Pair skating needs technical progress, and Alexandra Trusova can become its engine, as she has already done in women's singles. If anyone has the power to shift the most conservative look of figure skaters, it would be our Russian rocket. And it seems that she herself is not averse to setting new goals for herself. She teaches todes, lifts, and even on parallel jumps and cantilevers, she ate the dog!
Does Sasha really intend to get into a couple and spin quads interspersed with quadruple throws?
After the Olympics, did Trusova want drastic changes?
Alexandra Trusova took her defeat to Anna Shcherbakova at the Beijing Olympics hard. Five quadruple jumps brought her victory in the free program, but they were not enough for gold in the overall standings. Silver is a great result, but having achieved such an incredible achievement, Sasha was rightly disappointed in figure skating. At least in the women's singles. And this disappointment turned out to be so great that she even threatened to never go on the ice again. The next day, Sasha calmed down, but her frustration clearly remained: at the press conference after the award ceremony, she did not show her medal, despite requests from journalists. And about her plans to compete at the World Championships she said mysteriously: “You’ll see.”
It is clear that all these are emotions. But perhaps, having never won a single adult title, despite her technical superiority over her rivals, Sasha decided to try herself in another form - pair skating? And at the same time carry out a revolution in it, like the girls? Why not?
She is only 17 years old, and careers in pairs skating tend to be long. With desire and the right amount of perseverance, anything is possible. Sasha is definitely not lacking in hard work and diligence, and as for desire... It seems that everything is fine with him: the queen of quads has already tried herself as a guy and learned a couple of elements: todes and high support. And, by the way, they turned out great for her!
“I hate this sport. Never again in life." The most striking quotes from the 2022 Olympics
Power amplifier by Alexander Trusov
I managed to get acquainted with Alexander and his development at the RosHiEnd-2013 Exhibition, where he presented his Esatto . There were no colorful brochures or advertising brochures next to the exhibit - for Alexander, designing audio equipment is more of a hobby than a commercial project, but my attention was attracted by several photographs laid out on the table, apparently taken to show visitors to the Exhibition what the amplifier had inside. And there was something to show: the design looked carefully thought out, and the execution was almost flawless. To top it all off, the PA was designed and executed as ultra-wideband and ultra-fast, which clearly indicated a high level of developer.
It is not surprising that there was a desire to listen to this device at home. We exchanged phone numbers and a month later we arranged to audition the amplifier in my audio system.
The 2013 product had the following main parameters:
Output Power: 150W RMS per channel.
Output voltage slew rate: 260 V/µs (current OOOS) Intermodulation distortion: 0.0007%, at 100 W output power. Bandwidth at frequency response roll-off -3dB: DC - 1200000 Hz
DC amplifier (DCA)
600 ohm volume control Quiescent current: 360 mA
Amplifier Esatto model 2013
It was difficult to make any complaints about the sound of the Esatto on the shelves, retained all the details of the phonogram both at very low and at very high volumes. The design and workmanship of the case were consistent with the internal contents.
Internal layout of the Esatto amplifier one of the first modifications
From my point of view, this was the best designer amplifier that I have ever auditioned - natural Hi-End, in the best sense of this phrase. When compared with industrial products, I even find it difficult to choose a price category in which to look for an analogue in terms of sound quality - somewhere very high, I think. However, Alexander did not stop there and almost immediately after the Exhibition began work on the further development of the project. The process turned out to be not as fast as we would like - the readiness for the next Exhibition in 2014 was not complete, which is partly explained by the fact that the PA was noticed by the audio community and several speaker manufacturers wanted to demonstrate their acoustics with A. Trusov’s PA. That is, by the beginning of the 2014 Exhibition, Alexander needed to have time to build several additional copies of the 2013 version, in his free time from his main work.
Despite the fact that the same version of the amplifier was again shown at RosHiEnd-2014, its “procession” was triumphant: the device was recognized by listeners and colleagues as one of the best at the Exhibition - its mesmerizing sound, coupled with wonderful four-way speakers S.D. Father and Viktor Lukhanin were noted by almost everyone, and Salon AV magazine awarded Alexander an honorary diploma.
Many people ask the question: “What’s inside it?”
