turned it up to full volume, while instruments began to fall from the table, his chest felt like well-placed punches of a boxer , the glass tinkled in the wall, and we were quite comfortable listening to music, while the room was 14.5 m2 with a ceiling of 2.4 m.
We installed ed_solo-age_of_dub, the glass in two doors cracked, the sound was felt by the whole body, but the head did not hurt.
The board on the basis of which video was made in LAY-5 format.
If you assemble two LANZAR amplifiers, can they be bridged?
You can, of course, but first, a little poetry:
For a typical amplifier, the output power depends on the supply voltage and load resistance. Since we know the load resistance and we already have power supplies, it remains to be seen how many pairs of output transistors to use.
Theoretically, the total output power of alternating voltage is the sum of the power delivered output stage, which consists of two transistors - one n-p-n, the second p-n-p, therefore each transistor is loaded with half the total power. For the sweet couple 2SA1943 and 2SC5200, the thermal power is 150 W, therefore, based on the above conclusion, 300 W can be removed from one pair of outputs.
But practice shows that in this mode the crystal simply does not have time to transfer heat to the radiator and thermal breakdown is guaranteed, because the transistors must be insulated, and the insulating spacers, no matter how thin they are, still increase the thermal resistance, and the surface of the radiator is unlikely to who polishes to micron precision...
So for normal operation, for normal reliability, quite a lot of people have adopted slightly different formulas for calculating the required number of output transistors - the output power of the amplifier should not exceed the thermal power of one transistor, and not the total power of the pair. In other words, if each transistor of the output stage can dissipate 150 W, then the output power of the amplifier should not exceed 150 W, if there are two pairs of output transistors, then the output power should not exceed 300 W, if three - 450, if four - 600.
Well, now the question is - if typical amplifier can produce 300W and we turn on two such amplifiers in a bridge, then what will happen?
That's right, the output power will increase approximately twofold, but the thermal power dissipated by the transistors will increase by 4 times...
So it turns out that to build a bridge circuit you will no longer need 2 pairs of outputs, but 4 on each half of the bridge amplifier.
And then we ask ourselves the question - is it necessary to drive 8 pairs of expensive transistors to get 600 W, if you can get by with four pairs simply by increasing the supply voltage?
Well, of course, it’s the owner’s business....
Well, several options of PRINTED BOARDS for this amplifier will not be superfluous. There are also original versions, and some taken from the Internet, so it’s better to double-check the board - it will give you mental training and fewer problems when adjusting the assembled version. Some options have been corrected, so there may not be any errors, or maybe something has slipped through the cracks...
One more question remains unanswered - assembly of the LANZAR amplifier using domestic components.
Of course, I understand that crab sticks are made not from crabs, but from fish. So is Lanzar. The fact is that in all attempts to assemble on domestic transistors, the most popular ones are used - KT815, KT814, KT816, KT817, KT818, KT819. These transistors have a lower gain and a unity gain frequency, so you won’t hear Lanzarov’s sound. But there is always an alternative. At one time, Bolotnikov and Ataev proposed something similar in circuit design, which also sounded pretty good:
You can see more details about how much power a power supply is needed for a power amplifier in the video below. The STONECOLD amplifier is taken as an example, but this measurement makes it clear that the power of the network transformer may be less than the power of the amplifier by about 30%.
At the end of the article I would like to note that this amplifier A BIPOLAR power supply is required, since the output voltage is formed from the positive and negative power supply arms. The diagram of such a power supply is shown below:
You can draw conclusions about the overall power of the transformer by watching the video above, but I’ll give a short explanation about the other details.
The secondary winding must be wound with a wire whose cross-section is designed for the overall power of the transformer plus an adjustment for the shape of the core.
For example, we have two channels of 150 W each, therefore the overall power of the transformer must be at least 2/3 of the power of the amplifier, i.e. with an amplifier power of 300 W, the transformer power must be at least 200 W. With a power supply of ±40 V into a 4 Ohm load, the amplifier develops about 160 W per channel, therefore the current flowing through the wire is 200 W / 40 V = 5 A.
If the transformer has an W-shaped core, then the voltage in the wire should not exceed 2.5 A per square mm of cross-section - this way there is less heating of the wire, and the voltage drop is less. If the core is toroidal, then the voltage can be increased to 3...3.5 A per 1 square mm of wire cross-section.
