Circuit design using stabilization mode.

Golovna

Output cascades based on "double"

As a result of the signal, we will use a generator with an output support that is rebooted (from 100 Ohms to 10.1 kOhms) with a voltage of 2 kOhms (Fig. 3).
Thus, when testing the VC at the maximum output support of the generator (10.1 kOhm), in any world we will bring the operating mode of the tested VC closer to a circuit with an open-loop feedback loop, and in another (100 Ohm) - to a circuit with a closed-loop feedback loop.

The main types of stock bipolar transistors are shown in Fig.

4. Most often in the VK there is a fixed Darlington transistor (Fig. 4 a) based on two transistors of the same conductivity (Darlington “double”), at least a storage transistor Shiklai (Fig. 4b) with two transistors of different conductivity with strum negative OS, and even more recently - a Bryston storage transistor (Bryston, Fig. 4c).

"Diamond" transistor - a different type of folded Shiklai transistor - shown in Fig.

The Mensch scheme is popular with VK (Fig. 18).

Since the beginning of the development of circuit design for transistor UMZCHs, quasi-complementary output stages have been popular, with the upper arm following the Darlington circuit, and the lower arm following the Sziklai circuit.

However, in the cob version, the input support of the VC arms is asymmetrical, which leads to additional complications.

A modified version of such a VC with a Baxandall diode, as the base-to-emitter junction of the transistor VT 3, is shown in Fig.

20.

In addition to the above-mentioned “two”, there is a modification of the Bryston VC, in which the input transistors are equipped with transistors of the same conductivity, and the collector strum with transistors of a different conductivity (Fig. 22).

A similar cascade can be implemented on field-effect transistors, for example Lateral MOSFET (Fig. 24).
The hybrid output stage behind the Schikla circuit with field-effect transistors as the output is shown in Fig.
28.
Let's take a look at the circuit of a parallel booster using field-effect transistors (Fig. 30).
As an effective way of moving and stabilizing the input support of the “double”, it is recommended to use a buffer at its input, for example, an emitter repeating with a strum generator in the emitter lancus (Fig. 32).

From the examined “two”, VK Szyklai was found to be the highest in the deviation phase and smooth transmission.

High-voltage UMZCHs often have tri-stage structures: Darlington “triples”, Shikla with output Darlington transistors, Shikla with output Bryston transistors and other combinations.

One of the most popular output stages at the moment is a VC based on a Darlington storage transistor with three transistors (Fig. 39).

In Fig.

41 VK readings from the alignment of the cascades: the input repeaters simultaneously work into two cascades, which, in turn, also work into two cascades of the skins, and the third stage of switching on the outer output.

As a result, at the output of such a VC there are four different transistors.

The VC circuit, including the output transistors and the Darlington storage transistors, is shown in Fig.

Often, in order to increase the voltage in the UMZCH, separate provisions are made, advanced by 10...15 V for the input stage and boosted by voltage and reduced for the output stage.

In this case, in order to reduce the output of the output transistors and reduce the intensity of the leading ones, it is necessary to replace the drying diodes.

Let's take a look at this option with the butt modification of the circuit in Fig.

39. When the input voltage is higher than the life voltage of the output transistors, the additional diodes VD 1, VD 2 are opened (Fig. 59), and the active current of the base of transistors VT 1, VT 2 is discharged onto the life bus to end transistors.

In this case, it is not allowed to increase the input voltage above the level of life for the output stage VK and the flow of the collector of transistors VT 1, VT 2 is reduced.

Schemes used

Stable strum generators In modern UMZCHs, a number of typical circuits are widely used: differential cascade (DC), struma booster ("struma mirror"), equalizer circuit, cascode (with successive and parallel circuits, the others are also called "la" we beckon with a cascode"), a stable generator struma (GST) and others. Their correct curing allows you to significantly improve the technical characteristics of the UMZCH.

The assessment of the parameters of the main GTS circuits (Fig. 62 - 6 6) is carried out using additional modeling.

The author's mark was to emphasize the tension, which was added to the sound of "space" at the hour of the front entrances, and discos.

Of course, I wanted it to fit in a case of relatively small dimensions and be easily transported.

Another advantage is the availability of components.
When I reached the Hi-Fi level, I chose a complementary-symmetrical output cascade circuit.

The maximum output voltage of the booster was set at 300 W (at 4 ohms). With such pressure, the output voltage becomes approximately 35 V. Also, for the UMZCH, a bipolar voltage is required in the range of 2x60 V. The power supply diagram is shown in Fig. 1 . The UMZCH has an asymmetrical entrance. The input cascade is created by two differential boosters.