Internal layout of Esatto II
It is no secret that the circuit design of Alexander Trusov’s amplifier originated from the classical topology of a PA with current feedback, which many have tried to use in their designs. About 15 years ago I took it on, but to no avail - I didn’t have the patience to bring it to fruition, and I still didn’t have enough experience. As practice shows, the classical scheme is quite capricious, unstable and, in my deep conviction, does not represent anything particularly outstanding. However, it has very serious potential, which Alexander took advantage of, redoing everything in his own way, spending several years on prototyping and experiments. Particular attention was paid to the design and power supply of the PA - the influence of these factors on the sound is difficult to underestimate. The 2013 version already had a fully stabilized power supply for the input and driver stages, a block layout that ensured the shortest signal path from input to output, a high energy intensity power supply, a ladder-type volume control with low input impedance, and a relay input selector. All operating modes were controlled from the remote control.
For RosHighEnd-2015, Alexander has already prepared a new version - Esatto-II , which has noticeable differences in the circuitry, design, and power supply of the cascades:
1. The PA is equipped with a new low-impedance volume control with constant input and constant output impedance.
2. The power supply of the output stages is now also stabilized. Discrete stabilizers of his own design are used throughout, with a high stabilization coefficient and low losses.
3. The performance of the amplifier stages has been significantly increased, and the PA bandwidth has also been expanded
4. The energy consumption of the power supply and the quiescent current of the final stages have been increased
5. The amplifier now has no overall feedback, but nonlinear distortion remains low, thanks to the use of new circuitry and topology.
6. The device received an almost unique option, implemented using a modified Huxford corrector - the ability to change the output resistance value from the remote control, up to its negative values. This allows you to quickly configure the amplifier to work as efficiently as possible with specific speakers and speaker cables.
7. The design of the case and controls has been improved - along with the remote control, you can now use a multifunctional and comfortable handle, and the case itself is almost a work of art and looks decent next to the most famous brands.
Esatto II
Technical parameters of the new mind:
Analog inputs: linear 3 RCA (UPT) Sensitivity: 1.6 V Gain: 30 dB Nominal output power: 2 x 100 W/8 Ohm, 2 x 196 W/4 Ohm Peak load current: 2 x 32 A Output impedance: from + 0.1 Ohm to - 0.22 Ohm (adjustable remotely in real time) Load damping factor: 8 Ohm from 80 at (+ 0.1 Ohm) to tending to infinity at (- 0.22 Ohm) Bandwidth at roll-off -3 dB: DC - 3200000 Hz Linearity of the phase response in the frequency range 0 Hz - 20 kHz: -1 degree at 19737 Hz. THD at rated output power: 0.037% - 20 kHz.
Quiescent current: 520 mA - 800 mA (depending on the number of installed pairs of output transistors)
Dimensions: 430 x 180 x 395 mm Weight: 48 kg
From the point of view of the demand for amplifiers by manufacturers of speaker systems, the RosHighEnd-2015 exhibition was no exception - we again saw and heard the successful performance of this device in several setups - MTUSI Acoustic Center, Illuminati Laboratory, S.D. Laboratory. Dad and in his own setup LLC "A.T." - also with acoustics by S. D. Batya and Viktor Lukhanin.
Esatto II at an audition in the "Exclusive" hall of the MTUSI Congress Center with four-way speakers S.D. Dad and Viktor Lukhanin
The amplifiers presented by A. Trusov at the Exhibition had some differences among themselves and belonged to different modifications of 2015, but I was able to listen to the latest and most technically advanced model after the Exhibition, in a home audio system.
The listening revealed the unequivocal superiority of the new PA over previous models, which confirmed the feasibility of using circuitry and design innovations. Testing the amplifier was difficult - I kept catching myself just listening to music. This is a very good sign and indicates the highest quality of the component. It doesn’t make much sense to talk about musical resolution, stage construction, localization of sound sources and other audiophile sound parameters in relation to this amplifier - it’s all there in such abundance that it’s taken for granted and people don’t even focus on it. The only thing that was subject to discussion based on the result of the audition was the presentation of musical material, the ability to convey the emotions of the performers, and show the sound engineer’s intention. The amplifier coped with all these tasks easily and naturally.
The option to remotely change the output impedance of the amplifier deserves a separate story. In principle, you can set the value to zero and listen to music - everything will be fine, but if you still start tuning for specific speakers, then you can select by ear the optimal position of the control, in which the sound will gain maximum freedom, and your hand with the remote control in your hand it will freeze in one position corresponding to the moment in time of entering audio nirvana :)
The amplifier has already been connected to several audio systems and it was noticed that on different speakers the optimal values of the output impedance of the final stage have significant differences. Statistics are being collected little by little, but we can already say that the presence of such a function in a power amplifier is definitely useful.
