LANZAR POWER AMPLIFIER OVERVIEW
Frankly, I was very surprised by the expression SOUND AMPLIFIER, which is gaining popularity so much. As far as my worldview allows me, only one object can act under the sound amplifier - a horn. Here it really enhances the sound for more than a dozen years. Moreover, the horn can amplify the sound in both directions.
As you can see from the photo, the horn has nothing to do with electronics, nevertheless search terms POWER AMPLIFIER is increasingly being replaced by SOUND AMPLIFIER, but the full name of this device AF POWER AMPLIFIER is introduced only 29 times a month against 67,000 requests SOUND AMPLIFIER.
It’s just interesting what this is connected with ... But it was a prologue, and now the fairy tale itself:
The schematic diagram of the LANZAR power amplifier is shown in Figure 1. This is an almost typical symmetrical circuit, which made it possible to seriously reduce non-linear distortion to a very low level.
This scheme has been known for a long time, back in the eighties, Bolotnikov and Ataev cited a similar scheme on the domestic element base in the book "Practical schemes for high-quality sound reproduction". However, work with this circuitry did not begin with this amplifier.
It all started with a PPI 4240 car amplifier circuit that was successfully repeated:
Schematic diagram of the car amplifier PPI 4240
Next was the article "We open the amplifier -2" from Iron Shikhman (the article, unfortunately, has been removed from the author's site). 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 hear a hundred times, so digging through my hundred years of recorded discs, I found the original article and I quote it:
OPEN AMPLIFIER - 2
A.I. Shikhatov 2002
New Approach to the design of amplifiers involves the creation of a line of devices using similar circuit solutions, common components and styling. This allows, on the one hand, to reduce the cost of designing and manufacturing, on the other hand, it expands the choice of equipment when creating an audio system.
New line Lanzar RACK series amplifiers are designed in the spirit of rack-mounted studio equipment. Controls are installed on the front panel with dimensions of 12.2x2.3 inches (310x60mm), and all connectors are on the back. With this arrangement, not only improves appearance system, but work is also simplified - the cables do not interfere. On the front panel, you can mount the mounting brackets and carrying handles included in the kit, then the device takes on a studio look. The ring illumination of the sensitivity control only enhances the similarity.
Radiators are located on the side surface of the amplifier, which allows you to rack several devices without disturbing their cooling. This is an undeniable convenience when creating deployed audio systems. However, when installing in a closed rack, you need to take care of air circulation - install supply and exhaust fans, temperature sensors. In a word, professional equipment in everything requires a professional approach.
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 Lanzar RK series amplifiers is shown in Figure 1. Detailed scheme is not given, since there is nothing original in it, and this node does not determine the main characteristics of the amplifier. The same or similar structure is used in most modern mid range amplifiers. price category. The set of functions and characteristics are optimized taking into account many factors:
On the one hand, crossover capabilities should allow additional components build standard options audio systems (front plus subwoofer). On the other hand, enter full set functions in the built-in crossover does not make much sense: This will significantly increase the cost, but in many cases will remain unclaimed. Performance challenging tasks it is more convenient to assign external crossovers and equalizers, and turn off the built-in ones.
The design uses dual operational amplifiers KIA4558S. These are low noise, low intrinsic distortion amplifiers designed with "sonic" applications in mind. As a result, they are widely used in pre-amp stages and crossovers.
The first stage is a linear variable gain amplifier. He agrees output voltage signal source with the sensitivity of the power amplifier, since the transfer coefficient of all other stages is equal to one.
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 of 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 headroom of the amplifier: an increase in gain of 3 dB corresponds to doubling the power, 6 dB to 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 rajah could not keep his promise: there were no such number of grains on the whole Earth ... We are in a better position: an increase in the level by 18 dB will increase the signal strength "only" 64 times. In our case, 300 watts are available, but not every amplifier can boast of such a reserve.
