The block of control of the audio-opid-siluvachem zі skhomovy regulator of the volume and du. Loudness regulators in lamp tubes

Miraculous solution for modding the subwoofer!

Е in reality

Cheap set

The purpose of the assignments for adjusting the density or other parameters of the audio system. It is a 2-channel digital changeable resistor 10 kOhm (AD8403, 255 cycles of regulation), which can be used for the help of a valcoder or an IC remote control. The IC remote control is not supplied with the kit.

Technical characteristics

additional information

The selection of the adjustable parameter is activated after the additional pressing, or the wrapping of the button of the encoder, IC-remote, the station is displayed on the LED1 ... LED20

The volume is adjusted using the additional buttons on the remote control VOL >,

The balance of the left-hand - right-hand is regulated by the help of remote control buttons |, | or the encoder, with which the lights LED17, LED18 and LED19, LED20 are alternately fired.

The forward-backward balance is regulated by the help of the remote control buttons TU-, TU+ or the encoder, with which the LED17, LED20 and LED18, LED19 lights alternately.

After the completion of 30 attachments, switch to the mode of regulation of density.

When pressing the MUTE button on the remote control, the number of channels changes smoothly, the LED17…LED20 lights start blinking. Press the MUTE button again or turn it again holiday camp thickness.

Dodatkovі nalashtuvannya vykonuyutsya for additional zamikannya vіdpovіdnyh vysnovki v rose JD1 (the first visnovka - square):

1-3 - throwing off all nalashtuvans (value for locking)

3-6 – mode of reassigning the remote control buttons (finishing the successive onslaught of change and increase in density, balance left and right, balance back and forward, MUTE)

1-4 / 1-5 - change the sensitivity of the rotary encoder and remote control

4-6 / 5-6 - increased sensitivity of the rotary encoder and remote control

All set parameters are stored in an independent memory of the annex.

Articles

Schemes

Sketch of connection

Contents of delivery

• Electronic resistor at the assembly - 1 pc. PCS.
• Instruction - 1 pc. PCS.

Food and drink

• Good day! Can you buy MP1231 Audio regulator 2 channel by delivery?
  • Good day, Andrey Petrovich! From the post of Russia, we can probably work out approximately in birch. For the time being, we have won delivery by the UPSR service.
• Where do you get the firmware?
  • Unfortunately, the firmware is not expandable.
• Is the remote control for the remote control included in the kit?

Zrobiv I podsilyuvach SE on the GU-50 and as a rule it became a power supply about the density regulator. I didn’t want to install a standard joint venture, it’s problematic to screw that remote control (remote control). It is expensive to buy a potentiometer from the APLS company, it is not available from our dealers.
Often bachiv at Merezhi schemes of regulators on resistive dilniks, among the people they are called "Nikitin's regulators".
Zreshtoy dіyshli hands try.

Attenuator circuit

I have verified the interim version from the crocodile 1.5 dB and the weakened 94.5 dB. Opir 10 kOhm for lamp podsiluvach cheated, pererahuvav 33 com. There are 6 steps with resistors of the next ratings.

On various sites that promote the designers of regulators, they write about the criticality of resistors, which are victorious in a dilnik. Recommend vikoristovuvati 0.5% row, at the extreme 1% drop. I have enough resistors, and I just selected the closest ones to the rozrahunkov ones, adding special respect to the symmetry between the channels. Butt: a resistor of 9.638 kOhm was needed for the rosettes, 9.653 and 9.654 were used (for 2 channels).

Up to the relay, there are no qualms hanging. I took a relay from an old mini PBX, a 24 volt Alcatel relay with 2 groups of contacts.
Well, just like that.

Functions of my block keruvannya

SU scheme

I wrote the program in assembler from scratch, without other people's lessons. I'll add a robot to do it is simple, depending on the voltage on the analog inputs (AN0, AN1), that is dependent on their values, including the necessary relays. At the same time, we hear the digital port GP3 ​​for the presence of a message from the IC remote control. On the output of GP2, data is inserted, and by ports GP4 and GP5 it is strobe into a pair of registers.
When changing a skin, write 2 bytes in sequence. Lanyards R25, C8, R28 filter the high-frequency overshoot when writing the register. An hour of recording is 192 µs.

Design and details BU

Relay module for inputs.

Drukovani pay vikonano technology LUT. On the board of the dilnik, the upper ball of foil is stripped like a screen.