It must be said that the research in the field of high-quality sound reproduction that A. Trusov is engaged in, regardless of the expenditure of time and money, inspires respect - all design ideas and circuit solutions are checked and tested by Alexander on high-quality “hardware” models, although, with such simulation programs, Alexander also owns and actively uses Multisim or MicroCap.
It took A. Trusov more than 5 years to create such a perfect apparatus, but the time and effort were clearly not wasted. I would like to congratulate Alexander on the birth of an exclusive design and wish him further success in this painstaking creative work!
My channel on Yandex Zen
Sincerely, O. Shamankov ( Prophetmaster )
Trusova modernized the todes at the rehearsal of demonstrations
During the rehearsal for the gala show at the Olympics, Alexandra impressed with her desire to learn how to make todes. Vladimir Morozov helped her master one of the basic elements of pair skating, who, together with Evgenia Tarasova in Beijing, won silver in the individual tournament among pairs. Some may consider this to be ordinary fun, but Sasha and the quads jump playfully, without forgetting about the quality.
It's the same story with Todes. The figure skater was really having fun, but she performed the element diligently: the video from the training shows how she stretched her body and arms and concentrated. And behind the scenes, Maxim Trankov praised her: “Now it was good.”
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That is, Sasha’s goal was not just to try, but to have it turn out correctly and beautifully. High bar for entertainment, though. And having mastered the standard todes, Sasha complicated her task: she made it together with Zhenya Tarasova! I wonder what they named this element? Double todes? Here it is - the reformist spirit of the Russian rocket!
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Sasha's parallel quads and cantilevers are excellent!
Everyone knows that Sasha loves to jump. And not just alone. At any opportunity, she enjoys doing parallel jumps with other skaters. And most often these are male skaters. There are no such demonstration performances where she would not team up with someone to perform her favorite quads together. Among Sasha’s “jumping” partners more than once were such titans among the guys as Nathan Chen and Yuzuru Hanyu. And for most people, jumping with her is a real success and privilege; you have to try very hard not to get lost against her background. And, of course, mastering quadruples: everyone is used to parallel triples - Sasha goes further.
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Can you imagine what changes await pair skating if she switches to it? Parallel quads, four-turn emissions are something that not everyone dares to think about. What about a parallel cantilever? Sasha also loves to perform her signature spiral in pairs. True, her choice here is extremely limited: few can compare with her in the skill of its execution.
“You will definitely have a gold medal.” Kovalchuk's touching promise to Trusova
Master class on support and partner selection
After the Olympics, Sasha quickly returned to training at Khrustalny, but did not stop experimenting with pair skating. On her Instagram page, she published a video of herself skating together with Alexei Tikhonov. He lifted her up high and spun her around on the ice. The girl looked very happy: she was beaming with a smile. And how carefully and confidently she left the support! She stretched out her leg and spread her arms properly. A little more practice - and it will be sweet!
Sasha added a caption to the video with gratitude to Alexei Tikhonov.
“Thank you to Alexey Tikhonov for the master class!” – wrote Trusova.
Surely the master class involved more than just support: Sasha taught something else. For example, the same emissions - with her space jumps, she would have no equal in them. Fans of the figure skater are already speculating in the comments about who to choose as her partner. Among the proposed options: the same Nathan Chen, Yuzuru Hanyu, and from our guys - Makar Ignatov and Maurice Kvitelashvili.
Integrated amplifier AT Audio Esatto II
It’s not very often that Russian manufacturers pamper us with their equipment. Of course, at the “Russian Hi-End” exhibition you can see quite interesting developments, but they are produced, albeit in small ones, but still in series - one, two, and counting. Today we will listen to just such a device, which turned out to be extremely interesting.
By the way, it is not by chance that it is mentioned here - the AT Audio company, represented by its founder Alexander Trusov, has repeatedly participated in the “Russian High-End” and last year was awarded a diploma from our magazine. And this year, a fair portion of the acoustics at the exhibition were demonstrated with AT Audio amplifiers. The reasons for this choice will become clear below.
The display located in the center shows the volume level and (Sic!) the value of the output impedance, which is stepwise adjustable from +0.1 to -0.22 Ohms.
The Esatto II model (translated from Italian as accurate, correct) is available in three modifications in the price range from 250 to 750 thousand rubles. They differ mainly in power output and quality of components.
