NK2946-channel color music set-top box. Six-channel color music set-top box Color music 6
The device is designed to accompany a musical soundtrack with color effects on a six-channel (2 x 3) RGB tape.
Supplied as a board and a set of components, including a programmed microcontroller, for self-assembly of the device.
Input voltage: DC 9...24 V;
The current consumption depends on the load (power R G B LED strips);
Maximum collector current of each power transistor (TIP122): 5 A;
Quiescent current: 30 mA;
Number of output channels: 6 pcs.;
Overall dimensions of the printed circuit board: 67 x 53 mm.
Description of the scheme:
A 9-24 V DC power plug is connected to connector J1, in accordance with the selected RGB strip, LED D2 signals the power supply.
A 3.5mm Jack plug is connected to connector J2, which must be connected to any sound-reproducing device, or to the output of a low-frequency amplifier.
An LED is connected to outputs P1, P2 RGB tape 12 / 24 V, as shown in the diagrams, or match at your discretion
color channels (MF, LF, HF). Using the adjusted resistor R5, we set the level of the input sound signal, which will determine the brightness of the LED strip.
Button SW2 "Fadespeed" A single press changes the speed at which channels fade in the absence of a stronger peak.
Depending on the nature of the music, you may need different speed attenuation for better visual perception.
Holding the SW2 button for more than 3 seconds will switch the operating mode (standard, aggressive, aggressive x2).
SW1 Runlight button, a single press changes the mode of the device at rest (running lights, smooth backlight,
turned off). By default, when you first turn on the device, the running lights mode is set.
Holding the SW1 button for more than 3 seconds saves the current settings (fade speed, quiet behavior mode, operating mode).
Holding both the "Runlight" and "Fadespeed" buttons simultaneously for more than 3 seconds will reset to initial settings.
ATMega 8 microcontroller firmware update
Through the J3 (SPI) connector, without desoldering the ATMega 8 microcontroller, you can change the executive program, which can be downloaded from the website: http://lightportal.at.ua
By following the links: Catalog of articles / Color music installations / Lichtorgel - international color music.
There you will find various updates and source codes to change the program yourself.
For programming you can use
Are available
Buy in bulkThe light and music set-top box is equipped with microphones, which allows you to complement the music playback with bright colors without connecting to a sound source.
The greatest color effect is achieved by connecting multi-colored 220V incandescent lamps with a power of no more than 50W per channel to each of the six channels. Each channel has independent adjustment.
The device can be installed in a plastic case BOX M-54P; it is not included in the kit.
Specifications
Additional Information
Do you want to build a home lighting system with your own hands? The MK294 kit will help with this!
The easy-to-assemble board, housed in the supplied housing, allows you to control incandescent lamps with a total power of up to 300 W.
Lamp strings are connected using convenient screw connectors.
Each of the three frequency channels (low, medium and high frequencies) has two separately adjustable outputs, so the set-top box allows you to separately control six channels.
Powerful thyristors are used for control.
Using built-in microphones, the device responds to any sounds made in its vicinity. Trimmer resistors can be used to adjust the sensitivity of each channel in accordance with a specific noise and sound environment.
The console is reliable and will serve as a light and music device for home parties for a long time!
The device can be installed in a plastic case BOX M-54P; it is not included in the kit.
Articles
What is required for assembly
- Please study the RELATED PRODUCTS tab: this will help you make full use of the device's capabilities.
Assembly order
- All components included in the kit are mounted on printed circuit board by soldering method.
- All fixed resistors (except R30 and R31) are installed vertically on the board.
- Resistors R7, R8, R18, R19 are not installed on the board and are not included in the kit. If you are an experienced radio amateur, then, if necessary, you can install them to reduce the gain of the stages and, therefore, reduce the sensitivity of the device to the signal from microphones. The value of resistors R7, R8, R18, R19 is determined experimentally, by installing temporary trimming resistors with a nominal value of 100 kOhm.
- For device operation resistors R7, R8, R18, R19 are not needed and therefore they are not included in the device kit and are not installed on the printed circuit board.
Maintenance
- The device operates from a 220 V network! The board must be insulated so as to prevent it from touching live elements. The wires of the garlands must be well insulated and have no exposed areas.
Questions and answers
- The set-top box does not work, what could be the problem? On the 12 volt outputs, nothing changes from the sound =(
- This usually happens due to installation errors. Please send high-quality photos of the soldered printed circuit board on both sides. Let's look for the bug together. Address: [email protected]
- 500 watts for each channel out of 6? or for the entire installation?
- Typo. Up to 50W incandescent lamp per channel, up to 300 for the entire installation.
- I would like to see the color music scheme. At least one channel. It is not even known whether it is analog or digital, are there frequency filters, if so, what order? a lot of questions
- See https://site/zip/nk294.pdf
The color music set-top box is equipped with microphones, which allows you to supplement music playback with bright color accompaniment without connecting to the ULF output. The greatest color effect is achieved by connecting multi-colored incandescent lamps with a total power of no more than 500 W to each of the six channels. Each channel has independent adjustment.
NK294 Specifications| Parameter | Meaning |
| Upit. variable, V | ~210..240 |
| Upit. nom. variable, V | ~220 |
| Load on each channel without radiators | ...60 |
| Load on each channel with radiators | ...500 |
| Overall dimensions of the printed circuit board, LxWxH, mm | 85 x 58 |
| Overall dimensions of the case, LxWxH, mm | 91 x 64 x 32 |
| Recommended housing included | BOX-M54P |
| Operating temperature, °C | 0...+55 |
| Relative operating humidity, % | ...55 |
| Warranty period | 12 months |
| Package weight, g | 300 |
All components included in the kit are mounted on a printed circuit board using the soldering method.
All fixed resistors (except R30 and R31) are installed vertically on the board.
Resistors R7, R8, R18, R19 are not installed on the board and are not included in the kit.