Further, the signal can be fed directly to the power amplifier, or the required frequency band can be filtered out. 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 HPF is noticeably wider: from 150 Hz to 1.5 kHz. As such, it can be used for wideband operation or for the MF-HF band in a channel-by-channel amplification system. The tuning limits, by the way, were chosen for a reason: in the range from 120 to 150 Hz, a "hole" is obtained in which you can hide the acoustic resonance of the cabin. It is also noteworthy that the bass booster does not turn off in any of the modes. The use of this cascade simultaneously with the high-pass filter allows you to adjust the frequency response in the area of \u200b\u200bcabin resonance no worse than with an equalizer.
The last cascade is with a secret. Its task is to invert the signal in one of the channels. This will allow without additional devices use a bridged amplifier.
Structurally, the crossover is made on a separate printed circuit board, which is joined to the amplifier board using a connector. This solution allows for the entire line of amplifiers to use only two crossover options: two-channel and four-channel. The latter, by the way, is just a "doubled" version of the two-channel and its sections are completely independent. The main difference is the changed PCB layout.
Amplifier
The Lanzar power amplifier is made according to the scheme typical for modern designs, shown in Figure 2. With slight variations, it can be found in most amplifiers of the middle and lower price categories. The difference is only in the types of parts used, the number of output transistors and the supply voltage. The scheme of the right channel of the amplifier is given. The scheme of the left channel is exactly the same, only the part numbers start with one instead of two.
An R242-R243-C241 filter is installed at the amplifier input, which eliminates radio frequency interference from the power supply. Capacitor C240 does not allow the DC component of the signal to enter the power amplifier. These circuits do not affect the frequency response of the amplifier in the audio frequency range.
To avoid clicks at the moments of switching on and off, the input of the amplifier is closed to a common wire with a transistor switch (this node 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 gain, the remaining stages provide current gain. The cascade on transistor Q207 stabilizes the quiescent current of the amplifier. To eliminate its "asymmetry" at high frequencies, it is shunted with a C253 Mylar capacitor.
The driver cascade on transistors Q208, Q209, as it should be for the preliminary cascade, operates in class A. A "floating" load is connected to its output - resistor R263, from which a signal is taken to excite the transistors of the output stage.
Two pairs of transistors were used in the output stage, which made it possible to remove 300 W of rated power from it and up to 600 W of peak power. Resistors in the base and emitter circuits eliminate the effects of technological variation in transistor characteristics. In addition, the resistors in the emitter circuit serve as current sensors for the overload protection system. It is made on the transistor Q230 and controls the current of each of the four transistors of the output stage. When the current through a single 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 equal to 16. Correction capacitors C251, C252, C280 ensure the stability of the amplifier covered by the OOS. The circuit R249, C249 included at the output compensates for the increase in the load impedance at ultrasonic frequencies and also prevents self-excitation. Only two electrolytic non-polar capacitors are used in the audio circuits of the amplifier: C240 at the input and C250 in the OOS circuit. Due to the large capacity, it is extremely difficult to replace them with other types of capacitors.
Power supply The high power power supply is based on field-effect transistors. A feature of the power supply is 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 reduces crosstalk between channels. Each converter has a separate LC filter in the power circuit (Figure 3). Diodes D501, D501A protect the amplifier from erroneous inclusion in the wrong polarity.
Each converter uses three pairs field effect transistors and a transformer wound on 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 uF. The output voltage of the converter is not stabilized, so the power of the amplifier depends on the voltage of the on-board network. From the negative voltage of the right and positive voltages 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 a KIA494 (TL494) chip. Transistors Q503, Q504 power the output of the microcircuit and accelerate the closing of the key transistors of the output stage. The supply voltage is constantly applied to the master oscillator, the switching on is controlled directly from the Remote circuit of the signal source. This solution simplifies the design, but in the off state, the amplifier consumes a small quiescent current (a few 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. The signal from the overload sensor is fed to the other comparator through the shaper on the transistor Q501.