Based on the above, for our example, the secondary must be wound with two wires and the beginning of one winding is connected to the ends of the second winding (the connection point is marked in red). The diameter of the wire is D = 2 x √S/π.
At a voltage of 2.5 A we get a diameter of 1.6 mm, at a voltage of 3.5 A we get a diameter of 1.3 mm.
Diode bridge VD1-VD4 not only must calmly withstand the resulting current of 5 A, it must withstand the current that occurs at the moment of switching on, when it is necessary to charge the power filter capacitors C3 and C4, and the higher the voltage, the greater the capacitance, the higher the value of this starting current. Therefore, the diodes must be at least 15 Amperes for our example, and in the case of increasing the supply voltage and using amplifiers with two pairs of transistors in the final stage, 30-40 Ampere diodes or a soft start system are needed.
The capacity of capacitors C3 and C4, based on Soviet circuit design, is 1000 μF for every 50 W of amplifier power. For our example, the total output power is 300 W, which is 6 times 50 W, therefore the capacitance of the power filter capacitors should be 6000 uF per arm. But 6000 is not a typical value, so we round up to the typical value in big side and we get 6800 uF.
Frankly speaking, such capacitors do not come across often, so we put 3 capacitors of 2200 μF in each arm and get 6600 μF, which is quite acceptable. The issue can be solved somewhat simpler - use one 10,000 µF capacitor
Last summer, a car audio complex was created, but a year has passed since then and the time has come for change. First, let me explain the essence of the idea. It was planned to assemble a Hi-Fi amplifier for use in a car. The requirements for the amplifier were as follows: a powerful channel of 250-350 watts to power the subwoofer, two channels to power the rear speakers, and 8 channels to power the low-power front heads, but all the selected amplifiers had to be Hi-Fi. To implement such a large-scale project required finance, nerves and a lot of time, which I had.
Subwoofer amplifier
Rear speaker amplifier
Front speaker amplifier
PRINTED CIRCUIT BOARD
I didn’t think about the board for a long time, all the boards of the individual blocks were available, all I had to do was transfer all the templates to foil fiberglass and etch them. PCB and schematic files are located here. The templates were applied to the common board after some calculations. For this process, I used the well-known LUT method, ironing each template for 90 seconds; ironing must be done carefully so that the toner sticks tightly to the foil surface of the PCB and does not come off when the paper is removed.
Next, let the PCB cool for 5-10 minutes, then carefully remove the paper. First, you need to place the board in a vessel with water and wait a couple of minutes, then carefully remove the paper. I couldn’t find reagents for etching in the town, so I had to go for an alternative. The alternative solution consists of three main components - hydrogen peroxide, citric acid and table salt . In general, my fee cost 12 bottles of hydrogen peroxide (3 percent hydrogen peroxide solution, each bottle 100 mg) - 12 packs of citric acid (pack - 40 mg) purchased at a pharmacy - 9 teaspoons of table salt purchased at a grocery store - stolen from the kitchen of his own home. All components are mixed until the salt and citric acid are completely dissolved.
Due to the large size of the board, difficulties arose with the vessel in which the etching was planned. Here, too, I decided to go for an alternative. I purchased a plastic bag from the store and placed it in a box from some kind of player; the board fit perfectly into such a “vessel”. I poured the solution and put the whole thing in the sun. The entire etching process lasted no more than an hour. Quite a violent reaction, so it needs to be done in clean air. Next you need to erase the toner. To do this, use clean (or not so clean) rags and acetone. The finished board should be washed thoroughly with warm water, then dried with a hairdryer.
Another problem is the disposal of the solution, I acted barbarously by pouring the entire solution into the sewer, when you do the same, make sure that no one sees, otherwise environmentalists will rush in, in my case such a problem did not arise, since I myself am an environmentalist (lol) . Next you need to start drilling holes, and there are very, very many of them. I drilled half of the holes with a 3-kilogram drill, then a mini-drill with all the amenities was purchased at an eBay auction especially for this venture. During the drilling process, I used 0.8mm drills for small components (resistors, capacitors, microcircuits, etc.), 1mm drills for larger ones (amplifier output transistors, power diodes) and 5mm drills for the terminals of the windings of pulse transformers.