If you are an experienced radio amateur, then, if necessary, you can install them to reduce the gain of the cascades and, therefore, reduce the sensitivity of the device to the signal from microphones. The value of resistors R7, R8, R18, R19 is determined experimentally, by installing temporary trimming resistors with a nominal value of 100 kOhm.
To operate the device, resistors R7, R8, R18, R19 are not needed and therefore they are not included in the device and are not installed on the printed circuit board.
ATTENTION! The device operates from a 220 V network!
The board must be insulated so as to prevent it from touching live elements. The wires of the garlands must be well insulated and have no exposed areas.
Electrical circuit diagram NK294
NK294 FAQ
When operating the NK294, the thyristors burned out after 4 hours. At the same time, a spark jumps between the legs of the thyristors. I replaced the thyristors with new ones, but they also burned out. What is the reason?
- Possible reason- thermal overheating of triacs C106D1. In the absence of radiators on triacs, the permissible load for each is no more than 60 W. Please reduce the load on each channel and check the operation of the device.
- NK294 does not work. What is the reason?
- Most common reason This is due to incorrectly installed elements on the printed circuit board, the pinout of which was confused by the user: electrolytic capacitors, diodes, transistors, even triacs manage to be installed incorrectly! Please, Double-check that each element is installed correctly and meets its nominal value.
You soldered the device yourself and encountered a certain problem. We are sure that There are no miracles, there are bad contacts and simple inattention. Troubleshooting always begins with an external inspection. In order to see the problematic contacts, please follow these steps:
Please make sure that:
- The elements on the board are installed according to their pinouts(usually they make mistakes in installing triacs).
- Resistor values correspond electrical diagram, For what check the resistance of each with a tester.
- The values of electrolytic capacitors correspond to the electrical diagram and they installed correctly according to their polarity.
- The ICs are installed according to the keys on their cases according to the photo below.
- Make sure there are no shorts (contacts) between adjacent tracks on the printed circuit board, to do this, thoroughly rinse the board with alcohol (medical, isopropyl, etc.) using a brush.
Place the soldered board in a bath of rubbing alcohol or isopropyl alcohol. Wait 30 minutes and then remove. Thoroughly clean the board with a brush. Now you can look at the quality of the soldering.
- Do you see any unsoldered tracks?
- Do you see short-circuited paths?
- Are you sure that the quality of your soldering is ideal?
If this is done, then check integrity of all connections on the board, for which, WITH A TESTER, CALL ABSOLUTELY ALL POINTS CONNECTED BY TRACKS on the board, and then:
- Solder the board again, fortunately there are few parts on it.
- Wash it again with medical or isopropyl alcohol.
Some users do not wash the boards and therefore troubleshooting is a problem for them.
The NK294 has two identical arms whose operation is identical. Let's look at the lower shoulder.
This arm has two stages for amplifying the signal from the microphone. First, let's determine the serviceability of the first amplification stage on VT2.
- Please disconnect ~220V from the device.
- Now you need to check the passage of the signal from the headphones to the control pin of the triac. This can be done using an oscilloscope or TON-2 headphones with a resistance of 1600 Ohms.
- Take TON-2 headphones with a resistance of 1600 Ohms. Remove the plug and volume control on their wire.
- Connect one headphone wire to the common wire of the circuit, and connect the second to the VT2 collector.
- Supply +12V power to the zener diode VD1.
- Turn on music near the device’s microphone. At the same time, a sound signal is heard in the headphones, which confirms the serviceability of the first amplification stage on VT2. Otherwise, please check the matching resistor values around transistor VT2.
- Connect one headphone wire to the common wire of the circuit, and connect the second to the VT4 collector.
- Turn on music near the device’s microphone. At the same time, a sound signal is heard in the headphones, which confirms the serviceability of the second amplification stage on VT4. Otherwise, please check the matching resistor values around transistor VT4.
- Connect one headphone wire to the common wire of the circuit, and connect the second to the control pin of VS2.
- Turn on the music near the device’s microphone and set the slider of the trimming resistor R25 to the uppermost position according to the diagram. At the same time, a sound signal is heard in the headphones, which confirms the serviceability of resistor R25. Otherwise, please check the polarity of electrolytic capacitor C13.
Likewise, please check the operation of the upper arm of the device.
“Color music installations (CMU) provide the accompaniment of musical works with light effects. Such devices improve the perception of musical works and significantly increase the degree of their emotional and psychological impact on the individual.
In the development of color music, two main directions can be distinguished.
The first assumes the absence of a strict connection between a piece of music and its color accompaniment. A necessary link in the process of transforming music into a color pattern is a “color operator” - a person with a musical education who performs the light part at the Central Music Center, guided either by the composer’s intentions or by purely emotional laws of analysis of a musical work. At the same time, automatic control of the color pattern is not excluded. Obviously, despite the high aesthetic richness of such an audiovisual program, a significant drawback of such systems is their great complexity and cost, as well as the need for a highly qualified operator.
The second, much more widespread direction, is represented by devices that automatically analyze a piece of music directly during its performance according to a predetermined algorithm that changes the light flux accordingly in terms of brightness and spectral composition. The advantage of this type is relatively simple design and, as a consequence, the ease of its implementation and mass repetition. However, in such settings the possibility of complete correspondence of the nature of the color accompaniment to the style and content of the musical work is excluded.
Recently, many models of central medical equipment have been created and are successfully operating using this principle - from powerful stationary installations for servicing cultural and entertainment events to small indoor ones designed for a limited audience. In most cases, DMU terminal devices reproduce the color pattern in a plane. When using incandescent lamps, it is practiced to place them in separate shades - according to the number of colors reproduced by the installation. This solution does not allow the full use of the capabilities of the CMU and reduces the effectiveness of its emotional impact on a person.