When the amplifier overheats, a high voltage level appears at pin 2 of the microcircuit, the same level occurs at pin 8 when the amplifier is overloaded. In any of the emergency cases, the signals from the output of the comparators through the OR diode circuit (D505, D506, R603) block the operation of the master oscillator at terminal 16. Operation is restored after the causes of overload have been eliminated or the amplifier has cooled below the temperature sensor threshold.
The overload indicator is originally made: the LED is connected between the +15 V voltage source and the on-board network voltage. During normal operation, the voltage is applied to the LED in reverse polarity and it does not glow. 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 starts to glow.
On transistors Q504, Q93, Q94, a power amplifier input blocking device is made for the duration of transients when turned on and off. When the amplifier is turned on, the capacitor C514 is slowly charged, the transistor Q504 is in the open state at this time. The signal from the collector of this transistor opens the keys Q94, Q95. After the capacitor is charged, the Q504 transistor closes, and the -15 V voltage from the power supply output securely blocks the keys. When the amplifier is turned off, transistor Q504 instantly opens through diode D509, the capacitor quickly discharges and the process is repeated in 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 on and overload indicators (not shown in the diagrams). The boards are made of high-quality fiberglass with a protective coating of the tracks and are mounted in a U-shaped aluminum profile case. Power transistors amplifier and power supply are pressed with pads to the side shelves of the case. Outside, profiled radiators are attached to the sidewalls. The front and rear panels of the amplifier are made of anodized aluminum profile. The whole structure is fastened with self-tapping screws with hexagon heads. That, in fact, is all - the rest can be seen in the photographs.
As can be seen from the article, the original LANZAR amplifier itself is not bad enough, but I wanted better ...
Useful on the forums, of course, on Vegalab, but did not find much support - only one person retracted. Perhaps it is for the best - there are no heaps of co-authors. Well, in general, this appeal can be considered Lanzar's birthday - at the time of writing the comment, the board had already been 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 - there was nothing like that in his thoughts and the amplifier could get absolutely any name. However, it became LANAZROM in honor of the LANZAR company, since it is this automotive equipment that falls into that small list 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 of 50 to 350 W, and at powers up to 300 W, UMZCH cof. non-linear distortion does not exceed 0.08% in 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 gain, the remaining stages provide current gain. The cascade on the transistor VT7 stabilizes the quiescent current of the amplifier. To eliminate its "asymmetry" at high frequencies, it is shunted with a capacitor C12.
The driver cascade on transistors VT8, VT9, as it should be for the preliminary cascade, operates in class A. A "floating" load is connected to its output - resistor R21, from which a signal is taken to excite the transistors of the output stage. Two pairs of transistors were used in the output stage, which made it possible to remove 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 of the same batch, the spread in parameters between transistors does not exceed 2% - these are the manufacturer's data. In reality, it is extremely rare for parameters to go out of the three percent zone. The amplifier uses only "single-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 yourself, then it will not be useless to assemble the test stand provided at the end of THIS ARTICLE.
Regarding circuitry, it remains only to add that such a circuitry solution gives one more plus - complete symmetry eliminates transients in the final stage (!), i.e. at the moment of switching on, the output of the amplifier does not have any spikes typical 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 pop 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 where good performance UMZCH and high output power.
Of course, you can praise this amplifier for quite a long time, but it’s not modest to engage in boasting. Therefore, we decided to look at the reviews of those who heard how it works. I didn’t have to search for a long time - this amplifier has been discussed on the Soldering Iron forum for a long time, so see for yourself: Of course, there were also negative ones, but the first one was from an incorrectly assembled amplifier, the second from an unfinished version on a domestic configuration ... Amplifier audio frequency MIND LANZAR based on powerful bipolar transistors will allow you to assemble a very high-quality audio frequency amplifier in a short period of time. Power supply ±70 V - 3.3 kOhm...3.9 kOhm Of course, that ALL resistors are 1 W, 15V zener diodes are preferably 1.3 W By heating VT5, V6 - in this case, you can increase the radiators on them or increase their emitter resistors from 10 to 20 ohms. About the power filter capacitors of the LANZAR amplifier: |
Since this amplifier is quite popular and quite often questions about its self-production come up, the following articles were written:
transistor amplifiers. Basics of circuitry
transistor amplifiers. Building a balanced amplifier
Tuning Lanzar and changing the circuitry
Adjustment of power amplifier LANZAR
Increasing the reliability of power amplifiers on the example of the LANZAR amplifier
The penultimate article rather 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
AMPovichok. YOUTHFUL
AMPovichok. ADULT
BUY TRANSISTORS FOR AMPLIFIER LANZAR |
|
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 slew rate does an excellent job of reproducing even the smallest sounds in the high and mid ranges.