In the design, it is possible to switch the relay to a different voltage by connecting it to another power block. Transistors can be replaced with analogous ones, or it is necessary to change that KT972 is a diode. IP23 registers can be series 155, 1533, 555, import 74S374 or if the payment is changed IP8 series 155 etc. The peculiarity of ІР23 is the high building of the venture.
I'm a victorist for the KRT-30 IC receiver. It is possible to win, whether it be other brands, smut, so that the modulation frequency of the remote control matches the receiving frequency, otherwise the distance of the remote control can be greatly reduced.

Living block you can revise in the appointed place. I have a black voltage of 15V stabilized at 12V, it is victorious for life to the display unit, and 24V is taken from the main UZCH transformer. The switch-on relay is switched on for 12V and it lives in the black power supply unit.

Okremo I’ll say about the life of the relay of the dilnik and the selector of the inputs: it can be well stabilized, so the relay is bigger high voltage go faster (less strums).

Changer of the input selector, outputs on the image diagram for the switch, it is also possible to change the resistor change (similar to the density regulator).

Regulator robot

Remote control available upcoming functions:
0 - enabled/disabled life
1 - thick [+]
2 - thick [-]
3 - switching inputs by ring [+]
4 - remikannya exits
5 - switching to the indicator mode
6 - switching inputs by ring [-]
7 - mute button
8 - switching off / switching off the anode
9 - do not win

Navchannya DU

In a partially connected extension, the thickness is shown at the maximum weakening, and the switch is at the 2/4 position (maximum).
Vmikaєmo attachment, for 3 seconds you need to press on the button of the remote control panel.
As soon as the remote control comes up, then H0 is displayed on the indicator - it is necessary to select the first key (from the list above), it is pressing.
The block accepts a code, H1 is displayed on the indicators, etc. The number is the number of the function in the list. Unnecessary functions can be filled with whatever buttons.

Just in 3 seconds after pressing the key on the remote control, they did not press it, otherwise the remote control did not follow the protocol, it would switch to the draft mode.

When you turn on the switch, the values ​​of the settings (settings, enter, exit) are taken from the position of the handles on the front panel.
When programming, you can boldly press on the buttons for 1 second or more (repeat is not processed).
Behind the bajan, vvazhayuchi by the programmer of data of the energy-independent memory of the controller, it is necessary to code the keys - two older bits to the code will be added.

Forgiveness option

Results

Filey

Organization density regulation at high-yield equipment, the bula was important for food and we will not forgive. The potentiometer, which is victorious for this, is to blame for the high quality of the channels (for paired potentiometers), good wear resistance, third-party sounds(shurkhіt i trіskіv) during regulation. Today, to change the most important changeable resistors, there are gallet jumpers, circuits on the relay or integrated microcircuits. For the essence of variety and complexity, such variants, violating one problem, give rise to others. That's why there are a lot of lovers sour sound dosi give priority to "old-fashioned" potentiometers.

Asking the method to know the yakіsny potentiometer for your pіdsilyuvacha, vyob'yazkovo and dosit svydko use on the company's products ALPS. Definitely, their vicarious varieties are found in expensive devices and may have high characteristics for a reasonable price. ALPS release as a fixed, and motorized potentiometer. The rest itself allows you to regulate the density for help remote control panel. It would be better to connect the control scheme.

This article presents a diagram that allows remote control with motorized potentiometers ALPS, as well as switching five inputs for the support of a standard remote control, which works for the RC-5 protocol.

One microcircuit.

Crimium of the voltage stabilizer, the scheme to replace only one microcircuit - the ATmega microcontroller from Atmel, as it decodes signals to the RC-5 standard, forms signals to control the engine and signals to control the relay of the input switch.

Schematic diagram the outbuilding is presented on the little one:

increase per click

The scheme to file is simple and there is no need to explain the reports. We linger less on certain important moments.

Ports PD2-PD6 through the K3 socket can control the relay of the input switch of the front switch.

Open ports PC and PB connected in parallel with the expansion of the external stream. The stench itself is vicorated for turning by the potentiometer drive through the K1 rosette. The maximum stream of the ALPS documentation engine is 150 mA. The maximum stream port of the Atmel documentation microcontroller is close to 40 mA. Paralleling 6 outputs, we can take a control stream greater than 200 mA.