Most often, the CMU terminal device is a flat screen onto which a color pattern is projected using electric lamps with reflectors located behind it. In the best cases, you can observe the so-called color mixing effect on the screen, as a result of which the illusion of multicolor is created when using emitters of only three colors - red, green and blue. At the same time, the color pattern is distinguished by a somewhat greater variety and variability, while in the absence of the named effect, the listener gets the impression of monotony and repeatability of the color pattern. Consequently, the effectiveness of the color accompaniment of music largely depends on the placement of light sources in space and the properties of the screen itself.”
I specifically cited this extensive quote from the article here because, in more than 30 years since its publication, in principle, little has changed. The main improvements affected mainly the technical side of color music: analog-to-digital and digital-to-analog converters, computer control using specially developed programs, lasers and LEDs as light sources. Few people today can say that they have seen a color-musical work accompanied by a “color operator.” The vast majority of CMUs are automatic. Moreover, many people do not understand the very essence of color music at all and consider the blinking of multi-colored (or even single-color!) light bulbs more or less in time with the music to be color music. I want to dispel this misconception a little. My article is intended primarily for young people who know how to read and comprehend what they read. And it’s even better if they want and try to do something with their own hands.
2. “See” the sound...
Once upon a time, a long time ago, a radio broadcasting network was connected to all houses. So-called subscriber loudspeakers were connected to it, which reproduced one (later three) radio programs broadcast over the wire. The fee for this was a pittance, so such a loudspeaker “mumbled” constantly. The radio network voltage in our area was ~36 V at a very low current. I guessed to connect a flashlight light bulb to the radio broadcast line and suddenly discovered that the light bulb filament flickered in time with the sound. It was a revelation for me! It was the first time I saw that sound could be converted into light. The brightness of the light bulb changed according to the volume of the sound. Later, when I began to get involved in radio engineering and read all sorts of smart books, I learned two more things. First, the sound range consists of low (LF), medium (MF) and high frequency (HF) vibrations. This had nothing to do with color music, but followed from the possibility of adjusting the timbre (low frequency and high frequency) in the amplifiers of radios, electric players and tape recorders. Secondly, I learned that the Russian composer Alexander Scriabin, at the beginning of the twentieth century, decided to combine music and light and used the designation of “color” notes in the recording of some of his works. Of course, Scriabin did not even think about some kind of automatic light accompaniment for music. He meant that only a person can fully realize it. I have not seen Prometheus with lighting, but this opportunity literally amazed me.
The very idea of automatic color accompaniment of music had already been implemented (by the time I began to become interested in this), and simple schemes also already existed.
The simplest CMP works as follows: electrical signal audio frequency arrives at the separation filters --> each filter selects its own frequency band from the audio range: low, medium and high --> each signal goes to its own light bulb, the brightness of which changes in proportion to the level of the signal of the corresponding frequency (Fig. 1):
The division into frequency subranges is conditional, for example: LF - from 300 Hz and below, MF - from 300 to 2500 Hz, HF - from 2500 Hz and above. Frequency filters do not give sharp range boundaries because they partially overlap (Fig. 2), and this is precisely what allows you to obtain many color shades from the three primary colors (red, blue, green). 
The correspondence of frequency ranges to red, green and blue colors is also conditional. But there is logic in this: low frequencies of the audio range correspond to low frequencies of the light spectrum, medium - medium, high - high.
The number of DMP filters can be increased by dividing the audio range into b O a larger number of frequency channels, or, for example, assign each note a certain color of the solar spectrum (Fig. 3): 
Rice. 3.
However, I will not consider possible prospects for expanding the capabilities of the CMU and aspects of their design complexity.
I will tell you and, if possible, show you a few simple and not so simple designs of the CMP.
The simplest CMP(Fig. 4) is a 1:1 practical implementation of the block diagram shown in Fig. 1.
Sound signal from the speaker of the radio receiver, player, tape recorder goes to bandpass filters. Resistor R1 is used to adjust the signal level. HF filter – capacitor C1, MF filter – capacitor C2 and coil L1, LF filter – coil L2. 2.5 V or 3.5 V light bulbs, colored blue, green and red, are connected to the output of the filters. Capacitors - any constant capacity (except oxide ones). The bobbins are wound on metal bobbins from a sewing machine. The bobbins have an internal diameter of 6.5 mm, an external diameter of 21 mm, and a width of 8 mm. Coil L1 is wound on one bobbin and contains 400 turns of PEL 0.23. Coil L2 - on two bobbins, fastened with a metal bolt, contains 2x300 turns of the same wire.
This was my first DMP, which I connected to the output of the 5U06 amplifier for the KPSh-4 school film projector. The 3.5V light bulbs were painted with watercolors. The set-top box worked, the change in the brightness of the lamps in time with the changes in the bass, midrange and high-frequency sound signals was clearly noticeable. But due to the fact that primitive coloring did not give the effect of mixing colors, I did not design this CMP as a separate design.
3.1. A simple DMP with three transistors (Fig. 5) from the magazine “Young Technician”, 1975, No. 11 contains only three powerful transistors of the P213A type (others are also suitable, for example P4, P214-217). Transistors are included in amplification stages according to a common emitter circuit, and each of them is designed to amplify a very specific frequency band. So, the cascade on transistor VT1 amplifies the HF, on transistor VT2 – midrange, on transistor VT3 – LF. Frequency separation is carried out by simple filters made of RC chains. The input signal to the filters is supplied from the potentiometer R1, which in this case is a common gain control for all stages. In addition, to select the gain of each stage in the circuit there are variable resistors R3, R5, R7. The bias at the bases of the transistors is determined by the values of resistors R2, R4, R6. The load of each stage is two parallel-connected light bulbs (6.3 V x 0.28 A). The circuit is powered by a DC source with a voltage of 8-9 V, which is supplied from a half-wave rectifier on diode VD1. Capacitor C1 smoothes out the ripples of the rectified voltage. An alternating voltage of 6.3 V is removed from the “hot” winding of the power transformer of the device to which the set-top box is connected.