You can talk a lot about the delights of 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 have heard how this amplifier sounds (assembled according to this scheme) gave it the highest rating as a home amplifier for high-quality speakers, and endurance in *close to military conditions* gives a chance to use it professionally for sounding various outdoor events 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 * tempted by good sound *
in the musical soundtrack of the Gregorian-Moment of Peace, the monks' choir sounds so realistic that it seems as if the sound passes 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 the 35ac012 and the like, the speakers get a new breath and even at maximum volume they sound just as distinct.
For example, for lovers 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 opposed to this amplifier, an amplifier on the TDA7294 was taken, which, already at a power of less than 70 watts per 1 channel, was able to overload 35ac012 so that it was clearly audible how the woofer coil beats on the core, which is fraught with damage to the speaker and, as a result, losses.
What can not be said about the *LANZAR* amplifier - even with a power of about 150W 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.
In the musical composition Evanescence - What You Want
The scene is so detailed that you can even hear the beats of the drumsticks against each other And in the composition Evanescence - Lithium Official Music Video
The skip part is replaced by an electric guitar, so the hair on your head just starts to move, because there is simply no *prolongation* of the sound, and fast transitions are perceived as if Formuse 1 hurts in front of you, one moment and YOU are immersed in new world. Not forgetting about the vocals, which throughout the composition brings generalization to these transitions, giving harmony.
In the composition Nightwish - Nemo
The drums sound like shots, clearly and without rumbling, and the peals of thunder at the beginning of the composition simply make you look around.
In the composition of Armin van Buuren ft. Sharon den Adel
We again plunge into the world of sounds that permeate us through and through giving a sense of presence (and this is without any equalizers and additional stereo extensions)
Composed by Johnny Cash Hurt
We again plunge into the world of harmonious sound, and the vocals and guitar sound so distinctly that even the increasing pace of performance is perceived as if we are driving a powerful car and press the gas pedal to the floor, while not letting go, but pressing harder.
With a good sound source and good acoustics, the amplifier generally *does not strain* even at the highest volume.
Somehow a friend was visiting me and he wanted to listen to what this amplifier is capable of, putting on a track in the AAC Eagles - Hotel California format, he turned it up at full volume, while instruments began to fall from the table, the chest felt as if well-delivered boxer punches , the glass rang in the wall, and it was quite comfortable for us to listen to music, while the room was 14.5m2 with a ceiling of 2.4m.
They put 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 the video was made in the LAY-5 format.
If you assemble two LANZAR amps, can you turn them on with a bridge?
You can of course, but first a little lyrics:
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 sources, it remains to be found out how many pairs of output transistors to take.
Theoretically, the total AC output power 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 a 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 only practice shows that in this mode, the crystal simply does not have time to give off heat to the radiator and thermal breakdown is guaranteed, because transistors must be isolated, and insulating gaskets, no matter how thin they are, still increase thermal resistance, and the surface of the radiator is unlikely who polishes to micron precision...
So for normal operation, for normal reliability, quite a few 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 a typical amplifier can produce 300W and we turn on two such amps with a bridge, then what will happen?
That's right, the output power will increase by about two times, but the thermal power dissipated by transistors will increase by 4 times ...