A. PETROV, Radiomir, 201 1, No. 4 - 12

So, now let’s try to create a sound enhancer that simply works.

To get a thorough understanding of sound technology, you have to gradually master a wealth of theoretical material and not forget to gain a wealth of knowledge from the world. Perhaps it will be easier to acquire wisdom if you move and move like you work in a warehouse.

This article also cannot do without a theory - in that it is necessary to know the basics and what can be explained without formulas and graphs. In the meantime, it will be enough to use the multitester.

Note:

If you have not soldered electronics before, ensure that the components do not overheat!
Soldering iron - up to 40 W (more than 25 W), maximum permissible hour of soldering without interruption - 10 s.
The soldering joints for heat dissipation are placed 0.5-3 cm from the soldering area on the side of the body using medical tweezers.
Acids and in. Active fluxes cannot be frozen!
Solder POS-61.
Zliva in Fig.
- The simplest UMZCH, “who just works.”

This can be obtained both on germanium and silicon transistors.

To get a thorough understanding of sound technology, you have to gradually master a wealth of theoretical material and not forget to gain a wealth of knowledge from the world. components that require selection for a well-designed layout in the layout are indicated on the diagrams with either an asterisk (*) or an apostrophe (').

At the center of the same figure.- A simple UMZCH on transistors, which already develops a voltage of up to 4-6 W at an input of 4 ohms.

I want to do it the same way as before, in the so-called. class AB1, not intended for Hi-Fi sound, but if you replace it with a pair of these boosters class D (div. further) in cheap Chinese computer speakers, their sound will noticeably improve.

Here we learn about another trick: hard output transistors need to be placed on radiators.

To get a thorough understanding of sound technology, you have to gradually master a wealth of theoretical material and not forget to gain a wealth of knowledge from the world. Components that require additional cooling are outlined in dotted lines on the diagrams;

True, far from it;

Small

To get a thorough understanding of sound technology, you have to gradually master a wealth of theoretical material and not forget to gain a wealth of knowledge from the world.– another option is to use a pressing UMZCH (30 W, and with a live voltage of 35 V – 60 W) on pressing field-effect transistors:

The sound of the new one is already drawn to the highest level of Hi-Fi (as, obviously, the UMZCH works on the corresponding acoustic systems, speakers).

Tight flooring does not require great effort to get out of the way, so there is no pre-tension cascade. Even tighter field-effect transistors do not burn out the speakers due to regular malfunctions - they themselves burn out faster. It’s still unacceptable, but it’s still cheaper, but it doesn’t change the way to the bass head of the Guchnomovtsya (PP).

Balancing and maintenance of this UMZCH is not required.

UMZCH Gumeli circuits and specifications before them are given in the illustration.

Radiators of output transistors - 250 sq.

To get a thorough understanding of sound technology, you have to gradually master a wealth of theoretical material and not forget to gain a wealth of knowledge from the world. div. for UMZCH for fig.

1 room 150 sq.

div. for the option per fig.
3 (numbering is original).
Transistors of the forward cascade (KT814/KT815) are installed on radiators bent from aluminum plates 75x35 mm with a thickness of 3 mm.

Replacing KT814/KT815 with KT626/KT961 is not a good idea, the sound will not improve significantly, but it is seriously impossible to improve it.

This UMZCH is very critical in terms of electrical life, installation topology and wiring, so it is necessary to improve it for a structurally complete appearance and without the standard power supply.

The audio wire is a mystery.

The necessity of their consolidation is beyond doubt.

Between copper and domestic acidity, a very fine mixture of oxide is created on the faces of crystallites in the metal.

Metal oxides are conductors, since the strum of the dart is weak without permanent storage, its form is created.

Behind the idea, the creation of myriads of crystallites is responsible for compensating one for the other, but a little (apparently due to quantum inconsistencies) is lost.

It is enough to be marked by powerful listeners for the purest sound of today's UMZCH.

Distillers and traders shamelessly recommend replacing acid-free primary electrical copper - it is impossible to separate one at a time.

As a matter of fact, having already mastered sound technology, we came across the concepts of Hi-Fi (High Fidelity), high fidelity to sound.

There are different ranks of Hi-Fi, which are ranked as follows.
main parameters:
Smoothies of created frequencies.
Dynamic range - the ratio in decibels (dB) of the maximum (peak) output pressure to the level of atmospheric noise.
Let's compare the noise levels in dB.