Setting up the set-top box comes down to selecting the values of resistors R2, R4, R6. In the absence of an input signal, their values are selected such that the filaments of the lamps barely glow.
I made this DMP as a separate structure in a rectangular case. Inside there was a board with all the details. Llamas (2 pieces 6.3Vx0.28A per channel) were fixed in front of the reflector (a piece of thick cardboard covered with foil). The screen was a flat piece of corrugated plexiglass. I painted the light bulbs with ballpoint pen paste dissolved in colorless nitro varnish. As a result, I got a multicolored color picture resulting from mixing colors.
In the ancient photograph (Fig. 6) the box on the right on the table is my transistor DMP.
3.2. CMP on four transistors (RADIO, 1990, No. 8) 
This DMP differs from the previous one in the presence of a pre-amplifier and its own power supply (Fig. 7), which allows it to be manufactured as a separate autonomous structure.
I believe that the diagram does not require any special explanation. It should be noted that it wanders on the Internet from site to site, and the output transistors are loaded not only with lamps, but also with LEDs and electric motors for the laser DMP.
3.3. DMP on 10 transistors with a background channel 
(http://shemabook.ru/)
Many, after making a simple color music console, will want to make a design that has a higher brightness of the lamps, sufficient to illuminate a screen of impressive size. The task is feasible if you use car lamps (12 V voltage) with a power of 4...6 W. An attachment works with such lamps, the diagram of which is shown in Fig. 8.
The input signal taken from the terminals of the dynamic head of the radio device is supplied to the matching transformer T2, the secondary winding of which is connected through capacitor C1 to the sensitivity regulator - variable resistor R1. In this case, capacitor C1 limits the range of the low-frequency set-top box so that it does not receive, say, an AC background signal (50 Hz).
From the sensitivity regulator engine, the signal goes further through capacitor C2 to the composite transistor VT1VT2. From the load of this transistor (resistor R3), the signal is supplied to three filters that “distribute” the signal among the channels. HF signals pass through capacitor C4, MF signals pass through filter C5R6C6R7, and LF signals pass through filter C7R9C8R10. At the output of each filter there is a variable resistor that allows you to set the desired gain of a given channel (R4 - for HF, R7 - for midrange, R10 - for LF). This is followed by a two-stage amplifier with a powerful output transistor loaded onto two series-connected lamps - they are colored for each channel in a different color: EL1 and EL2 - blue, EL3 and EL4 - green, EL5 and EL6 - red.
In addition, the set-top box has one more channel, assembled on transistors VT6, VTIO and loaded onto lamps EL7 and EL8. This is the so-called background channel. It is needed so that in the absence of an audio frequency signal at the input of the set-top box, the screen is slightly illuminated with neutral light, in this case purple.
There is no filter cell in the background channel, but there is a gain control - variable resistor R12. They set the brightness of the screen illumination. Through resistor R13, the background channel is connected to the output transistor of the midrange channel. As a rule, this channel works longer than others. While the channel is operating, transistor VT8 is open, and resistor R13 is connected to the common wire. There is practically no bias voltage at the base of the VT6 transistor. This transistor, as well as VT10, are closed, lamps EL7 and EL8 are extinguished.
As soon as the audio frequency signal at the input of the set-top box decreases or disappears completely, transistor VT8 closes, the voltage at its collector increases, resulting in a bias voltage at the base of transistor VT6. Transistors VT6 and VT10 open, and lamps EL7, EL8 light up. The degree of opening of the background channel transistors, which means the brightness of its lamps, depends on the bias voltage at the base of the VT6 transistor. And it, in turn, can be set with a variable resistor R12.
To power the set-top box, a half-wave rectifier based on diode VD1 is used. Since the output voltage ripple is significant, the SZ filter capacitor is taken with a relatively large capacity.
Transistors VT1-VT6 can be of the MP25, MP26 or other series, p-n-p structures, designed for a permissible voltage between the collector and emitter of at least 30 V and having the highest possible current transfer coefficient (but not less than 30). With the same transmission coefficient, powerful transistors VT7-VT10 should be used - they can be of the P213-P216 series. An output transformer from a portable transistor radio, such as a Mountaineer, is suitable as a matching (T2). Its primary winding (high-resistance, center-tapped) is used as winding II, and the secondary (low-resistance) winding is used as winding I. Another output transformer with a transmission ratio (transformation ratio) of 1:7...1:10 is also suitable.
Power transformer T1 - ready-made or home-made, with a power of at least 50 W and with a voltage on winding II of 20...24 V at a current of up to 2 A. It is not difficult to adapt a network transformer from a tube radio for the set-top box. It is disassembled and all windings except the network winding are removed. When winding the filament winding of the lamps (the alternating voltage on it is 6.3 V), count the number of its turns. Then winding II is wound over the network winding with PEV-1 1.2 wire, which should contain approximately four times more turns compared to the incandescent one.
Fixed resistors - MLT-0.25, variable resistors - SP-1 or similar. Capacitors C1, C4-C6, C8 - MBM or others (C8 will have to be made up of two or three parallel connected or use a capacitor with a capacity of 0.25 μF). Capacitors C2 and C7 - K50-6, SZ - K50-ZB or composed of several parallel and series connected capacitors of lower capacity or lower voltage. For example, you can use two capacitors with a capacity of 4000 μF for a voltage of 25 V (K50-6), connecting them in series. Or take four EGC capacitors with a capacity of 2000 μF for a voltage of 20 V and connect them in pairs in parallel, and connect the pairs in series. Such a chain will be designed for a voltage of 40 V, which is quite acceptable.
If there is no SZ capacitor with the specified parameters, you can use a capacitor with a capacity of about 500 μF, but assemble the rectifier using a bridge circuit (in this case, four diodes will be needed).
Diode (or diodes) - any other than that indicated in the diagram, designed for a rectified current of at least 3 A.