The already drilled board needs to be tinned. To do this, you need a soldering iron with a hundred watts, pine rosin, and, of course, tin. I advise you to wear a mask during this process; the smoke from rosin is not toxic, but a whole cloud of smoke is formed here, and it is quite difficult to breathe under such conditions. The glossy tin layer gives the printed circuit board a beautiful appearance and protects the copper traces from oxidation. Only after completing this process do we have a completely finished printed circuit board, and now we can begin installation...
We will start assembling printed circuit board parts for our home amplifier with a power source, or rather two sources, since two power supplies are required. Of course we don't use power transformers on iron, and impulse blocks nutrition.
INVERTER 1
This inverter is designed only to power a subwoofer amplifier using a lanzar circuit. Output voltage +/-65 Volts. The inverter does not have output voltage stabilization, but despite this, I did not observe any serious voltage surges. The inverter was built using a classic push-pull circuit using a PWM controller on a microcircuit TL494. The transformer was wound on two rings of the 3000NM brand (Evgeniy, thank you for helping out and sending the rings from the other side of the world), the dimensions of the rings are 45*28*8. If possible, use ferrite grade 2000NM, it will result in fewer losses in the transformer. I didn’t glue the rings together, I just wrapped them with clear tape. I didn’t round the edges of the ring, I just wrapped the core with a strip of fiberglass in two layers before winding. Fiberglass is not afraid of overheating and provides fairly good winding insulation, although in such industrial-style inverters the windings are never isolated from each other, since the voltage is not so high.
Winding was done with two completely identical busbars, each busbar consisting of 12 wire strands with a diameter of 0.7 mm. Before winding, we take a control wire, we will use it to find out how long the tire is needed. The control wire can be of any type, of any cross-section (for convenience, select a diameter of 0.3-1 mm). So, take the control wire and wind 5 turns around the ring, stretching the turns evenly throughout the ring. Now we unwind the winding, measuring the length, let’s say the length of the wire is 20 cm, therefore, to wind the main winding, the wire must be taken with a margin of 5-7 cm, i.e. 25-27 cm, of course, the length is not exact and is given only as an example. Now let's move on. Since our primary (power) winding consists of two completely similar arms, we need 24 strands of 0.7 mm wire of the same length. Next you need to assemble the tires from 12 cores, twist the ends of the cores and proceed to the winding process.
Different sources provide different winding technologies; this method differs in that it allows you to obtain the most equivalent windings. We wind it with two tires at once; it is advisable to use a harness for convenience, but I wound it without it. We wind 5 turns around the entire ring as carefully as possible, in the end we get 4 bends. To ensure the durability of the turns, we insulate the winding; the test insulation can be anything - tape, electrical tape, thread, etc., as long as the winding holds, if you are sure of the correctness of the winding, then you can install the final insulation (in my case, again fiberglass). Now you need to phase the windings, connecting the beginning of the first half-winding (arm) to the end of the second, or vice versa, the beginning of the second, to the end of the first. At the junction of the windings there is a tap from the middle; power plus 12 Volts is supplied to it according to the circuit. The secondary winding is wound and phased according to the same principle as the primary. The winding consists of 2x24 turns, wound with two tires. Each bus consists of 5 strands of 0.7 mm wire.
The diode rectifier is assembled from 4 series diodes KD213A. These are pulse diodes with a reverse voltage of up to 200 Volts, they feel great at frequencies of 50-80 kHz (although they can operate at frequencies up to 100 kHz), and the maximum permissible current 10 Amps is what you need. The diodes do not require additional cooling, although heat generation may occur during operation.
I used ready-made chokes in the output circuit, from computer power supplies. The chokes are wound on a ferrite rod (length 1.5-2 cm, diameter 6 mm). The winding contains 5-6 turns, wound with 2-2.5 mm wire; for convenience, you can wind it with several strands of thinner wire. I took smoothing electrolytes with a voltage of 100 Volts 1000 μF, they work with a large margin. As a result, there are 4 such capacitors in the shoulder on the inverter board, and two more similar ones are on the board amplifier Lanzar, i.e. the total capacity of the filters in the arm is 5000 µF. Before and after the chokes there are film capacitors with a voltage of 100 Volts; their capacitance is not particularly critical and can be in the region of 0.1-1 µF.