So it turns out that to build a bridge circuit, you will need not 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 master's business ....
Well, several options for printed circuit boards for this amplifier will not be superfluous. There are also author's options, there are ones taken from the Internet, so it's better to double-check the board - there will be a training for the mind and fewer problems during the adjustment of the assembled version. Some options have been fixed, so there may not be any errors, or maybe something slipped away ...
One more question remained unanswered - assembly of the LANZAR amplifier on the domestic element base.
Of course, I understand that crab sticks are not made from crabs, but from fish. So does 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 and the gain cof have a smaller unity gain frequency, so you won’t hear the Lanzar sound. But there is always an alternative. At one time, Bolotnikov and Ataev proposed something similar in terms of circuitry, and it also sounded pretty good:
Details on how much power a power supply is needed for a power amplifier can be viewed in the video below. The STONECOLD amplifier is taken as an example, however, this measurement gives an understanding that the power of the mains transformer can 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 needs a BIPOLAR power supply, since the output voltage is formed from the positive and negative supply arms. A diagram of such a power supply is shown below:
About the overall power of the transformer, conclusions can be drawn by watching the video above, but for the rest of the details I will not make a big explanation.
The secondary winding must be wound with wire, the cross section of which is designed for the overall power of the transformer plus a correction for the shape of the core.
For example, we have two channels of 150 W, 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 power of the transformer must be at least 200 W. When powered by ±40 V into a load of 4 Ohms, the amplifier just develops about 160 W per channel, therefore the current flowing through the wire is 200 W / 40 V = 5 A.
If the transformer has a W-shaped core, then the tension in the wire should not exceed 2.5 A per square mm of cross section - this way the heating of the wire is less, and the voltage drop is less. If the core is toroidal, then the tension can be increased to 3 ... 3.5 A per 1 square mm of the wire 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 wire diameter is D = 2 x √S/π.
At a tension of 2.5 A, we obtain a diameter of 1.6 mm, at a tension of 3.5 A, we obtain a diameter of 1.3 mm.
The diode bridge VD1-VD4 not only has to 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 than more tension, the larger the capacitance, the higher the value of this starting current. Therefore, the diodes must be at least 15 amps 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 amp diodes or a soft start system are needed.
The capacitance of capacitors C3 and C4, based on Soviet circuitry, is 1000 microfarads for every 50 W of amplifier power. For our example, the total output power is 300 W, which is 6 times 50 W, so the capacity of the power filter capacitors should be 6000 uF per shoulder. But 6000 is not a typical value, so we round it up to a typical value and get 6800 microfarads.
Frankly speaking, such capacitors do not come across often, so we put 3 2200 microfarad capacitors in each arm and get 6600 microfarads, which is quite acceptable. The question can be solved a little easier - use one capacitor per 10,000 microfarads
Photo sent by Alexander (Allroy), Novorossiysk
By chance, I got a "modernized" power amplifier "Oda-UM102S". The modernization was carried out by an unknown master so severely that only good "meaty" radiators survived. So I decided to adapt mine to them. new project, which smoothly flowed out due to the desire to try out a new idea in hardware.
History reference
The stereophonic radio complex "Oda 102 Stereo" since 1986 has been producing the Murom plant "RIP". The complex provided reception of mono and stereo transmissions in the VHF range, recording of mono and stereo programs, followed by playback. The complex consisted of 5 functionally completed units: VHF tuner "Oda-102S", cassette recorder-prefix "Oda-302S", power amplifier "Oda UM-102S", preamplifier"Oda UP-102S" and 2 acoustic systems "15AC-213".