To get a thorough understanding of sound technology, you have to gradually master a wealth of theoretical material and not forget to gain a wealth of knowledge from the world. The coefficient of nonlinear stress (KNI) on the nominal (satisfactory) output force.

LPC at peak tension is taken at 1% or 2% according to the vibrating technique.

Unevenness of the amplitude-frequency response (AFC) of a smoothie of operating frequencies.

For speakers - okremo at low (LF, 20-300 Hz), middle (MF, 300-5000 Hz) and high (HF, 5000-20,000 Hz) sound frequencies.

The ratio of absolute values of any value I (dB) is calculated as P(dB) = 20lg(I1/I2).

90 dB is equal to the volume of a symphony orchestra in a loud concert hall.

110 dB can be seen in an expanded orchestra in a hall with unique acoustics, of which there are no more than 10 in the world, but at the same time there is confusion: the louder sounds are perceived as marked by the willpower, or the annoying noise.

The noise zone in residential areas of 20-110 dB is the zone of extreme sensitivity, and 40-90 dB is the zone of extreme sensitivity, in which unprepared and under-informed ears fully perceive sensory sound.

It is clear that no one has it.
Pushing
The adjustment of the intensity of the equipment for a given intensity in the listening area is not the main and most important thing for electroacoustics.
For yourself, it is better to go with acoustic systems (AS): understand their tension using a simple method, and accept the nominal (matched) pressure of the UMZ equal peak (musical) speaker.
If the UMZCH does not clearly deliver its results to such speakers, the stink is mainly due to nonlinearity in the sound path.
However, the operation of the UMZCH has happened in recent years: the level of high-volume noise may be higher than the sensitivity threshold, because
It is important to determine the level of voltage output to the maximum tension signal.
Since it is quite simple to understand, then for a room in an ordinary apartment or a cabin and speakers with normal sensitivity (sound output) you can take the following.

UMZCH optimal tension values:

Up to 8 sq.

m – 15-20 W.
8-12 sq.
m - 20-30 W.

12-26 sq.

m – 30-50 W.

Non-linear solutions (NI) of the UMZCH - the difference in the spectrum of the output signal, which was not present in the input signal.

Theoretically, it is best to “sew up” under the level of loud noises, but technically it is important to implement it.

We really take it to your respects.

masking effect: at thickness levels lower than approx.

At this time of crisis in the growth of transistor technology, it is important to successfully capture sub-frequencies and side frequencies at the output of a good UMZCH using special damping methods.

To get a thorough understanding of sound technology, you have to gradually master a wealth of theoretical material and not forget to gain a wealth of knowledge from the world. And tube circuitry can be taken into account, which has become a mystery.

Whatever the basis may be, why can’t electronics be there?

Here the analogy with photography will be pre-river.

No one can notice that today’s digital SLR produces a picture that is much clearer, more detailed, with a wider range of brightness and color, and a lower plywood screen with an accordion.

I don’t want to turn Nikon “clicks photos” like “my fat gut got drunk like a bastard and I’m sleeping with my paws outstretched,” but I want Smina-8M to take a photo in front of which people will flock to the prestigious exhibition.

It's a shame if you can't get by without lamps.

Apparently, the electric guitar became a full-fledged salting instrument after the signal from the pickup began to be passed through a special attachment - a fuser - which directly creates its spectrum.

Without it, the sound of the string would be even sharper and shorter, because

The electromagnetic pickup reacts only to the modes of mechanical vibrations near the surface of the instrument’s deck.

Suddenly an unpleasant situation appeared: the sound of an electric guitar with a fuser arouses greater strength and brightness at great depths.

This is especially true for guitars with a humbucker type pickup, which gives an “angry” sound.

Let's turn around to the end.

In a number of foreign devices, this circuit is widely known, but it is identical to it, except for the capacity of electrolytic capacitors, which appears in Radyansky’s “Radioamator Advice”, published in 1966. Tovstezna book with 1060 sides.

There was no Internet or databases on disks.

There, right-handed in the figure, there is a brief but clear description of a few parts of this scheme.

Improved from the same dzherel given to the next.

For transformers that operate with magnetization, the optimal type of core is made of Shp (perforated) plates, pos.

1 in Fig.

To get a thorough understanding of sound technology, you have to gradually master a wealth of theoretical material and not forget to gain a wealth of knowledge from the world. A non-magnetic gap is created during core penetration and is therefore stable;

Its value is indicated on the passport on the plate or measured with a set of probes.