In Fig. Figure 9 shows a drawing of the circuit board on which most of the parts of the console are located. Powerful transistors do not necessarily need to be attached to the board with metal holders; it is enough to glue their caps to the board. The power transformer, rectifier diode and smoothing capacitor are mounted either on the bottom of the case or on a separate small strip. Variable resistors and the power switch are installed on the front panel of the case, and the input connector and fuse holder with fuse are installed on the rear wall.
If the lighting lamps are going to be placed in a separate housing, you need to connect them to the electronic part of the set-top box using a five-pin connector. True, the set-top box can look impressive even if its elements are placed in a common housing. Then a screen (for example, made of organic glass with a frosted surface) is installed in a cutout on the front wall of the case, and behind the screen inside the case the above-mentioned automobile lamps are fixed, the cylinders of which are pre-painted in the appropriate color. It is advisable to place reflectors made of foil or tinplate from a tin can behind the lamps - then the brightness will increase.
Now about checking and setting up the console. They should start by measuring the rectified voltage at the terminals of the SZ capacitor - it should be about 26 V and drop slightly at full load, when all the lamps are lit (of course, while the set-top box is operating).
The next stage is setting the optimal operating mode of the output transistors, which determine the maximum brightness of the lamps. They start, say, with the HF channel. The base terminal of transistor VT7 is disconnected from the emitter terminal of transistor VT3 and connected to the negative power wire through a chain of a series-connected constant resistor with a resistance of 1 kOhm and a variable resistor with a resistance of 3.3 kOhm. Solder the chain with the console turned off. First, the variable resistor slider is set to the position corresponding to the maximum resistance, and then it is smoothly moved, achieving the normal glow of lamps EL1 and EL2. At the same time, they monitor the temperature of the transistor body - it should not overheat, otherwise you will have to either reduce the brightness of the lamps or install the transistor on a small radiator - a metal plate 2...3 mm thick. Having measured the total resistance of the chain resulting from the selection, resistor R5 with the same or possibly similar resistance is soldered into the attachment, and the connection between the base of transistor VT7 and the emitter VT3 is restored. It is possible that resistor R5 will not have to be changed - its resistance will be close to the resulting circuit resistance.
Resistors R8 and R11 are selected in the same way.
After this, the operation of the background channel is checked. When moving the slider of resistor R12 up in the circuit, lamps EL7 and EL8 should light up. If they work with under or over heat, you will have to select resistor R13.
Next, an audio frequency signal with an amplitude of approximately 300...500 mV is supplied to the input of the set-top box from the dynamic head of the tape recorder, and the variable resistor R1 slider is set to the top position according to the circuit. Make sure that the brightness of lamps EL3, EL4 and EL7, EL8 changes. Moreover, as the brightness of the former increases, the latter should go out, and vice versa.
During operation of the set-top box, variable resistors R4, R7, RIO, R12 regulate the brightness of the flashes of lamps of the corresponding color, and R1 - the overall brightness of the screen.
3.4. CMP on LEDs (http://radiozuk.ru/)
The description is poor both in style and in content, so I will give only the main points.
A variable resistor regulates the input signal level. The switch turns on the LEDs without music (Fig. 10).
A correctly assembled circuit starts working immediately. The only thing you need to do is select R* if you need to turn on several LEDs in parallel. For example, the author has R=820 Ohm for 4 LEDs.
The circuit of the entire set-top box consists of 3 channels (Fig. 11), differing in the ratings of the filter parts. Reel L1 is the playback head from an old tape recorder.
3.5. Color music - what could be simpler? (http://cxem.net/sound/light/light23.php)
the author asks and gives the following arguments -->
Are you a beginner radio amateur and have nothing to do? Do you want to solder something, but can’t decide on the choice? Let's make color music! Let's set up a disco at home and let's rock it, but first we'll turn on the soldering iron and solder a little. We don’t want a disco, we’ll just put him in a corner near the computer and let him blink to the music.
The color-music installation allows you to receive color flashes in time with the melody being played. First, let's take a transistor, an LED, a resistor and a 9V power supply. Let's connect the sound source and apply voltage - fig. 12.
And what do we see? The LED flashes to the rhythm of the music. But it blinks annoyingly at the volume level. And here the question of audio frequency separation arises. Filters made of capacitors and resistors will help us with this. They only pass a certain frequency, and it turns out that the LED will blink only for certain sounds. 
The diagram (Fig. 13) shows an example of simple color music. But this is only a small set-top box, with insignificant brightness. It consists of three channels and a preamplifier. The sound is supplied from the linear output or low-frequency amplifier to a transformer, which also requires galvanic isolation. A small-sized network one is suitable, the secondary winding of which is supplied with an audio signal. You can do without it if the input signal is enough to flash the LEDs. Resistors R4-R6 regulate the flashing of the LEDs. Next come the filters, each of which is tuned to its own frequency bandwidth. Low-frequency - transmits signals with a frequency of up to 300 Hz (red LED), mid-frequency - 300-6000 Hz (blue), high-frequency - from 6000 Hz (green). Almost any transistors are suitable, n-p-n structures with a current transfer coefficient of at least 50, it is better if more, for example the same KT3102 or KT315.
Have you assembled a reliable, perfectly working color music device, but is something missing? Let's modernize it!
Let's start with the most important thing. Let's increase the brightness. For this we will use 12 volt incandescent lamps. We add thyristors to the circuit (Fig. 14) and power the device from a transformer. Thyristor is a controlled diode that allows you to control a powerful load using weak signals. When direct current passes through it, it remains in the open state even without a control signal; with alternating current, the operating principle is similar to that of a transistor. It has an anode, a cathode - like a diode, and an additional control electrode. It is able to withstand a decent load, so it is used in a circuit to control incandescent lamps.