Our copy has a power of 2 x 100 W (8 Ohms) and costs 499 thousand. This is a heavy – almost 50 kg – and impressive in size device with a classic design for an amplifier. The display located in the center shows the volume level and (Sic!) the value of the output impedance, which is stepwise adjustable from +0.1 to -0.22 Ohms. At the same time, the damping factor at an 8-ohm load varies from 80 to almost infinity, which allows you to select the desired bass character for any speaker system. Adjustments and switching, including switching of three linear inputs, are accessible from the remote control and are carried out using Omron bistable relays.
“A good amplifier, in my understanding, with all its accuracy and detail, should not be conducive to sound analysis; its task is to captivate you with music.”
The total capacitance of the filter capacitors in each arm is about 100,000 µF, power supply for all stages, incl. and weekends, stabilized. Thanks to this, when the load impedance decreases from 8 to 4 ohms, the output power increases from 100 to 196 W. The quiescent current of the output transistors is 0.5 A, i.e. up to approximately 4 W they operate in class “A”.
The amplifier design is absolutely symmetrical. A powerful toroidal transformer is hidden in the center under a thick steel casing, the channel boards are mounted vertically on impressive heat sinks. The design is universal - depending on the output power, you can increase the capacity of the filter capacitors and the number of output transistors in each arm. The internal connections are made of copper monocore with a diameter of 0.63 (input circuits) and 1.7 mm (output and supply circuits), only protection and indication boards are connected by loops.
While the system was warming up, I asked Alexander to tell me a little about himself and his amplifier.
— Why did you decide to start designing audio equipment?
— In 1998, during the period of my passion for car audio, I met Dmitry Svoboda, the organizer of the “Russian High-End” and visited his exhibition for the first time. Alexander Yuryev’s “Storm” amplifier made a very strong impression then – this gave the first impetus. But special progress has occurred over the past three years, and it has become clear in which direction to move.
- And which one?
— A good amplifier, in my understanding, with all its accuracy and detail, should not be conducive to sound analysis; its task is to captivate the music and have an emotional impact. But if you want, even in a large orchestra you can hear every instrument. Several years ago, Dmitry Svoboda and I made a bet that I would make a fast and dynamic transistor amplifier with the stage depth of a competent single-ended tube amplifier. At the last exhibition, he admitted that I won the argument.
— How did you achieve scene depth and emotionality? Feedback experiments?
— Any, even fast current feedback, does not give the desired effect. Objective parameters are improved, but at the same time, quiet after-sounds are “eaten up,” which to a greater extent determine the depth of the scene. After all, what happens: the response of the low-frequency head goes to the output of the amplifier, is captured by the OS loop, which begins to react to something that was not in the original signal. Hence the tightness, the flat stage. My amplifiers do not have general feedback, only local feedback is used. In addition, there are no capacitors in the audio path; it is a UPT from input to output. There are no electrolytic capacitors in the power supply decouplings of the input and driver stages; the circuit design makes it possible to use film capacitors.
— Are the output transistors bipolar or MOSFET?
— Lateral MOSFETs that do not require temperature stabilization. They provide subjectively deeper bass, which is felt even on compact acoustics.
— Where are iron and printed circuit boards made?
— Body parts are milled on CNC coordinate machines. Painting is with automotive semi-matte enamel with a ceramic additive, resulting in a very durable and beautiful coating. Printed circuit boards are ordered either from Rezonit or from SMT Service.
— How do you avoid fake components?
— The entire element base is imported, purchased from large and reliable suppliers. The chance of getting fake parts is almost zero. Transistors are matched in pairs, operational amplifiers in the voltage amplifier are in metal cases costing about 14,000 thousand rubles apiece; these cannot be counterfeited. Capacitors - Panasonic, Nichicon and even Black Gate, depending on the wishes of the customer.
First, we connected ATC SCM-40 acoustics to the amplifier using Atlas Mavros Ultra cables - impressive three-way speakers with a closed design. I launch the Tutti “sighting” disk [1] and, intrigued, listen to the spatial perspective. It is truly unusual - the symphony orchestra is clearly divided into two rows deep, and more distant plans can be discerned, although the virtual images in them are blurred. But I noticed this only briefly, because attention instantly switched to another aspect of the sound - the incredible liveliness of the presentation. It was not just accurate, detailed and dynamic, but lively, I would say even with enthusiasm. The orchestra played festively and brightly, in an unusually transparent atmosphere. Only one moment spoiled the whole picture - a monotonous rumble in the upper bass region, like the rumble of distant thunder. It was possible to eliminate it by selecting the output impedance of the amplifier, but at the expense of the freedom and openness of the lower register. In addition, Alexander was not delighted with the construction of the stage - in his opinion, there should be more clear sound plans.