The cover of this transformer needs to be removed from the openings in the plates and clamps (div. Fig. on the right), because

"For complete happiness" the folding of the magnetic circuit is carried out in a row.
in order (obviously, the windings with ties and external insulation are already on the frame):
Prepare diluted acrylic varnish or, as usual, shellac;
The plates with bridges are lightly coated with varnish on one side and placed as quickly as possible, without suffocating too much, against the frame.
Place the first plate with the varnished side in the middle, step on it with the unvarnished side to the first varnished side, etc.;
If the frame is damaged, apply staples and tighten tightly with bolts;

After 1-3 minutes, if the varnish from the gaps might stick out, add more plates until the window is filled;

Repeat paragraphs.

2-4 until the steel is tightly stuffed;

More importantly, the TDA7261 produces sound no brighter, but louder, up to 25 W, because

To get a thorough understanding of sound technology, you have to gradually master a wealth of theoretical material and not forget to gain a wealth of knowledge from the world. The upper limit of the voltage has been increased to 25 V. The lower limit, 4.5 V, still allows you to supply 6 V onboard voltage, then.

The TDA7261 can be run practically in all modes, except for the 27 V air supply. With the help of additional attached components (connection, right-handed in the figure), the TDA7261 can be run in the muting mode and with the St-By (Stand By) function. what to translate UMZCH into mode of minimal energy consumption depending on the input signal for a full hour.

The cost is pennies, so for stereo you will need a pair of TDA7261 with radiators of 250 square meters.

div. for skin.

If you want to be boosted by the St-By function, be careful - it’s not good to have wider speakers with them at 66 dB.

A subwoofer, which can be called a “subwoofer” or, literally, a “booster”, produces frequencies up to 150-200 Hz, in which range the human ear has virtually no direct impact on sound.

In a speaker with a subwoofer, install a “sub-bass” speaker in a hotel room with an acoustic design, even if it is a subwoofer.

The subwoofer is placed, in principle, more conveniently, and the stereo effect is ensured by the adjacent mid-high frequency channels and their small-sized speakers, until the acoustic design of any particularly serious ones can be avoided.

It is common knowledge that it is better to listen to a stereo with a full range of channels, rather than a subwoofer system, it is important to save money by investing in the bass path and making it easier to place acoustics in small spaces, which is why they are gaining popularity among achіv with basic hearing and not particularly powerful.

To avoid phase and transient problems, a booster for the subwoofer will be used.

To get a thorough understanding of sound technology, you have to gradually master a wealth of theoretical material and not forget to gain a wealth of knowledge from the world. Brooks: turn on the outputs of 2 identical UMZCHs simultaneously through the speaker;

input signals are sent to the antiphase.

The presence of phase and transitional problems in the Brookian is due to the constant electrical symmetry of the output signal paths.

The identity of the boosters that form the shoulders of the bridge is ensured by the installation of paired UMZCHs on the IMS, mounted on the same chip;

This, perhaps, is a single failure, if the power supply on microcircuits is reduced to discrete.

It is difficult to use a headphone booster with your own hands for two reasons.

Persha is a rumor “on the go”, that is.

Stay at home, unless the pressure on the audio output of the player or smartphone is enough to disengage the “gudziki” or “burdocks”.

The transistors of the output cascade of the power-assisted audio frequency (UMZCH) (most importantly, the storage etheric repeater, as in Fig. 1) heat up during the hour of operation, the voltage of the ether-base transistors and the working point of the cascade changes u.

Rotated to the optimal operating point, at which minimal disturbances are generated, a reversible circuit is used to change the displacement voltage U in the position of the temperature sensors installed on the atori.

The bias voltage can accurately adjust the temperature of the p-n junction of two or more output transistors.

Often this is not done accurately enough, and also with great delays, since the constant hour of the lantzug: p-n junction - transistor body - radiator - temperature sensor can reach several tens of seconds!

Also, the diagram of the task is shown in Fig. 2.

The input signal is divided into positive and negative pressure with the help of splitting on the diodes VD1 and VD2, then the necessary displacement flow (calm) I displacement is added to the skin pressure.

So, let’s look at a possible option for using a thermostable booster with deep environmental protection along the stream (for example, Strength X) in Fig. 3.

This actually comes from the support circuit ITUN (tension-ceramed struma).

The voltages at points A and B (before point C) are equal to each other and more precisely, the greater the coefficient of reinforcement of the booster OU1, therefore, according to the theory of booster with the gate coupling, everything is not stability in the middle of the points, surrounded by this connection, (and this transfer coefficient and voltage breakdown at the p-n junctions of transistors due to their temperature instability), has little impact on the accuracy of the output voltage!