To indicate the wrapper of the engine, in parallel with it, the LED D1 is turned off. Here it is necessary to select a two-coloured light, and behind the color of the light, you will understand, in which light the engine turns. For bajannya yogo can be put on the front panel of the pidsiluvach.

It is possible to live the construction except for the type of transformer, which is connected to the K5 rosette. But with a constant tension in the block of life of the podsiluvach himself. In this case, the voltage is supplied to the board through the K4 socket, and elements B1 and C10-C13 can not be installed.

Construction.

On the little one there is a distribution of elements on other boards I will add:

The design is divided into two parts for the convenience of placement at the body of the substation. The motorized potentiometer itself is placed on one board. This board is fastened at the direct proximity to the front panel of the support.

On the other board, a living block is placed, a microcontroller and other elements will be attached. The charge was placed in the corps of the subsidiary and it was added to the sound lances and, if possible, closed to reduce the overrides.

The receiver of the IC-signal needs to be also placed on the front panel of the switch, connecting it to the board with a three-wire cable. In case of a great old plume, in order to turn off non-stable and pardoning spratsovuvan primach, it is necessary to duplicate capacitors C2 and C3, soldering them without a middle on the priymach's whiskers.

All the constructions are realized with roses, as if they are interconnected by trains with a large number of veins.

On the other board of the potentiometer, there are contacts for connecting the screen to the signal cable and the screen to the cable by the motor, which is required.

A photo of the finished structure is shown in the small picture:

increase per click

The signals of the transistor switches for controlling the relay of the input switch are taken from the K3 rosette. To switch inputs on the remote control, press the digital buttons 1...5. In this rank, you can freely choose the required input. To switch inputs sequentially on the remote control, the buttons switch channels up/down.

Important respect.

The author tried his own solution with a remote control for Philips devices. I realized that not leather booths can produce products of a different brand, so try to reconsider the sum of other remotes. The universal remote control EuroSky 8 turned under the hand (in the photo, right-handed black):

Tsey remote control nasty keruvav various outbuildings at the booth, even if yoga was programmed to work with audio devices, they were afraid of a pardon when using additional functions. It turned out that the controllers did not correctly comply with the RC-5 standard.

The editorial office of the Elector magazine was modernized software I will build this with the method of minimizing pardons for an hour of work with different consoles of different pickers. Testing with the Philips SBC RU 865 universal remote control showed a miracle robot. With others universal remotes DK is also not to blame for the problems.

If you have a tester for remote control panels, then you can check the validity of your remote control to the RC5 standard using the help provided below the table:

Here, for example, incorrect codes are presented, as if transmitting the "EuroSky 8" remote control. The right column has the correct command codes.

The article was prepared for the materials of the Elector magazine.

Away with creativity!
Editor-in-Chief of Radio Newspaper.

The motorized potentiometer is not a novelty for a long time, so now it is ready for sale. The price for a new one can be said “cosmic” and not for the swarm of rich radioamators, just for me! 🙂
The idea itself is more than cicava, even if such a sound can be a rich plus - no changes to the regulation are introduced into the sound, you can easily connect with the remote control, for remote control, attachments can be stuck in any place, replacing it with a great potentiometer!
Ale povz pluses and minuses - For a direct connection of a potentiometer with a shaft, only a short motor is needed, a gearbox is needed for a larger one! Under the hour of regulation, there will be a distinct sound of the motor, the motor needs to be turned.
However, with all the minuses of this type of regulator, it’s still rich, and I gave a rozpovim how I realized it!

It all started from the fact that I had accumulated a lot of different motors, small and powerful:

It was necessary to stick them here. on the computer. 🙂

You can’t connect the motor without a middle with a potentiometer; =)
For whom do I need a gearbox! But it’s important to prepare the reducer on your own, I didn’t have any materials ... Here I went with my fantasy ...
I went to the market-flea market, having bought a cheap inertial Chinese machine for 10 hryvnias, taking from it I would need a detail for me and trying to communicate with a potentiometer.