The sound signal is supplied from a low-frequency amplifier with a power of 1-2 watts. Thyristors are almost any, designed for the current of lamps, lamps - automobile lamps at 12 volts. The transformer must supply sufficient current (1.5-5 amperes) depending on the lamps (Fig. 15). 
If you have experience working with mains voltage, then the best option would be to use 220-volt lighting lamps. In this case, a network transformer will not be needed, but it is better to leave the sound transformer to protect the sound source. In this case, everything must be carefully insulated and placed in a reliable housing.
Now let's do the background lighting. It will work in reverse to the main channels: if there is no sound, the LED lights up constantly, sound is supplied - the LED goes out (Fig. 16). You can make one common background channel or several with separate sound filters and connect according to the previous scheme.
A resistor (R2) is added to the circuit to constantly open the transistor. Therefore, current passes through the LED freely, but the sound signal is able to close the transistor, and the LED goes out.
Let's replace the transformer with a transistor amplifier (Fig. 17).
Getting rid of audio wire using a microphone. Let's add it to the previous diagram. Now color music will respond to all surrounding sounds, including conversation.
The diagram (Fig. 18) shows an example of a two-stage microphone amplifier. Resistor R1 is needed to power the microphone, R2 R6 sets the offset, R4 sets the sensitivity. Capacitors C1-C3 pass the alternating audio signal and do not allow it to pass DC. Microphone – any electret. If the circuit is used simply as a preamplifier, then R1 and the microphone are removed, the audio signal is supplied to C1 and the power supply minus. The ratings of the parts are not critical; special accuracy is not important here. The main thing is not to make mistakes and you will succeed.
Scheme Fig. 15 is, as it were, a “transition” from transistor DMPs to thyristor ones.
Thyristor CMPs allow you to use lamps with a power of even kilowatts as a load!
In passing, I will note that there are circuits of thyristor digital microscopy modules that use fluorescent and pulsed lamps, but I will not give them.
In Fig. Figure 19 shows a diagram of the most primitive color and music installation for three channels. This DMU includes the simplest passive filters on RC elements, the output signals of which control thyristor switches. The emitters are powered directly by N! from 220 V network.
The top one in the diagram is a low-pass filter, adjustable to a frequency of 100...200 Hz, below the diagram is a mid-range bandpass filter (200...6000 Hz), and at the bottom is a high-pass filter (6000...7000 Hz). The LF, MF and HF channels correspond to red, green and blue lamps. Since this circuit does not contain a pre-amplifier, the input signal must have an amplitude of 0.8...2 V. The signal level is adjusted using resistor R1. Resistors R2, R3. R4 are designed to regulate signal levels for each channel separately.
Transformer TP1 is made on a Ш16x24 core made of transformer steel. Winding I contains 60 turns of PEL 0.51 wire. winding II - 100 turns PEL 0.51. Any other small-sized transformer (for example, from transistor receivers) with a ratio of turns in the windings close to 1:2 can be used. Thyristors must be installed on heat sinks if the total lamp power per channel exceeds 200 W.
The presented 3-channel DMU is very easy to manufacture, but has many disadvantages. This is, firstly, a large required input signal level, secondly, a low input impedance, and thirdly, a sharp blinking of the lamps caused by the lack of compression and the primitivism of the filters used.
Rice. 20 – this ancient photograph shows the DMP (highlighted in color), which I soldered according to the above circuit around 1981. Signal source – Dnepr-12N tape recorder, output optical device– a square screen in which two mutually perpendicular layers of thin hollow glass tubes are used as light-scattering elements.
True, we didn’t have the Internet then, and I took the diagram from the brochure “To help the radio amateur,” no. 87, S. Sorokin, Volumetric Central Medical Museum “Harmony”.
In Fig. Figure 21 shows a diagram of a similar simple color and music console based on thyristors D1-DZ. It contains three color and one background channels. The set-top box is powered from an AC mains voltage of 220 V using a rectifier mounted on diodes D4-D7 in a bridge circuit. The negative wire of the rectifier is connected to the cathodes of all thyristors, and the positive wire is connected to the anodes of the thyristors through incandescent lamps L1, L2, L3. The total power of lamps included in each channel should not exceed 300 W. Backlight lamp L4 is connected in parallel to thyristor D2.
From the output of the ULF receiving device (radio, electrophone) - the voice coil of the dynamic head - the low-frequency signal goes to connector Gn1 and variable resistor R1. From the motor of this resistor, the low-frequency voltage is supplied to winding I of transformer Tr1. The secondary winding II of this transformer is connected to the input of the filters of all three channels. Variable resistor R1 is used to correct the signal level at the filter input. The need for this resistor is due to the fact that when the signal is large, lamps L1-L3 turn on and off simultaneously, in time with the change in volume. In this case, changing the tonality does not affect the operation of the lamps. This is where the imperfection of separation filters comes into play. This drawback can be partially overcome by using resistor R1, which allows for more precise switching on and off of the lamps of individual channels.
Step-up transformer Tr1 ensures reliable unlocking of thyristors D1-D3. Typically, for this, the input voltage on the secondary winding of the transformer, i.e., at the input of the filters, should be about 2-3 V. At the same time, the voltage on the voice coil of the tape recorder (player, receiver) may be lower than this value. In addition, the transformer decouples the AC network from the tape recorder with which the CMP operates, which is necessary to comply with safety regulations.
Filter C1R3 passes high frequencies, attenuating low and mid frequencies. The high-frequency channel lamp (L1) is painted blue. Filter R4С2С3 passes mid frequencies, weakening low and high frequencies. Finally, the R4R6C4 filter passes the lower frequencies, attenuating the highs and mids. In the mid and low frequency channels, lamps L2, L3 are colored green and red, respectively.