Thus, if a positive voltage with displacements is applied to the input of such a booster, the output stream and displacement (quiet) are determined at the output, regardless of the temperature and parameters of the booster element. - what is thermal stabilization of the operating point.

When the input boost voltage from the strum output behind the circuit in Fig. 7 is different, for the “correct” operation of the diodes, the voltage that closes is required to be no less than 250 mV.

In order to create something, the currents through the diodes VD1-VD3 and VD2-VD4 will increase half of the constant flow of the output transistors of the voltage booster VT1 and VT2, and we don’t need anything.

The short-circuit voltage is removed with the help of the stable voltage voltage Vdisplace - R4-R5 (R7-R6).

In order for this displacement to “not matter” to the robot OU1 (OU2), it is necessary to supply the same voltage to the auxiliary circuit breaker R8-R10 (R9-R11) at its negative input.

The voltage booster follows the classic scheme: differential cascade (VT1, VT2), cascade with OB (VT6), vantage on the strum mirror (VT4, VT5), then cascade OK (VT9) and OB (VT8).

The circuit is insensitive to pulsating voltage.

It works miraculously against unstabilized voltages from +/- 20 V to +/- 60 V. The amplitude of the output voltage is less than the operating voltage by only 3.5 V. For example, with an operating voltage of +/- 45 V, the output voltage is 80 /140 W at Vantage 8/4 Ohm.

It’s also good that the circuit is upgraded from the standard “classical” circuit with thermal compensation with only a small middle part - from diodes VD4-VD7 to transistors VT18-VT19, which means it can be quite difficult to processing of a large number of ready-made boosters from different temperature sensors and improved reliability and sound quality.

In Fig. 11, there is another version of the booster circuit, which is simpler and more economical, but will provide the same booster parameters as the previous version.

The circuit in Fig. 10 operates with field-effect output transistors, but to recharge the high gate capacity of high-pressure transistors of the IRFP240 - IRFP9240 type, a heavy-duty emitter repeater is required, below VT18, VT19.

The modified circuit is presented in Fig. 12 and is called universal, since field-effect transistors have the same parameters as bipolar ones, only the output voltage rise is a little less (50 V/μS), which, however, is entirely sufficient for UMZCH " with high creativity.

Here, after switching on transistors VT9...VT14, the offending signal is sent to thermostable boosters VT15 - VT22.

For such boosters, it is important to adjust the balance of the streams through transistors VT16, VT20 and VT17, VT21, so as to equalize the input voltage of the booster (on resistors R19 and R20) and the output voltages on the emitter them resistors of the output transistors.

The ideal option, of course, is to use pairs of narrow transistors with close h21 and Vbe, such as KR159NT1 and KTS3103; and transistors from the same batch i).

The quiet and minimal currents of the output transistors are installed behind additional auxiliary resistors R13 and R18, R21 in parallel.

The circuit is the same for field-field and bipolar transistors!

(Connections of bipolar transistors are shown in Fig. 15).

The real scheme with the strum splitter according to Fig. 19 is shown in Fig. 22

The output voltage is only 1-1.5 V less than the living voltage!

The output voltage increase is 100 V/µS at 600 kHz smoothness (without input filter R1-C2).

The output reference is less than 5 mOhm.

Trimming the signal 300 NS.

The booster vibrates the output voltage for the sine and meander with a frequency of 150 kHz!, and also does not burn during a short circuit when only one life voltage is supplied!

The streams are calm and at least 30/120 mA are stored in the splitter itself (resistors R18, R19, R22, R23), but for their implementation it is necessary to install zero (cob) streams of the output boosters ITUN for additional resistors R25 and R34.

All descriptions can be re-adjusted, for example, to work in modes A, B or AB, and with stabilization of the selected mode.

I respect that minimal problems in the UMZCH can be removed in mode A, so you can show that the difference between modes A and super-A appears only at frequencies of 18-20 kHz and only in the thousands There are hundreds of them, which we can’t hardly absolute pitch!

Douglas Self, in the fifth edition of the book "Circuit design of increased tension. Dovidnik. (2009)" writes, back in 1975, having traced the super-A mode (the author called it the Peter Blomley method), but knew the actions of "artifacts in ci crossover " And having assessed this "as having no commercial prospects", which seems unfair.

The booster schemes outlined in this article work miraculously and ensure that the daily boosters need to work only in the super-A class without headaches about the place of installing thermal sensors and their dynamics ї robots".

I would like to continue the development of ideas that will achieve high results during the preparation of high-acid complexes of different levels of foldability.