Excluded fragment. Our magazine exists on donations from readers. The full version of this article is only available
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 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
Lanzar - high quality transistor amplifier class AB discharge Hi-Fi high power output. In the course of the article, I will explain in as much detail as possible the assembly process and configuration of the specified amplifier in the language of a beginner radio amateur. But before we start talking about it, let's look at the plate with the parameters of the amplifier.
| PARAMETER | power amplifier schematic diagram of power amplifier Lanzar description of work recommendations for assembly and adjustment | ||
| PER LOAD |
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| 2 Ohm |
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| Maximum supply voltage, ± V | |||
| Maximum output power, W with distortions up to 1% and supply voltage: | |||
| ±30 V | |||
| ±35 V | |||
| ±40 V | |||
| ±45 V | |||
| ±55 V | |||
| ±65 V | 240 | One of important parameters- non-linear distortion, at 2/3 of the maximum power is 0.04%, at the same maximum power of 0.08-0.1% - this amplifier can be attributed to the Hi-Fi category of a rather high level. Lanzar is a symmetrical amplifier and is built entirely on complementary switches, the circuitry has been known since the 70s. The maximum output power of the amplifier with 2 pairs of output switches to a load of 4 ohms with a bipolar supply of 60 volts is 390 watts under a sinusoidal signal of 1 kHz. Some strongly disagree with this statement, I personally never tried to remove the maximum power, I managed to get a maximum of 360 watts with a stable 4-ohm load during the tests, but I think it is quite possible to remove the indicated power, of course, the distortion will be quite large and normal operation of the amplifier when trying to remove the specified power for a long time. Amplifier Power is carried out from an unstabilized bipolar source, the efficiency of the amplifier is 65-70% at best, the rest of the power is dissipated in the form of unnecessary heat at the output transistors. The assembly of the amplifier begins with the manufacture of the printed circuit board, after etching and drilling holes for the components, it is imperative to tin all the tracks on the board, additionally it would not hurt to strengthen the power supply tracks with an extra layer of tin. We do the assembly from the installation of small components - resistors, then low-power transistors and capacitors. At the end, we install the largest components - the transistors of the final stage and electrolytes. pay attention to variable resistor, which regulates the quiescent current of the output stage, in the circuit it is designated X1 - 3.3 kOhm. In some versions, a 1 kΩ resistor. I strongly advise you to use this resistor as a multi-turn one, for the most accurate setting of the quiescent current. At the same time, the resistor initially, before installation, must be screwed up (to the maximum resistance). Let's look at the list of necessary components for assembling the specified circuit.
The cost of components is not small, it will cost around $ 40, taking into account all the subtleties, of course, without a power supply. If you want to use a mains transformer to power such a monster, most likely you will have to fork out another $ 20-30, because taking into account the efficiency of the amplifier, you will need a mains transformer with a power of 400-500 watts. The amplifier consists from several main nodes, in theory, the same schematics of the lin known to our grandfathers. The sound initially enters the double differential stage, in fact, this is where the initial sound is formed. All, all subsequent cascades are voltage and current amplifiers. The output stage is a simple current amplifier, in our case two pairs of powerful 2SC5200 / 2SA1943 switches with a dissipation power of 150 watts are involved. The pre-output stage is a voltage amplifier, and the previous helmet built on VT5 / VT6 switches is a current amplifier. In general, cascades that are a current amplifier must overheat quite a lot and need to be cooled. The BD139 transistor (a complete analog of the KT315G) is a control transistor for the quiescent current of the output stage. Resistor R18 (47Ω) plays an important role in the circuit. The sound signal for excitation of the transistors of the output stage is removed from this resistor. The amplifier circuit itself is push-pull, which means that the output (and in other respects all) transistors open at a certain half-wave of the sine, amplifying only the lower or upper half-cycle. Power supply for differential cascades in any self-respecting amplifier, it is supplied stabilized, or it is stabilized directly on the amplifier board, as is the case with the Lanzar. In the circuit, you can see two Zener diodes with a stabilization voltage of 15 volts. The indicated zener diodes can be taken with a power of 1-1.5 watts, you can use any (including domestic ones) Before assembly, carefully check all components for serviceability, even if the latter are completely new. Particular attention should be paid to transistors and powerful resistors that are in the power supply circuit of transistors. The value of emitter resistors 5 watts 0.33 ohms can deviate from 0.22 to 0.47 ohms, I don’t advise anymore, just increase the heating on the resistor. After the end of the amplifier Before starting, I advise you to check the installation several times, the location of the components, blunders from the installation side. If you are sure that you have not gone too far with the ratings, all the keys and capacitors are soldered correctly, you can move on. VT5 / VT6 - we install it on a heat sink, because of their mode of operation, quite a strong overheating is observed. At the same time, in the case of using a common heat sink for these keys, do not forget to isolate them with mica gaskets and plastic washers, the same is the case for other transistors (except for low-power differential cascade keys. After installation, we take a multimeter and set it to the diode continuity mode. We put one of the probes on the heat sink, with the second we touch the conclusions of all the keys in turn, checking the closure of the keys with the heat sink, if everything is correct, then there should be no short circuits. Resistors R3 / R4 - play a lot of important role. They are designed to limit the power supply of differential stages and are selected based on the supply voltage.