As you can see, the motor was “inflated” in the same place, standing inertial shaft, from there I removed the gear and pulled on the entire motor, it was such a simple design!
The first samples were miracles! The motor just turned the handle of the resistor, and then wrapped the vin її all the same, evenly ... Then I needed a control circuit, but nothing more about it ...
Then I cut with wire cutters not needed parts of the axis of such a gearbox and, for an additional file, grinded off one part of the “pid twist”:

The reinforcement was more expensive than the Chinese, the Chinese did not care about the materials for the axis))
Vlasne scho became a zreshtoy:

The rosemary was not big... I sealed the reducer on the piece of textolite with hot glue (a cool thing, to the point, it’s more corny according to the state), and simply soldered the potentiometer with the body to the textolite!
Then, taking care of the motor control circuit ... I needed an indication about the volume level, so it’s necessary to attach it to the middle of the body, it’s necessary to have the regulator in the right position, it wouldn’t be good at night to switch the switch on maximum density! 🙂

Viyshla axis such an axis shemka:

The option is obviously “Syria”, but in practice everything works, it’s not bad!
Let's briefly describe how VONO works:
Twelve-step indicator has been selected on the transistors, which serves two functions - the indicator of the level of the volume (if the key of the adjustment of the volume is not pressed) and the display will become of the volume for a couple of seconds after pressing the key of the volume, or else it will switch back to the mode!
The motor control circuit itself was selected on the “555” timer, which generates impulses for controlling the motor, the connection with the motor is connected to the auxiliary “H” bridge, selected on tight transistors (like I had such and vikoristovav, and if I had only TIP100 TIP106). Transistors in the bridge

Impulses are generated by the driver, but in order to vibrati into some kind of motor wrap, we need to close one of the pairs of transistors, supplying one to either of the inputs (L or R)! If at qi enter the letter of the ІЧ priymach, as for example, zі statti about the past “Pіdsilyuvacha z remote keruvannyam”, then the volume can be regulated by a remote control! I dodatkovo two buttons on the case, well, do not start the remote control! 🙂
It may be necessary to select an additional indicator for the input of the level indicator (LINE IN), so that on the mp3 player it was not possible to set the volume to the maximum to show the level, and the axis of the computer's output was to be corrected on the surface ...
Also on the diagram there is a bright baby, how the connection of the system is connected!
By choosing a scheme from scratch, then having done a little work to get everything done ... So looking at my “H” mist and all the attachment in a flash:

It’s scary, I don’t fight, then I work =))))
I am dead for the new paid fee, yaku vyklav on the forum ... I’ll tell you right away - I її DO NOT revise, having robbed our vidkuruch and in nіy can be pardoned! I will be vydyachny to the one who will distort її! 🙂

Regardless of the stingy looking attachment, it works even better, smoothly adjusting the volume, when you went to the remote control, it was already handy!
Well, finally, I’ll bring a video:
On the video, you can see that the volume is regulated sharply, through those that I connected the test switch (on TDA8563) directly through the potentiometer to the computer! When connected through the tone block, the regulation is much smoother!
On the video, the indicator will turn to high, I will close the “High” contact and the indication will switch to the level of the level, the connection of the lights will be restored, after a couple of seconds, if I release the contact, the indication will turn to the mode of showing the level of the signal (VU Meter). I turn on the power switch, I give a signal ... For testing, I asked for a parcel on the TDA8563 and the car speaker, which vibrated, turning everything over on the table! 🙂

Most often, in the cascades of regulators, in the density of high-pitched sound-making equipment, without intermediary, like regulators, change resistors, which allow you to step by step or smoothly change the strength of the signal. However, it is not uncommon in the tube subsidiaries of the woofer that there are also step-by-step regulators of the quality, vikonan on the constant resistors and jumpers.

The simplest and widest circuitry solutions for the density regulator of a tube ULF when choosing a smooth adjustment is the introduction of a potentiometer with a change in the coefficient of the voltage difference at the input lance, interstage lance or negative lance zvorotny zv'azku pіdsilyuvacha. The movement of the engine of this potentiometer is subject to direct adjustment of the density. With this control potentiometer, it is recommended to change the resistors with the so-called logarithmic characteristic (characteristic type B), so that it is safe to change the density of the input signal at different levels of the input signals.

The fineness regulator with smooth regulation behind the luggage can be replaced by a regulator with 3 steps of regulation. For the sake of sufficient work to replace the control element, then the replacement of the potentiometer will install the lanyard of successively lowered resistors, the number of these and the difference in ratings determines the range and the law of regulation.