STARTING THE FIRST PSU INVERTER
Before starting the inverter, carefully check the correct installation. Low-power transistors BC556/557 can be replaced with the domestic analogue KT3107, BC546 with KT3102 or any others with similar parameters. Field switches should not heat up during operation without an output load, and with a load the heating of the arms should be uniform. The last stage is heat removal. Field effect transistors in my case, they are reinforced to heat sink from computer unit power supply, through mica spacers and insulating washers.
The circuit implements remote control (REM), i.e. the main, power plus and minus are always connected to the amplifier, and in order for the circuit to start, a plus is applied to the REM point, the BC546 transistor opens and power is supplied to the generator and the inverter’s operating cycle begins. Plus, the remote can be supplied from the car radio, or you can install a small toggle switch in the car that can be used to turn the amplifier on and off.
If you have any problems...
Problem. It happens that the field switches fail the first time they are turned on.
Cause and remedy . The primary winding is incorrectly phased or the transistors are defective. If you are sure of the correct installation and the serviceability of all components, then most likely the primary winding of the transformer is incorrectly phased. To do this, we turn off the secondary circuit, that is, the load that is connected to the secondary winding and start the transformer again (often, problems can arise on the secondary circuits), if everything is the same, then we check the transistors for serviceability, they will most likely be “dead,” replace them and We phase the transformer correctly.
Problem. When turned on, one of the pairs of transistors overheats, the second pair is cold.
Cause and remedy . First, we check the presence of rectangular pulses on pins 9 and 10 of the microcircuit; if everything is ok, then we check the connection of diodes and low-power transistors. This problem arises for two reasons - incorrect connection of low-power driver transistors or unequal arms of the primary winding.
INVERTER 2
Scheme and printed circuit board of the second inverter is completely similar to the first. Output voltage for powering channels OM is 2x55 Volts (+/-55V). The secondary winding this time is wound with 6 strands of 0.8 mm wire and consists of 2x28 turns, wound using the same technology as in the case of the first inverter.
Please ensure that the primary and secondary windings are wound IN THE SAME DIRECTION!
The other secondary is intended to power the amplifier block based on LM1875 microcircuits. The winding consists of 2x8 turns, wound with 4 strands of 0.8 mm wire. After assembling the inverter, we carefully check the installation for errors; if there are none, then take a multimeter and check the secondary circuits for short circuits.
FIRST TURN ON
The first start-up of the inverter should be done from a laboratory power supply with short-circuit protection, and at the time of start-up the protection may erroneously work if the unit is low-power; in my case, a converted power supply with a current of 3.5 A was used. The inverter no-load current is 170-280 mA, depending on the correct calculation of the transformer, the operating frequency of the generator and the type of field switches, the snubber resistor plays a significant role, in my case I had to play with it a little to reduce the consumption of the circuit.
During idling, there should be no heat generation on the keys; if there is any, then there is an installation problem or a non-working component. Before starting, wash the board from fluxes; you can use acetone or solvent for this. And now let’s get down to the UMZCH unit itself...
After successfully starting the power supply, we move on to the most interesting part of the design - the audio power amplifier block. Including filter low frequencies for a subwoofer and a stabilization module.
AMPLIFIER FOR SUBWOOFER ACCORDING TO LANZAR CIRCUIT
Well, what can we say about one of the most repeated power amplifier circuits - the Lanzar circuit was developed back in the 70s of the last century. On a modern high-precision elementary base, Lanzar began to sound even better. In theory, the circuit is excellent for wideband acoustics, distortion at half the volume only 0.04%- full-fledged Hi-Fi.
The output stage of the amplifier is built on a pair 2SA1943 And 2SC5200, all stages are assembled on complementary pairs that are as close as possible in terms of parameters, the amplifier is built entirely on a symmetrical basis. The rated output power of the amplifier is 230-280 watts, but much more can be removed by increasing the input supply voltage. The values of the limiting resistors of the differential stages are selected based on the input voltage. Below is the table.
Power supply ±70 V - 3.3 kOhm...3.9 kOhm
Power supply ±60 V - 2.7 kOhm...3.3 kOhm
Power supply ±50 V - 2.2 kOhm...2.7 kOhm
Power supply ±40 V - 1.5 kOhm...2.2 kOhm
Power supply ±30 V - 1.0 kOhm...1.5 kOhm
These resistors are selected with a power of 1-2 watts; during operation, heat generation may be observed on them.
The regulating transistor was replaced with a domestic one KT815, at that time there was no other one at hand. It is designed to regulate the quiescent current of the output stages; it does not overheat during operation, but is mounted on a common heat sink with the transistors of the output stage.