I start not with their electrical characteristics, but with the design and design.

On the author of the author, to Radіo-Okomplek, Krim Pіdsilyuvalno-Mutatsky, I guilty to enter the EPU, the cassette magnetophon-output of the main parameters, the stimulation of the Sums of the Summary, the acoustic characteristics of the Gukovomovtsyv.

Thesis: Guchnomovtsi are the most important component of the radio complex, and are unlikely to require special explanation.

You can talk about the brightness of any channel of the sound creation tract, about the infusion of its parameters into the brightness of sound creation, or electroacoustic, because you can’t convert electrical signals into sounds in the singing frequency range with a pleasant result If there is a problem, then there is no swelling of other nodes in the tract, as a rule, will not lead to a proportional reduction in sound.

Naturally, the damping stage of the UMZCH output support can easily reach the level of the creation, but only until it reaches the limit value for this electroacoustic transformation.

Practically the same possible frequency characteristics should be presented to the other for the significance of the radio complex - UMZCH: the optimal frequency range for this can be 20-20000 Hz (with a drop in frequency response at the edges of no more than - 3 dB).

We do not rely on the harmonic coefficient, which can reach 0.5-1%, since the nonlinearity of the amplitude characteristics of the UMZCH did not lead to the appearance of inharmonious warehouses in the spectrum of the signal, which will increase, called non-thermal dulation problems.

The stench itself, and not the harmonious warehouses, is the source of unpleasant sounds.

Obviously, when assigning output voltage, intermodulation problems are to blame for the noise level of the UMZCH.

However, it is only possible to suppress intermodulation interference at a level of -70 dB (0.03%) in the presence of the main signal of a great level only if there is a spectrum analyzer with a dynamic range of at least 80 dB.

Unfortunately, such devices are practically inaccessible to most radio amators.

Indirectly, the magnitude of intermodulation problems can be judged by the harmonic coefficient, and this parameter at about -70 dB is also practically insignificant: a clear suppression of nonlinear problems among the available rads I don't care about the amateur.

Before objective methods for assessing the power of UMZCH, as well as any radio-electronic device, it is necessary to carry out an examination of circuit design solutions.

Of course, such an assessment requires basic knowledge of radio electronics and is beyond the power of radio listeners without radio engineering training; however, it is entirely accessible to radio amators with advanced circuit design There is another supporter behind the technique, which is illustrated below.

First of all, we need to pay attention to the output stage of the UMZCH.

Apparently, it is important to achieve a pleasant level of non-linear pain in the exercisers who work in the regime, with little effort.

It is also clear that mode A in the UMZCH leads to an unacceptable reduction in the efficiency factor and the corresponding design costs for heat transfer from the output transistors.

The intermediate mode AB also has important shortcomings: it is important to select the mode of transistors in the output stage and temperature stabilization of its output stage.

In this way, the front booster components are based on differential cascades in combination with alternating repeaters.

The advantage of the first ones is that the linearity is significantly more equal with the OE cascade (to remove the harmonic coefficient, which is more than 1%, it is enough to apply a voltage of 1 mV to the input of the OE cascade, so that the differential cascade introduces such disturbances equal, 18 times larger), others – 100% - on the OOS along the stream, which corrects the confusion, and the low output support, which changes the guidance.

He completely divided the power path of the radio complex.

On the one hand, the nominal input voltage of the UMZCH is responsible for guaranteeing the absence of background noise, and on the other hand, it is not necessary to interfere with the signal in the front boosters through the input іків folding signal to the boundary area.

The principle diagram of this booster (on the hard parts) is shown in Fig.

1. This is the first cascade of connections on op-amp DA1, connected simultaneously with transistors VT1 and VT2 in such a way that, first of all, increase the voltage rise at the output of the booster, and in another way, ensure the nominal voltage of the op-amp.

The front-end cascade (VT3 and VT4) operates in mode A, the output cascade (VT5 and VT6) - in mode B. The diodes VD1 and VD2 guarantee the presence of a calm output stage when changing the source through transistors VT3 and VT4 (for hunk their heating) in 1, 5-2 times.

A possible version of a wooden board is shown in Fig.

2. It is insured for the installation of MLT resistors and KM capacitors (the meaning of the elements depicted by dashed lines will be discussed below).

The coil L1 is wound in two balls (9+7 turns) with a PEV-2 dart, 0.8 on a mandrel with a diameter of 7 mm and for rigidity it is infiltrated with “Moment-1” glue.