These resistors need to be taken with a power of 1-2 watts. Then we carefully connect the power buses and start the amplifier, initially we close the input wire with the middle power point (with ground). After starting, we wait a minute, then turn off the amplifier. check the components for heat dissipation. Initially I advise run the amplifier through a bipolar power supply unit at 30 volts (in the shoulder), while through a series-connected incandescent lamp of 40-100 watts. At the time of connection to the 220 Volt network, the lamp should light up and go out for a short time, if it glows all the time, then turn off and check everything that is after the transformer, the rectifier unit, capacitors, amplifier) Well, if everything is fine, then we unhook the input of the amplifier from the ground and start the amplifier again, not forgetting to connect the dynamic head. If everything is OK, then there should be a small click from the acoustics. Further, without turning off the amplifier, we touch the input wire with a finger, the head should roar, if everything is so, then congratulations! amplifier works! But that doesn't mean that everything is ready and you can enjoy, everything is just beginning! Then we connect sound signal and we start the amplifier at about 40% of the maximum volume, those who do not spare acoustics can turn it on to the maximum. It is advisable to start with modern music, not classics, and enjoy for about 15 minutes. As soon as the heat sink is warm, we begin the second stage - setting the quiescent current of the output stage. For this, the circuit provides a 3.3 kΩ variable, which was discussed earlier. Setting the quiescent current according to the photo After setting the quiescent current, we proceed to the next part - measuring the output power of our amplifier, but this step is not necessary. Capture power output it is necessary under a sinusoidal signal of 1 kHz to a load of 4 ohms. As a constant load, you need to use a resistor immersed in water or a resistor assembly with a resistance of 4 ohms. The resistor should have a power of 10-30 watts, preferably with as little inductance as possible. At this point, the assembly and tuning process has come to its logical end. Printed circuit board exactly our lanzar is in the attachment, you can download it and safely assemble it, it has been tested repeatedly (more precisely, more than 10 times). It remains only to decide - where you will use the amplifier, at home or in the car. In the case of the latter, most likely you will need a powerful voltage converter, which we have repeatedly talked about on the pages of the site. | |
Another summer project. This time I wanted to create a super-powerful amplifying complex for a car. I had several hundred dollars at my disposal, so I could buy new components, and not rummage through the trash for each resistor, as I did last time.
So, the new amplifier had to work from 12 volts, I decided to assemble a complex of Hi-Fi discharge amplifiers. The laznar subwoofer amplifier was completed first, and we will talk about it today.
Lanzar circuit is completely linear - from input to output. The maximum power of the circuit according to the application is 390 watts and the circuit may well develop the indicated power. Like any powerful amplifier, the lanzar is also powered by a bipolar source. The upper peak of the supply voltage is ± 70 V, the lower one is ± 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, the operation of individual schema nodes.