When choosing a circuit for a loudness regulator, it should be forgotten that the human ear can be sensitive to signals of different frequencies and loudness. Truly a manifestation of the one who has changed the density of the newly created sound signal the listener develops a change in the timbre of the sound, as it manifests itself in a significantly greater change in the volume of the warehouse lower higher frequencies against midrange signals. Therefore, high-pitched sound-creating equipment will have finely-compensated loudness regulators, in which, with a change in loudness, it is necessary to add warehouse lower and higher frequencies to ensure equal loudness. Due to the increase in density, the necessary increase in warehouse boundary frequencies changes. The basis of thin-amped regulators in the density of sounds is formed by potentiometers with one or two inputs, to which RC-lances are connected.

Turn on the volume control to change the output level of the ULF signal with minimal effects. In the case of such a regulator, a change resistor is installed, which includes either at the input of the power supply, or between the front and end cascades. The replacement of the changeable resistor, as we have already indicated, can be changed and the steps of the regulator, switching on the basis of switching and resistor cassettes with a different support. The simplified and important schemes of the simplest regulators in the complexity are shown in fig. one.

Fig.1. Simplified principles of the scheme of regulators in accuracy

In order to save the overwhelming of the first lamp of the power supply with a large amplitude of the input signal, the circuit for connecting the loudness regulator is shown in fig. 1, a. In this way, the changeable resistor zastosovuetsya bezperedno like a front attachment. Since the maximum amplitude of the input signal is small, a changeable resistor of the density controller can be installed in the loop of the keruyuchoy grid of one of the upcoming subsonic stages, as shown in fig. 1b. The advantage of such a connection is the weakening of the influx of the current transitions, to the fact that the regulator is given a corre- sponding signal, which is even stronger to the necessary level.

Regulation of equal thickness in tube ULF You can also ask for additional special cascades, for which you can change the coolness of the characteristics of the lamp. The principle of such regulators is based on the density of the foundations on the fact that when there is a lamp with a great internal support in the base cascade, the strength of such a cascade will be proportional to the steepness of the characteristics (S). Therefore, when vikoristanni lamps with a change in the steepness of the characteristics of the change in the strength of the cascade, it is sufficient to move the working point to a plot with a greater magnitude of steepness. Changing the position of the working point and the specific strength coefficient can be changed different ways for example, changing the magnitude of the voltage shift or the voltage on the screen lamp. The simplified and important schemes of such regulators are shown in fig. 2.

Fig.2. Simplified important schemes of regulators in the accuracy of changing the coolness of the characteristics of the lamp

It is necessary to note that the loudness regulators are considered, in which the principle of changing the coolness of the characteristics of the lamp is victorious, they can stop only in the first ULF cascades for remarkably small amplitudes of the input signal (no more than 200 mV). At higher levels of the input signal, significant non-linear effects can be eliminated, causing the curvature of the dynamic characteristics.

To regulate the loudness in low-frequency lamp subs, regulators are often used to compensate for low frequencies for small equal input signals. A schematic diagram of one of these regulators is shown in fig. 3.

Fig.3. Principal diagram of the loudness regulator with low frequency compensation at low input signal levels

An input signal is sent to the input of the cascade from a fixed level low frequencies within the given range. This value is determined by the values ​​of the resistors R1, R2 and R3, which determine the input dilnik, as well as the value of the capacitance of the capacitor C2. From the exit of the regulator of the lancet of the lancet of the lamp's grid through the dilnik, the adjustments with the elements R7 and C2, there should be a signal of a turning signal. The greater is the rіven of the richness, the more is the greater and the turn of the tongue. The value of the support of the resistor R7 determines the weakening of the lower frequencies of the lancet of the turning link to the lower frequencies of the input lancet. In an ideal scenario, by selecting the support of the resistor R7, it was possible to ensure that the weakening of the lower frequencies in the loop of the winding link was completed to their peak at the input lane. In this case, the shape of the frequency response of the signal at the output stage will be close to linear. Pointed at fig. 3 denominations of the elements of the insurance of the vikoristannya of one of the triodes of the lamp 6N2P.

With a change in the density of the signal behind the auxiliary potentiometer R6, the value of the turning signal changes, however, there are too many fixations for the lower frequencies. As a result, the lower frequencies increase in the output signal. With small values ​​of the density, the turn is practically daily, and the characteristic of the cascade is determined only by the parameters of the lancet R1, R3 and Z2. When tsimu pіdёm lower frequencies maximum.