Descriptions of the UMZCH do not protect against short circuits in the voltage and do not interfere with devices that are protected by Guchnomovts during the test of one of the transistors.

In the opinion of the author, these functions are completely different from calibrated melts.

Circuit design solutions, set in boosters, guarantee the presence of clattering in the Guchnomovets when the life is turned on and off.

Actions from the names of the op amps require balancing or inclusion of the corrective lancet.

At this point, the other board (Fig. 2) has a transfer opening for installing balancing resistors R15, RI6 (their total support is approximately 10 kOhm) and a core capacitor C13.

The dry conductor, before soldering the resistors R15, R16, is connected to the corresponding outputs of the op-amp.

If the op amp K544UD2, K154UD1-U154UDZ is victorious at the input of the UMZCH, it is recommended to turn off the low-pass filter.

What is the sum of resistor R14 (10 kOhm) and capacitor C12 (150 pF).
At podsilyuvachi village.
Input and output potentials close to 0 cannot be used as transition oxide capacitors, including non-polar ones.
All oxide capacitors are driven by a polarizing voltage that is 410 times the amplitude of the applied alternating voltage.
Unfair use of the mind reduces the reliability of the patient and can lead to additional pain.
All transistors through which the signal passes through the booster tract must be high-frequency, and low-noise at the input stages.
In the case of tension, it is necessary to assemble the transistors with a metal casing, so as to ensure good heat dissipation with the original design of the metal-plastic casings.
Vikorystovuvan literature:
Lexini Valentin and Victor.
About the importance of non-linear pain intensifying tension. - Radio, 1984, No. 2, p.
33-35.
Sontsiv Yu, High-grade stress booster.-Radio, 1984 No. 5, p.
29-34
Lexini Valentin and Victor.

Pre-corrector with rumble filter, - Radio.

1983 No. 7, p.

48-50.

News from:

THE TRUTH and "KAZKS" ABOUT HIGH ACIDITY SOUND CREATION

I. SUKHOV, m. Kiev, Ukraine

Long-standing developments of N. E. Sukhov (dynamic magnetization systems, high-fidelity UMZCH, etc.) have not yet been forgotten by lovers of high-fidelity sound recording.

These are shown both from editorial pages of the "Radio" magazine and from articles published in other publications, which, as far as we know, are the author's special post.

From the course of physics it is clear that any metal-to-metal contact (obviously, a thin oxide melt) can be seen as a nonlinear element of an electric stake.

And this non-linearity tends to distort the sound of high-fidelity systems.

However, for example, it is important to believe that V. Zuev feels the real robot of the UMZCH V and is more familiar with its circuit, since the power supply itself has eliminated the nonlinearity of the connecting wires and socket contacts Special respect was given to the relay during the development of this booster .

Zokrem, before boosting, a special cascade has been introduced that compensates not only for nonlinearity, but also for the active and reactive storage of the distributed support of the connecting wires, and the lance of the external OOS has been configured so that it compensates for nonlinearity "cold" contacts of the commutation relay to the output of the UMZCH and sockets.

In his work before “Radio” M. Klimenko also highlighted the “philosophy” that I followed when developing the UMZCH VV and conducting expert auditions.

So the axis, this reinforcement, was divided as the end link of the stand for subjective examination of the sound of CD players in one of the testing laboratories.

But then it turned out (I took the part as a “listener” from most subjective experiences) that the CD that was being played sounded through the monitor (studio speaker), which was connected to the UMZCH with different cables, in different ways!

Then, having thoroughly investigated the phenomenon, we realized that thousands of times hundreds of problems, such as giving UMZCH, nothing in comparison with the problems created by connecting cables with connectors.

Replacing the roses with gold plated ones, and the original connecting rods with a special one with a “non-crystalline” structure ($250 per pair twisted 4 m long), often solved the problem - the solutions changed many times, but not znikli.

So, after some experiments with Kenwood studio boosters with the “Sigma Drive” system, we tried to introduce cascades into the UM34 to compensate for the high impedance of the wires and the nonlinearity of the “cold” contacts.

In support of the subjective leveling of the sound of UMZCH B, I want to point out that I know only “anonymous” tests that are carried out under the so-called A-B-X examination system, in the course of both devices A and B, so far worry, invisible to experts and they are interrupted in a casual manner (say, “A”, then “B”, and the next interruption “X” is not voiced).

So the axis, during the A-B-X examination, the leveling of the UMZCH B B will be shortened or not subject to obvious testing in the authorized testing laboratories Kenwood KA-500, Quad 405, Yarn aha A-1 grade category $400 - 1000 and much more beautiful than the Brig , "Odyssey-010" or tube "Surf".