The limiting resistors of the differential stages are selected based on the nominal value of the supply voltage, the selection of the nominal value is given below (the power of the resistors is 1 watt, thanks to det for the plate).
| Power supply ±70 V | 3.3 kΩ…3.9 kΩ |
| Power supply ±60 V | 2.7 kΩ…3.3 kΩ |
| Power supply ±50 V | 2.2 kΩ…2.7 kΩ |
| Power supply ±40 V | 1.5 kΩ…2.2 kΩ |
| Power supply ±30 V | 1.0 kΩ…1.5 kΩ |
Lanzar amplifier circuit board.lay
Zener diodes are designed to stabilize the supply voltage of differential cascades. 15 volt zener diodes with a power of 1-1.3 watts should be used.
It is desirable to use transistors that are used in the circuit, although I had to use analogues.
Coil - wound with a wire of 0.8 mm on a drill with a diameter of 10 mm. Coil turns are glued with superglue for reliability.
The emitter resistors of the output transistors are selected with a power of 5 watts, during operation they may 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 works in class AB, so a serious heat sink is needed to cool the transistors of the output stage, in my case, a radiator from the domestic amplifier of radio engineering U-101 was used.
It is better to take a 1kΩ trimmer resistor with a multi-turn one, they adjust the quiescent current of the output stage, a multi-turn resistor allows you to make very precise settings.
All transistors of the output stage are strengthened to the heat sink through insulating plates and washers. Before starting, carefully check for short circuits of the transistor leads to the heat sink.
The input capacitor with a capacitance of 1 uF can be chosen to your taste, but since the lanzar is more used to power the subwoofer channel, it is advisable to take a larger capacitor capacitance.
All film capacitors are 63 volts or more, they should not be a problem, 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 the main parameters of the amplifier are presented below.
| PARAMETER | PER LOAD | ||
| 8 ohm | 4 Ohm | 2 Ohm (bridge to 4 ohms) |
|
| 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 coff, dB | 24 | ||
| Non-linear distortion at 2/3 of the maximum power, % | 0,04 | ||
| Output signal slew rate, not less than V/µS | 50 | ||
| Input resistance, kOhm | 22 | ||
| Signal-to-noise ratio, not less than, dB | 90 | ||
It is not advised to raise the supply voltage rating more than ± 60 V, but since I am a fan of force majeure situations, I applied ± 75 Volts to the circuit, removed about 400 watts, although everything began to heat up on the board, I think it’s not worth repeating my experience, perhaps I was just lucky (at the same time, I replaced the diff-cascade resistors with 4 kOhm).
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 use and setup
The first run of the amplifier should be done with the INPUT SHORTED TO GROUND, so there is less chance of burning something if the amplifier is not assembled correctly or there is a problem with the operation of the components. CHECK THE INSTALLATION CAREFULLY before starting. Observe the polarity of the power supply, the pinout of the transistors and correct connection zener diodes, if turned on incorrectly, the latter work like a semiconductor diode.
Power Supply- for starters, you can use a low-power power supply unit watts per 1000. It is desirable to supply power in the region of bipolar 40 volts. When using mains transformers, it is advised to use a capacitor bank with a capacitance of 15.000uF per shoulder, and preferably up to 30.000uF. When using switching power supplies, 5000uF will be enough.
In my case, the amplifier must be powered by a switching voltage converter, so I used a block of 5 capacitors with a capacity of 1000uF (each), i.e. there is a working capacitance of 5000 microfarads in the shoulder.
When using a network transformer, the secondary winding is connected to the network through a series-connected incandescent lamp, this is also an additional precaution.
We start the amplifier, if there were no explosions and smoke effects, then we leave the amplifier on for 10-15 seconds, then turn it off and check the heat dissipation on the transistors of the output stage 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 has worked.
Next, you can attach a heat sink to the outputs and turn on the amplifier to the music. In general, for amplifiers of this type, a preamplifier is needed, when low-power signals are applied to the input (for example, from a PC, player or mobile phone) the amplifier will not sound very loud, since the input signal rating is clearly not enough for maximum power. During the experiments, he gave a signal from music center and I advise you too.