After a few trial shifts, the ATC SCM-40s were replaced with Dynaudio Contour S3.4 LEs and the copper Mavros Ultras with silver Audio Note AN-SPXs. We were able to select a more suitable power cable for the amplifier. I must note that Esatto II turned out to be extremely sensitive to such experiments - it responded to each replacement with new nuances of sound.
The stage stretched so wide that individual sources were outside the stereo frame.
The newly rebuilt system showed a very interesting result. The stage stretched so wide that individual instruments were outside the stereo range. The background went into depth, taking with it some of the virtual objects from the middle, which were already clearly focused and had the correct proportions. The general character of the sound has also changed - it has become stricter, more focused and more precise, especially in the upper bass area. The lower register, on the contrary, relaxed slightly, which is why the presentation did not seem too restrained. And the liveliness noted above organically complemented the overall picture.
Acoustics with a sensitivity of 86 dB did not cause any difficulties for the amplifier even on the loudest fragments, although it got quite warm. There was no coloration or harshness in the upper range - the sound remained just as clear and rich across the entire spectrum.
And yet, there is a feeling that Esatto II did not show its full potential - it is possible that with such sensitivity to the most seemingly insignificant changes in the system, more interesting results could have been obtained. And the very ability to adapt the amplifier to the nature of the speaker systems and the characteristics of the room is a very important property.
COMPONENTS
Naim CDX-2 CD player
Acoustic systems:
- ATC SCM-40
- Dynaudio Contour S3.4 LE
Cables:
- interconnect Atlas Asimi Ultra
- acoustic Atlas Mavros Ultra, Audio Note AN-SPX
- network Cardas Quadlink Power Cord
Music:
- “Tutti! Orchestral Sampler". 24 bit HDCD Reference Recordings, 1997.
- The Rolling Stones, "Steel Wheels". Virgin, 1989
- Great Cover Versions. Inakustik, Reference Sound Mastering, 2013
- Stanley Clarke, Al Di Meola, Jean-Luc Ponty, "The Rite Of Strings". Gai Saber, 1995
- Noisia, "Split the Atom". 2 CDs, Mau5trap, 2013
Acoustics with a sensitivity of 86 dB did not cause the slightest difficulty for the amplifier even on the loudest fragments.
Esatto II
Manufacturer: AT Audio (Russia)
www.at-audio.su
Line inputs: 3 x RCA || Rated output power at 8/4 ohm load resistance: 2 x 100/2 x 196 W || THD at rated output power: 0.034% (20 kHz) || Peak load current: 2 x 32 A || Output Impedance: 0.1 to –0.22 Ohm || Damping factor (8 ohms): 80 to infinity || Phase linearity (2 Hz – 20 kHz): -1 deg. || Boost frequency range (+0/-1 dB): 2 Hz - 1.2 MHz || Sensitivity: 1.6V || Gain: 30dB || Maximum power consumption: 650 VA || Dimensions: 430 x 180 x 395 mm || Weight: 48 kg || Price: 499,000 rub.
The editors thank the staff of the AVComfort Center salon for their patience and assistance in conducting the audition.
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Tags: AT AudioATCAtlasCardasDynaudioEsattoNaim
It was not in vain that Tutberidze started working with couples
By the way, Alexandra Trusova does not need to switch to another coaching staff for the sake of pair skating. This season, Eteri Tutberidze showed that she is capable of coaching couples. With the help of additional specialists, of course, but even with this everything is in order at Khrustalny: Maxim Trankov and Pavel Slyusarenko joined there along with the couple Evgenia Tarasova and Vladimir Morozov. There is someone to teach all the technical intricacies and nuances. And Zhenya and Vova will become excellent senior comrades and role models.
In general, the Russian Rocket has every chance of achieving success in pairs skating. He will rock parallel quads, carry out technical reforms, set new records - and no one will be outdone!
And yet, no matter what prospects the transition to pairs promises for Sasha, she is still very much needed in women’s singles. I landed five quads – it’s time to take the long-awaited titles. And she should definitely be able to do a triple axel at competitions. So Sasha doesn’t need any radical changes in his sports career before the Olympics in Milan. But then you can extend your career in another form and continue to delight the fans: not alone, but hand in hand with a reliable and strong partner.