It is advisable to do the first launch of the circuit from network block power supply, connect a 100-150 watt incandescent lamp in series with the mains winding of the transformer; if there are problems, then burn a minimum of parts. In general, Lanzar’s circuit is not critical to the installation and components; I tried it even with a wide range of components used, using domestic radio components - the circuit shows high parameters even in this case. Lanzar's circuit diagram has two main versions - on bipolar transistors and using field switches in the penultimate stage, in my case first version.
The second pre-output stage operates in a pure class " A", therefore, during operation, the transistors overheat. Transistors of this cascade must be installed on a heat sink, preferably a common one, do not forget about insulation - mica plates and insulating washers for screws.
A correctly assembled circuit starts up without any problems. We do the first launch with INPUT SHORT TO GROUND , i.e. The amplifier input is connected to the middle point from the power supply. If nothing explodes after launch, then you can disconnect the input from the ground. Next we connect the load - the speaker and turn on the amplifier. To make sure the amplifier is working, just touch the bare input wire. If a peculiar roar appears in the head, then the amplifier is working! Then you can strengthen all the power parts with heat sinks and feed them to the amplifier input sound signal. After 15-20 minutes of operation at 30-50% of the maximum volume, you need to adjust the quiescent current. The photo shows everything in detail; it is advisable to use a digital multimeter as a voltage indicator.
Amplifier output power measurement
How to set the quiescent current
LPF AND STABILIZATION UNIT
The low-pass filter and adder are built on two microcircuits. It is designed for smooth adjustment of phase, volume and frequency. The adder is designed to sum the signals of both channels to obtain a more powerful signal. Industrial high-power auto amplifiers use exactly this principle of filtering and summing the signal, but the adder can, if desired, be excluded from the circuit and make do with only a low-pass filter. The filter cuts off all frequencies, leaving only a limit between 35-150 Hz.
Phase adjustment allows you to match the subwoofer with acoustic systems, in some cases it is also excluded. This unit is powered by a stabilized bipolar voltage source +/-15 Volts. Power can be provided using an additional secondary winding, or you can use a bipolar voltage stabilizer to reduce the voltage from the main winding. For this purpose, a bipolar stabilizer has been assembled. Initially, the voltage is reduced by zener diodes, then amplified bipolar transistors and is supplied to linear voltage stabilizers of types 7815 and 7915. At the output of the stabilizer, a stable bipolar power supply is formed, which powers the adder and low-pass filter unit.
Stabilizers and transistors can get hot, but this is quite normal; if desired, they can be mounted on heat sinks, but in my case there is active cooling by a cooler, so heat sinks were not useful, and besides, the heat dissipation is within normal limits, since the low-pass filter unit itself consumes very little.
SLAPPING TO CHIP CIRCUITS
Slap in the face mikruham is not the simplest, but high-quality low-frequency power amplifier. The amplifier is capable of developing a maximum output power of 130 watts and operates over a fairly wide input voltage range. The output stage of the amplifier is built on a pair 2sa1943 2sc5200 and works in mode AB. This version was developed by the author this year, below are its main parameters.
Supply voltage range = +/- 20V... +/- 60V
Nominal supply voltage (100W, 4 Ohm) = +/- 36V
Nominal supply voltage (100W, 8 Ohm) = +/- 48V
Everything is clear with power, but what about distortion?
THD+N (at Pout<=60Вт, 20кГц) <= 0,0009%
THD+N (at maximum output power, 1kHz) = 0.003%
THD+N (at maximum output power, 20kHz) = 0.008%
The parts used in this module are trimming resistors, low- and medium-power transistors:
HERE VIDEO
Not bad at all, almost high-end! In fact, if you focus only on SOI, then this amplifier is full-fledged HI-END, but this is not enough for the high-end, so it was classified in the good old category hi-fi. Although the amplifier develops only 100 watts, it is an order of magnitude more complex than similar circuits, but the assembly itself will not be difficult if all the components are available. I do not recommend rejecting the circuit values - my experience confirms this.
Low-power transistors may overheat during operation, but there is no need to worry - this is their normal operating mode. The output stage, as already said, operates in class AB, therefore, a huge amount of heat will be released that needs to be removed. In my case, they are reinforced with a common heat sink, which is more than enough, but just in case, there is also active cooling.