The console works as follows. If there is no signal, all thyristors are closed and the lighting lamps L1, L3 in the high and low frequency channels do not light up. The mid-frequency channel will glow at full intensity (all voltage from the rectifier output is divided equally between green and yellow lamps). When a low-frequency signal appears at the output of the filter of this channel and its value is sufficient to open thyristor D2, the background lamp L4 will go out (it will be short-circuited by the open thyristor), and lamp L2 will light up at full intensity. Accordingly, lamps L1 and L3 will light up only when the voltages at the output of the high- and low-pass channel filters become sufficient to open thyristors D1 and D3.
It should be recalled that the thyristor opens only with the positive half-wave of the low-frequency signal and closes every half-cycle of the alternating mains voltage.
When making a set-top box, you can use fixed resistors MLT-1 or MLT-0.5, a variable resistor R1-wire, of any type; permanent capacitors MBM or others for an operating voltage of at least 400 V. Transformer Tr1 is made on a Ш 12Х12 core. Primary winding I contains 210 turns of PEL-1 0.2 wire, winding II contains 3200 turns of PEL-1 0.09.
The KU201K thyristor can be replaced with 2U201K, 2U201L, KU201L, 2U201Zh and the like. The rectifier can operate diodes (D4-D7) D243A, D245A, D246A, which without additional heat sinks are capable of providing a load current of about 5 A.
The design of the console can be very diverse. However General requirements come down to compliance with safety precautions, since here there is also direct contact with the N network! 220 V. Reliable insulation of the circuit board with diodes and thyristors must be ensured. The latter should be installed under the nut on an additional heat sink, for which you can use strips of brass or duralumin 3-4 mm thick and 50 X 150 mm in size. Installation of heat sinks with thyristors and other parts is carried out on a board made of getinax or textolite 3-4 mm thick. If the attachment is assembled from obviously tested and serviceable parts and the installation is done correctly, it starts working immediately. Having set the handle of the variable resistor R1 to the lowest position according to the diagram, connect the mains voltage 220 V and apply some kind of voltage to the input of the set-top box from the output of the receiver, electrophone or tape recorder music program. Then, by gradually increasing the voltage at the input of the low-frequency filters with resistor R1, stable operation of the set-top box and the best combination of colors on the screen are achieved. Screens can be of any design. Some radio amateurs design screens in the form of decorative table lamps or spotlights installed at different ends of the room and the light from them is directed into the middle of the ceiling.
4.2. Color music console (RADIO, 1972, No. 4)
Material from my personal PAPER archive (scanned 01/17/2013)
Using this scheme, I assembled my first digital MP using KU201L thyristors in 1979. The set-top box worked on 12 V car light bulbs. I don’t remember why it wasn’t given a finished look. 
Rice. 22.
The device implements the “running lights” effect, but the frequency of the multivibrator depends on the magnitude of the sound signal supplied to the input of the device. Of course, the word “color-musical” in the title of the article is used inappropriately. However, the device allows you to realize an interesting effect when not only the speed of the “running lights” changes, but also the direction of the “running” depending on the volume of the sound signal.
In my opinion, this is the device that should have been used in the previous design.
My version of the device is shown in Fig. 32: 
6. LAMP CMP
6.1. RADIO, 1965, No. 10 
DMP on tubes makes it possible to obtain good frequency characteristics of the filter, because the circuit provides for matching the source and load with the filter. In this case, a filter made on RC elements is easier to manufacture and adjust. The final stages in each channel are assembled according to a circuit with a common anode.
The operating mode of the cascade is chosen such that in the absence of a signal on the control grid of the lamp, the anode current is very small and does not heat up the garland lamps. The anode current is adjusted by variable resistances R17, R18, R19.
The final stages are controlled by rectified voltage after the signal is amplified by the second stages.
The signal is rectified by the second triodes of lamps L2, L3, L4 in a diode connection. Only positive voltage reaches the control grids of the final stage lamps, which unlocks the lamps.
Potentiometers R4, R9, R14 at the input of the second amplifier stages regulate the gain of each channel. Using potentiometer R1, the overall brightness of all garlands is set. Device dimensions 180x150x260 mm.
Radio tubes should be replaced with domestic ones: 12АХ7 - 6Н2П, 6CL6 - 6П9, 6П18П, 5Y3 - 5Ц3С.
6.2. Color music installation, A. Aristov, Pervouralsk (“UT for skillful hands”, 1981, No. 4)
Material from my personal PAPER archive (scanned 01/18/2013)
We propose to make a simple but good color music installation (CMU) using thyratrons.
The thyratron has a high (tens of megaohms) input circuit resistance and high sensitivity to input signals. Therefore, the input signal is supplied without preliminary amplification. Transformer Tr1 increases the input voltage by 5-8 times and completely isolates the installation input from the supply network. Then, through the sensitivity regulator R9, the signal is fed to simple RC filters: HF - C1R1R2, MF - C2C3R5R6, LF - R10C4 and, as usual, is divided by them into three channels. After the filters, the control signals are sent to the control grids (leg 1) of the thyratrons. These same legs receive a negative bias voltage through resistors R3, R7, R11, which is regulated by variable resistors R4, R8, R12. An RC filter loaded onto the high resistance of the thyratron works more efficiently, stably and does not require adjustment. That is why the proposed installation creates a beautiful picture on the screen, which attracts radio amateurs. More than a hundred people made it in Pervouralsk.
The anode circuits of thyratrons include ordinary 220 V lighting lamps. The power of odd lamps (H1, H3, H5) is approximately 2.5 times more power even lamps. Therefore, when no signal is supplied to the channel and the thyratron is closed, the even and odd lamps are switched on in series, the even lamp glows fully, and the odd lamp glows barely noticeably. When an input signal appears, the thyratron opens and short-circuits the even lamp. It goes out, and the odd lamp glows at full intensity. This scheme makes it possible not to introduce a special backlight channel, and also to increase the service life of the thyratron several times. The latter is explained by the fact that in our circuit the lamps are constantly heated. If they were allowed to cool to room temperature, their resistance would decrease several times, and the destructive surge of current at the moment the thyratron was turned on would increase by the same amount.