Ageev's amplifier is simple, powerful and does not require configuration
Schematic diagram and description of a power amplifier using one op-amp and four transistors.What does a novice radio amateur need if he wants to assemble a powerful and high-quality audio amplifier?
And for this you don’t need so much: ❶ a head with an idea – 1 piece, ❷ a soldering iron with a tip and preferably solder – 1 piece, ❸ paired hands from the right place – exactly two, ❹ Several non-scarce and, of course, inexpensive, and better than “garbage” parts, ❺ Well, the hedgehog understands - the electrical circuit is time-tested, and preferably does not involve any complex settings and magical dances with tambourines.
That is why my choice fell on the circuit of a respected specialist in the field of audio engineering, Alexander Ageev, who published a simple, high-quality and reliable amplifier with a minimum number of transistors in Radio magazine, No. 8, 1982. The amplifier has proven itself excellent in the amateur radio community and continues to do so for almost 40 years!
Fig. 1 Schematic diagram of a thermostable power amplifier by A. A. Ageev
A distinctive feature of the Ageev UMZCH is its extreme simplicity and high temperature stability, which allows the operation of output stage transistors at junction temperatures close to the maximum permissible.
The author proposed two variants of the device - with an output power of 25 and 60 W (the ratings of the elements and supply voltage for the latter are indicated in parentheses). Zener diodes V6 and V7 are not used in ULF with an output power of 25W.
Basic parameters of the amplifier:
- Rated output power at 4 Ohm load, W……………. 25 (60)
- Rated input voltage, V………………………………………….. 1 (1)
- Harmonic coefficient, %, at frequency, kHz: 1 kHz ………….. 0.1 (0.1) 2 kHz ………….. 0.14 (0.55) 10 kHz ………….. 0.2 (0.9) 20kHz ………….. 0.35 (1.58)
- Intermodulation distortion coefficient, %………………….. 0.3 (0.47)
- Frequency band, Hz…………………………………………….. 20 – 150,000 (100,000)
- Output voltage slew rate, V/µs……………………….. 8 (8)
- Input impedance, kOhm………………………………………………………. 150
The signal voltage amplification stage is made on op-amp A1.
As can be seen from the diagram, part of the output signal is supplied to its power circuit through the circuit R6C3C4R4R5. As a result, the voltages at the power terminals of the op-amp at the maximum signal are shifted (relative to the common wire) in the corresponding direction and the range of the output signal of the op-amp increases significantly. This technique is called “floating power” and allows you to obtain a voltage swing at the output from the op-amp - up to 30 volts of amplitude value. This, in turn, makes it possible to obtain up to 60 watts of power at the output of repeaters VT1...VT4. Zener diodes V6, V7 together with circuit elements C3C4R4R5 provide stabilization and filtering of supply voltages. The output stage is based on the circuit of the so-called “parallel” amplifier, which has found application in a fairly large number of designs of various UMZCH. The main feature of such a cascade is its excellent thermal stability, provided there is good thermal contact between all transistors. To improve the amplitude characteristics, a diode V5 and a resistor R8 are connected between the bases of transistors V3, V4. How this improvement occurs is described in detail in the author's original article (Radio-08-1982).
Details and design:
The specified parameters were obtained when the amplifier was powered from a stabilized source. If the source is unstabilized, the supply voltage must be reduced by 20%.
Transistors V1, V3 and V2, V4 are mounted in pairs on plate heat sinks measuring 80 X 70 mm, made of 2 mm thick aluminum alloy sheet, anodized black. Before installation, the cooling surfaces of the transistors must be lubricated with CIATIM-201 lubricant. To ensure reliable thermal contact during the entire period of operation, it is necessary to place split lock washers under the nuts. An amplifier with the specified heat sinks is operational at ambient temperatures up to 35°C. The quiescent current (at normal temperature - about 50 mA) increases when warmed up by no more than 15%.
Instead of the K140UD8A op-amp, you can use the K140UD8B, K140UD6, K140UD10, K140UD11, K544UD1, K574UD1 op-amp in the amplifier.
The L1 coil can be wound on a frame with a diameter of 7 and a length of 25 mm. In this case, it should contain 30 turns of PEV-2 - 1.0 wire, wound in two layers.
The printed circuit board and arrangement of elements for the Ageev amplifier circuit, published in the journal Radio-08-1982, are shown in Fig. 2
Fig.2 Printed circuit board and arrangement of amplifier elements A. A. Ageev
Setting up:
As already mentioned, if the parts are in good working order and there are no installation errors, a properly assembled amplifier does not require adjustment.