After assembly, we are waiting for the first launch of the circuit. To do this, I advise you to read the launch and configuration of Lanzar again - here everything is done in exactly the same way. We do the first start with the input shorted to ground, if everything is OK, then we open the input and sound a sound signal. By that time, all power components must be strengthened with a heat sink, otherwise, while admiring the music, you may not notice how the output stage switches smoke - each of them is very, very expensive.
We finally made our home audio system amplifier sound decent, checked its performance, and assessed the sound quality of the main channel. It's time to add a protection module against accidental short circuits to it so that all the work does not go to waste due to inevitable accidents during its operation. We will also assemble the remaining low-power ULF channels to connect the rear speakers.
UMZCH AS PROTECTION
Initially I thought of using a protection circuit against BRIG , but then reading reviews about triac protection I wanted to try it. The protection blocks were made at the very end, finances were tight then, and triacs and other circuit components turned out to be quite expensive, so we returned to relay protection.
As a result, three protection blocks were assembled, one of them for the subwoofer amplifier, and the other two for the OM channels.
You can find a large number of protection block diagrams on the Internet, but I have tried this scheme several times. If there is a constant voltage at the output (above the permissible level), the protection is instantly triggered, saving the dynamic head. After power is applied, the relay closes, and when the circuit is triggered, it should open. The protection turns on the head with a slight delay - this, in turn, is also an additional insurance and the click after turning on is almost inaudible.
The components of the protection unit may deviate from the specified ones, the main transistor can be replaced with ours KT815G, used high voltage transistors MJE13003- I have a lot of them, in addition, they are quite powerful and do not overheat during operation, so they do not need a heat sink. Low-power transistors can be replaced with S9014, 9018, 9012, even on KT315, the best option is 2N5551. A 7-10 Ampere relay, you can choose any 12 or 24 Volt relay, in my case 12 Volt.
Protection blocks for the OM channels are installed near the transformer of the second inverter, this whole thing works quite clearly, at maximum volume the protection can work (falsely) extremely rarely.
LOW POWER AMPLIFIERS
I spent a long time deciding which amplifier to use for low-power speaker systems. At first I decided to use microcircuits as a cheap option TDA2030, then I thought that 18 watts per channel was not enough and moved on to TDA2050- a more powerful analogue at 32 watts. Then, after comparing the sound of the main options, the choice fell on my favorite microcircuit - LM1875, 24 watts and sound quality is 2-3 orders of magnitude better than the first two microcircuits.
I scoured the net for a long time, but I still couldn’t find a printed circuit board that suited my needs. Sitting at the computer for several hours, we created our own version for a five-channel amplifier on microcircuits LM1875 , the board turned out to be quite compact; the board also has a block of rectifiers and filters. This unit was completely assembled in 2 hours - all components were available by that time.
AMPLIFIER VIDEO
The sound quality of these microcircuits is at a very high level, in the end Hi-Fi, the output power is decent - 24 watts sinus, but in my case the power is increased by increasing the supply voltage to 24 volts, in which case you can get about 30 watts of output power. On the main amplifier board I had space for a 4-channel amplifier on TDA2030 , but for some reason I didn’t like it...
The board for LM is attached to the main ULF board through racks in the form of tubes and bolts. The power for this unit is taken from the second inverter; a separate winding is provided. The rectifier and filter capacitors are located directly on the amplifier board. Already traditional rectifier diodes KD213A. I did not use chokes to smooth out RF interference, and there is no need to use them, since even fairly branded car amplifiers often do not install them. As a heat sink I used a set of duralumin blanks 200x40x10 mm.
A cooler is also attached to the board, which simultaneously removes warm air from this unit and blows away the heat sinks of the inverters. Now that we've completely figured out the electronics of the audio complex, let's move on to mechanics and plumbing work...
The basis of any amateur radio design is a beautiful, comfortable case, especially since it should look decent on a device that takes its rightful place in the living room or your office.
CASE AND INSTALLATION
I struggled with the body for a particularly long time, until one fine day a stranger came to me. In his hands was a device that looked like an old power amplifier. The man introduced himself and started a conversation. It turned out that he knew me well and brought me an unnecessary thing to exchange for an uninterruptible power supply. He didn’t give him an uninterruptible power supply, but he persuaded him to sell the device for 400 rubles. Without thinking twice, he agreed. The device is a compressor from the company TESLA , was in quite working condition, but all I needed from it was a housing that was just right for the amplifier complex.