One of the shortcomings of this scheme is those that the triode is connected to the frequency regulator, so with a strong input signal, the wines can be overwhelmed. However, the signal from the input is fed to the grid of the ceramic lamp through a dilnik, which is wound at a frequency of 50 Hz, ensuring attenuation more lower by 4 times. After all given scheme can work without delay when the input signal is equal to 4-5 V. It is also necessary to note that the circuit is sensitive to the level of the filtering of the anode voltage, so the R8C5 filter is installed in the lamp anode lance.

When designing a tube ULF radioamator, it is not uncommon to set your own switching on to the cascade, with the help of which it is possible to regulate the volume remotely. Zastosuvannya in the primary regulators of wine remotes with potentiometers placed in them can hardly be taken into account in the distance, but most of the time, such remotes are connected with a power supply for additional cables, which are made before the appearance of these effects. However, there are various circuitry solutions that ensure the regulation of the density with a winder, for example, at the sight of a changing voltage fast strumu, for the practicality of the mind. The principle diagram of one of the options for the density controller with remote control is shown in fig. 4.

Fig.4. Principal diagram of the density regulator with remote control

The main feature of the regulator, which can be seen, is the inclusion of a replacement for the cathode resistor of the triode of the subsiluvial cascade of one more triode, which acts as a regulating element. When changing the value of the constant negative voltage, which is applied to the grid of another triode, the value of the support is changed. As a result, the depth of the negative return link for the first triode is changed. So, for example, at the time of growth of the internal support of another triode, the negative link grows, and the strength of the first triode decreases. In this scheme, the imported sub-triode of the ECC82 type can be replaced, for example, with a 6N1P lamp.

High-yield lamp sound-making equipment of wide width has thickness regulators with thin compensation. The need for such regulators to be loud is explained by the fact that the sensitivity of a person’s voice changes regularly depending on the frequency and the loudness of the sound signal that is received. So, for example, increasing the sensitivity to increase the frequency of warehouse mid-range frequencies in those of the warehouses of high and especially low frequencies. Therefore, with a change in the loudness of the listener, it becomes sub'jective that the ratio of the warehouse high and the lower frequencies in the vodvoryuvannogo range changes at once. As a result of the conduction, the next room was stored songs of fallow, who took away the name of crooked equalities.

Щоб при різних рівнях гучності всі частотні складові відтворюваного сигналу сприймалися однаково, у високоякісній звуковідтворювальній апаратурі застосовуються регулятори гучності, в яких при зменшенні гучності здійснюється необхідне піднесення складових нижчих та вищих частот, а зі збільшенням гучності підйом складових граничних частот зменшується. Such regulators are called thin-compensated or frequency-deposited. Obviously, retailers should work to the point that the characteristics of thin-amped regulators in thickness would be closer to the curves of even density.

Himself simple option induce a frequency-sparse loudness controller to combine a centrally-displaced loudness controller and a tone control with a variety of paired changeable resistors. The principle diagrams of such regulators of accuracy are shown in fig. 5, a that 5, b. Quite often, in thin-compensated thickness regulators, potentiometers are used with one or two inputs, to which RC-lances are connected. p align="justify"> 5, art.

Fig.5. Principles of simple thin-compensated regulators in thickness

The current compensation regulator can be multi-stage adjustable. Prior to such regulators, except for the capacity of the potentiometer of a different design, it is possible to choose a significantly wider range of regulation. The schematic diagram of one of the options for the ULF input lamp cascade with such a regulator is shown in fig. 6.

Fig.6. Principal diagram of a thin-compensated thickness regulator with three stages of regulation

Loudness in the thickness regulators can be implemented with the help of special filters. The principle diagram of the regulator with a thin-compensation filter is shown in fig. 7.

Fig.7. Principal scheme of the loudness regulator with a thin-compensation filter

In the scheme, the thin-compensation filter is a subducting T-bridge, the transmission coefficient of which for storage medium frequencies is lower in the range, lower transmission coefficient for storage low and high frequencies. In the maximum density mode, the motor of the potentiometer R4 is responsible for being in the top position of the circuit, with which the short circuit filter does not interfere with the shape of the frequency response. To change the density of the motor of the potentiometer R4, move it down, with which the shunting of the upper part of the potentiometer changes to the filter. As a result, warehouses of singing frequencies pass through the filter in a similar way to the next frequency response. Oskolki warehouses of medium frequencies are attenuated by the filter of the greater world, lower warehouses of extreme frequencies, changes in the frequency response of the substation are fluctuating, close to the curves of evenness. Potentiometer R4 is the mother's fault logarithmic characteristic(Type B).