Before the speech, the A-B-X examination allowed us to reconcile how many High End experts have tried to distinguish the components of the Hi-Fin High End classes, as the only object of their boundless, or “blind” I went behind the black partition.

I, of course, do not have a perfect ear for music, but, in my opinion, a lot of the reason that “spin” around the word “High End” is similar to a religious dispute (“I believe it - I don’t believe it”), and the excitement is intensified individually method - to stimulate the mind.

The connection with this is due to the release by the Nakamichi company of a “special version” of the popular tape recorder “Nakamichi 1000ZXL”, in which all the details, right down to the radiators of the living unit, were gold-plated!

Try to individually increase the output support of any “average” transistor UMZCH to 2...4 Ohms (for which you need to connect a 10-20-watt resistor with such a support in series with the acoustic system) and do not exceed a quarter of its nominal voltage and for short-hour peaks the signal was cut off.

You realize that the sound in 95% of cases is “tube soft”.

The reason lies in the fact that many (but not all!) hummocks ensure a minimum of intermodulation noise (behind the sound pressure) not when the output support of the UMZCH is close to zero, but when its value is not less than 3...5 Ohm*.

However, such a support destroys the linearity of the frequency response and phase response of passive sectional filters of acoustic systems, which are designed for a zero value of the output support of the UMZCH.

Well, this is not a problem with speakers, but with acoustic systems!

Acoustics themselves bear special attention when developing systems, not only about the linearity of the frequency response and phase response of the sound pressure on a sinusoidal signal, but also about the minimization of acoustic intermodulation effects at REtK = 0 or else. Or better yet, standardize REbK, say, to a value of 3 ohms and provide separate such supports dzherela.

While in analog recording the third and fifth harmonics are more important in the spectrum, the digital ones on the right are much worse - without any combinations with excesses they do not create a harmonic series that is suitable for hearing, and their effect is This is noticeable even at levels close to 1%.

It’s easy to overshoot, when the signal level is about -50 dB and when the signals are met, the CD crosses the threshold of the permissible 1%.

At the bottom of this dynamic range there is no demarcation

quantization noise, and nonlinear interference.

And from the theoretical 97.8 dB, less than 50 dB is lost.

Sony is also subject to a subjective assessment of sound clarity carried out by the German magazine "Audio", as a result of which the MD rose from 45 points to 100 points after playing CDs (85 points ) and cassette recorder (85 points) and 3 -4th month of processing vinyl recorders (80 points) and DCC tape recorder (80 points), after 3-4 months, the digital audio compression system began to be fully developed, as a result of which in 4 days Lo people have selected (!) versions of the algorithm compression of ATRAC 1 -ATRAC 4, and the previous ones are not crazy with all the new ones (the “old” MD players do not create “new” recordings).

This is the time to figure out that in DCC and MD, like in CD, 16-bit quantization is used, and in order to reduce the data flow, it is written on the data carrier using a digital code based on algorithms such as PASC (Precision Adaptive Subband Coding) and A TRAC (Adaptive TRansforrn Acoustic Coding), which changes the digital data flow from 2 Mbit/s to 384 kbit/s and 300 to bit/s, then both DCC and M D are fundamentally less accurate in producing sound, lower CD.

The forecast is incorrect on the right, but for the sake of fairness, let’s guess the share of one more (theoretically, it will change for the accuracy of the CD) to the R-DAT format, which was at the time of its appearance in 1987. They also prophesied the place of decline K. Pokazovyy, whose sense is to get an accurate forecast from the author of these series, publications.

At that time, practically the entire foreign and domestic press wrote about those who before 1991. R-DAT will completely replace QC, perhaps in a single publication, in which R-DAT was introduced in a modest place in professional recording studios.

Finally, in return, due to the deep work of all correspondents and performers, whose moral, informational and material support made it possible to develop my rich designs.

* Div. Also the article by S. Ageev "What is the fault of the UMZCH mother's low output operation?"

at "Radio", 1EE7, No. 4, p.

14-16.

- Straight.
ed.

LITERATURE
-> 1. Sukhov N. High-fidelity UMZCH.
-> – Radio, 1 E8E, No. 6, p.
-> 55-57;
-> No. 7, p.
->
-> 57-61.
-> 2. Sukhov N. What is R-DAT.
-> Radio shorichny.
-> - M.: DTSAAF, 1E8E, p.
-> 1 65-176.
-> Section: [Low frequency boost (tubes)]
-> Save the article in:
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