VIDEO - HOMEMADE AMPLIFIER
The transformers were fixed to the board using especially strong “moment” glue; they were additionally pressed to the board with metal washers (with a rubber gasket so as not to pinch the windings), which had to be painted black so as not to be conspicuous. The washers are secured with bolts with a length of 40 mm and a diameter of 4 mm.
Power buses took almost 5 days. For a long time I couldn’t decide how to make them, from what material and what shape to make them. I tried a lot - aluminum, stainless steel (tires of the required section were available only from the specified metals). Both options were not suitable, there were too many losses, even buses with a cross-section of about 12 mm overheated, in the case of stainless steel there was a high resistance of the section of the used bus, within 5 minutes of operation of the inverters the bus heated up so much that you could easily boil water on it, resulting in losses only in the busbars - a modest 10 Amperes... As a result, a thick stranded wire with a cross-section of 16 mm was purchased and each inverter is connected to the main contact busbars through such a cable. The cross-section of this wire is more than enough, of course, you can get by with a thinner one, but I made it with a reserve, so to speak, just in case.
The cable is connected to distribution buses (there are two such buses) - this is done for ease of installation. A power plus is supplied to each inverter through the distribution bus. The distribution busbars are made of brass, secured to the main board with a bolt and glue (again, for insurance).
The heat sinks were taken from some domestic amplifier, after the first launch, it became clear that they were not enough for such a monster, because all the output stages of the amplifiers are mounted on this particular heat sink. That is why I decided to add active cooling in the form of a cooler.
Initially I thought of bringing the heat sink of low-power amplifiers outside, but then I found duralumin blanks in the attic and decided to make a heat sink out of them. Fortunately, the blanks had threads and there were no problems with their joining. The finished heat sink is attached to the amplifier chassis. A cooler is installed on the board of low-power amplifiers, but not to remove heat from the radiators of this unit, but to cool the power switches of the inverter and rectifier diodes. During operation at low power, the heat sinks of the inverters are cold, but at high powers they overheat quite significantly, since the amplifiers consume up to 700 watts, a considerable part of the power is lost turning into unnecessary heat generation on transistors.
Initially I thought of assembling a simple case, since the amplifier itself was planned for a car. Already at the end of the work I thought seriously about the design and all that came out were completely original solutions. The mixture of bronze and gold carbon fiber, the corporate logo and the design of the front panel are all made by hand. The volume control consists of three main parts; I initially planned to bring the controls of the low-pass filter block outside, but after thinking a little, I realized that the design of the front panel was being spoiled, so I adjusted them in advance to my taste so that I no longer had to open the case. The cutoff frequency is approximately 70 Hz, the volume is at maximum - that's all.
I made brass busbars on the board for ease of installation, so that I don’t have to solder the main power busbars when I need to remove the board. Initially I thought that there would be few power buses, but then, when the amplifier was at the last stage of work, I realized that there would be more wires than planned. In order not to spoil the appearance of the internal installation, I decided to use wires with the same insulation color. I used almost all stranded wires with a cross-section of 2.5 mm; to fasten them I used special strips with a latch; a pack of such mounting strips costs a dollar, one pack was enough for the entire project (100 pcs).
All power parts of the amplifiers were mounted on the main heat sink through mica spacers, so as not to drill a hole for each transistor, I decided to use common steel plates, which are attached to the heat sinks with just one screw. This method presses the transistors quite well against the heat sink, and besides, God forbid, in case of breakdowns it will be convenient to work with the output stages.
And in the final part, we will see how the case looks from the outside, calculate the costs of creating a home amplifier, and also summarize the results of the work.
TOTAL COSTS FOR THE COMPLEX
At first I wanted to remain silent about the costs, but I think many are interested in how much was spent in the end. indicates the total cost of a specific component (for example irfz44(8 pcs) - $12 - total price for all transistors).
Let's start with inverters
Rings (4pcs) - 8$
IRFZ44 (4pcs) - 8$
IRF3205 (4pcs) -10$
BC556 (4pcs) - $2
BC546 (2pcs) - 1$
KD213 (8pcs) - 10$
TL494 (2pcs) 1$
Resistors 3$
Film capacitors - $4
Electrolytic capacitors - $12
AMPLIFIER LANZAR
Transistors
2SA1943 2pcs - 8$
2SC5200 2pcs - 8$
2SB649 2pcs - 2$
2SD669 2pcs - 2$
2N5401 2pcs - 1$
2N5551 2pcs - 1$
Resistors 5 watt - 4 pcs - $3
Other resistors - $4
Polar capacitors - $5
Zener diodes - 2 pcs - $2
OM AMPLIFIERS
2SA1943 2pcs - 8$
2SC5200 2pcs - 8$
Other transistors - $10
Capacitors 10$
FILTER BLOCK
TL072 1pc -1$
TL084 1pc - 1$
Non-polar capacitors - $3
Resistors - $2
Regulators 3pcs - 4$
STABILIZATION BLOCK
Transistors 2$
Zener diodes 13 volt 6pcs - $1.5
Stabilizers 7815 2 pcs - $1.5
Zener diodes 7915 1 piece - $0.7
The rest is $2
PROTECTION BLOCK
Transistors - $2
Relay - for free
The rest -1$
Plugs, sockets and connectors - for free.
AMPLIFIERS ON LM1875
LM1875 - 5 pcs - $18
Diodes KD213A 4pcs 5$
The rest is 3$
OTHER
Glue moment (extra strong) 2 bottles - $4
Epoxy resin 1 bottle - $3
Hot glue (hot glue) 3 sticks 1$
Thermal paste 1 bottle - 3$
Self-tapping screws, screws and bolts $3
Tires (brass) 2 pieces 4$
Power buses $2
Wire 16mm (1 meter) $2.5
Single-core wire 6mm (2 meters) $2
Tulips, head connectors - $5
Heat sinks - for nothing
Foil fiberglass - $10
Etching reagents - $5
Housing - $20
Carbon - $10
Cooler (2 pieces) - $7
ASSEMBLY TOOLS
Most of the instruments are Soviet style. A kilowatt drill from the 70s, which I would not exchange even for the most expensive power tool, it faithfully served my father and was inherited, it has lived in our house for 40 years, I work with it very often and has never failed or broken - respect and bow to the engineers who made it. The hacksaw, also a Soviet model, helped a lot.
Soldering iron- replaced two soldering irons while assembling the amplifier, in the end I used a 25-watt soldering iron for soldering small components, a 60-watt soldering iron for soldering components with thick leads, and a hundred-watt monster for tinning tracks, soldering power buses and much more.
Wire cutters, stationery knife, scissors(I had 2 of them, for wires and plastic). Set of screwdrivers, tweezers(small, medium and large), pliers- in general, it was with their help that we managed to bring the matter to an end.
Taking into account all the small components of the complex about 300 US dollars and 4 months of painstaking work were spent, someone will now think - why is this necessary, because for $300 you can buy a ready-made amplifier. Maybe so, but this amplifier is much more powerful and better than any consumer-class UMZCH - I compared it with many models, including magnad , xplod , ivolga . Secondly, it is completely hand-made, every solder, every screw - everything is done by hand, in the end, the original author's design, which is more reminiscent of the design of expensive tube amplifiers, and at the moment this ULF - the most expensive device in my house.
COMPLETION
Yes, this project took a lot of my time and money, but you know what? I don’t regret it at all, in the end, a really cool amplifier was assembled that can be used both in the car and at home, and the sound quality is 200% better than any industrial audio center of the same class, it’s not for nothing that I used high-quality UMZCH circuits in the complex.
The amplifier is quite suitable for discos in small halls - the colossal power will not let you down even at weddings, all that remains is to make a power supply and pre-amplifiers with all the amenities that I plan for next summer. It took 4 months to assemble, there were difficulties with components and time, which is so in short supply, but with all the components and components available, it can be completed in a much shorter time.
As for the sound quality, I can’t put it into words, you just need to listen once and everything will become clear! The main problems were that everything had to be adapted, cut, etched and mounted into a common block. The whole family thought about the appearance of the front panel, in the end the mother’s version won - it was she who proposed this option, for this and much more - low bow to her - she gave the main ideas, and of course the wife did not stand aside either - she helped and worked almost on par with me.
During the assembly process there were some stages when I abandoned the project, but found the strength and completed it, and today I am proud to present it to your court - health to you, love and patience, always yours KASYAN AKA.
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