The anode circuits of the thyratrons are powered through a rectifier using diodes V6-V9. The filament circuits are powered from the secondary winding of the filament transformer T2. From the same winding, through a rectifier with doubling the voltage on diodes V4, V5, the thyratron bias circuits are powered
It is best to assemble the CMU on a textolite panel 2-4 mm thick. The design and dimensions depend on the available parts, and therefore we do not describe them. Variable resistors can have a resistance of 15-68 kOhm. D9Zh diodes can be replaced with any low-power diodes designed for a voltage of at least 20 V, KD209A - KD209 or KD105 diodes with any letter index, D226, D7Zh. Lighting lamps must have a power of 40 and 15 W. It is not recommended to increase the lamp power. Lamp H1 can be painted with red nitro paint, H3 with yellow, H5 with green, the rest with blue or purple. Transformers can be taken from the Record-311 radio (output and power). The output transformer T1 (iron Ш16х18) has been redone. One of its windings (II) is preserved (2800 turns of PEL-0.12 wire), instead of the other (I) 400 turns of PEL-0.33 wire are wound. Between the windings you need to lay several layers of varnished fabric. This insulation ensures safety. The power transformer was used without modification. It is wound on a magnetic circuit Ш21х26. Winding I contains 1250 turns of PEL-0.29 wire, winding II contains 40 turns of PEL-0.9. You can use other transformers with similar parameters.
There is no need to adjust an error-free installation. If the bias regulator is set to the right position according to the diagram, thereby removing the bias voltage, the thyratron will open and turn on the lighting lamp even in the absence of a signal. This allows you to check the functionality of the channel. The offset controls are also channel sensitivity controls. But we must remember that an excessive increase in sensitivity will negatively affect its stability.
7. Output optical devices of the DMP.
As practice shows, a good effect of perceiving the color accompaniment of music can be achieved not so much by complicating the set-top box circuit, but by a well-thought-out, original design of the VOU.
This issue has been repeatedly addressed in the literature (see paragraphs 5.2, 5.4, 5.6).
7.1. Of course, the simplest option is to use the ceiling or walls as a screen, where the luminous flux of powerful emitters of thyristor CMPs is directed.
7.2. The second option is more labor-intensive, but more varied, and, therefore, more effective. This is the manufacture of a HEU in the form of a box, the front wall of which is a screen made of some transparent material. The main attention in this case is on the light-diffusing material and the location of the lamps behind the screen. Used for both transistor and thyristor DMPs.
7.3. The most interesting are HEUs of original designs, which implement the principle of “three-dimensionality” of the color picture.
Here we can distinguish a group of HEUs in which the “three-dimensionality” is realized due to the original design (not flat) of the diffuser and the special arrangement of the emitting lamps. But such HEU are static.
I would include HEUs in another group, in which not only “three-dimensionality” is realized, but also the pseudo-dynamics of the color picture. This is achieved by the effect of “running lights”, used in conjunction with the “classical” DMP.
The third group consists of HEUs, in which “volume” is combined with real dynamics. Stencils, lenses or other transparent scattering objects, or opaque ones, but capable of scattering light and changing their shape during movement, can move in such HEU.
EXAMPLES
1. RADIO, 1971, No. 2 - instead of lamps, electromagnets are installed at the output of the CMP, which control light filters that block the constant light flux. 
2. RADIO, 1975, No. 8 – selection of materials 
3. RADIO, 1976, No. 4 – color and music lamp 
4. RADIO, 1978, No. 5 – selection of materials 
The author's designs contain interesting and varied ideas for creating a HEU for the CMP: from a rotating cubic stencil inside a cubic screen (Fig. below left, B. Galeev, R. Galyavin, Central Medical Unit "Yalkyn") to the use of an air humidifier (Fig. below right). I tried to search the Internet for the designs of the original HEU, but was very disappointed: no variety, no innovative ideas, no imagination.
There is not even a practical implementation of what was invented long ago.
“It’s sad, girls...”, as the great schemer said.
I am still inclined to call devices of the second type CMP - color music consoles, thereby emphasizing their independence from the subjective perception of music.
The microprocessor also needs to be programmed.
With a lighting part, Scriabin's musical poem "Prometheus" was first performed on May 20, 1915 at New York's Carnegie Hall by the Orchestra of the Russian Symphony Society conducted by Modest Altshuler. For this premiere, Altshuler ordered a new light instrument from engineer Preston Millar, to which the inventor gave the name “chromola” (eng. chromola); The performance of the lighting part caused numerous problems and was coldly received by critics.
CMP - color music consoles - that's what I call lighting devices automatic accompanying music.
Transistors in such DMPs are power elements in circuits that control radiating elements.
Thyristors in such CMPs are power elements in circuits that control radiating elements.
The schemes of these DMPs “wander” from site to site. I soldered such consoles when we had never even heard of the Internet.
If L4 is taken to have half the power of L2, then in the absence of a signal L4 will glow with almost full intensity, and with a maximum signal, on the contrary, L2 will glow.
OOU – output optical device.
Structurally, any color and music (light and music) installation consists of three elements.
Control unit, power amplification unit and optical output device.
As an output optical device, you can use garlands, you can design it in the form of a screen (classic version) or use electric directional lamps - spotlights, headlights.
That is, any means are suitable that allow you to create a certain set of colorful lighting effects.
The power amplification unit is an amplifier(s) using transistors with thyristor regulators at the output. The voltage and power of the light sources of the output optical device depend on the parameters of the elements used in it. The control unit controls the intensity of light and the alternation of colors.
In complex special installations designed to decorate the stage during
various types
shows - circus, theater and variety performances, this block is controlled manually.
Accordingly, the participation of at least one, and at most, a group of lighting operators is required.
If the control unit is controlled directly by music and works according to any given program, then the color and music installation is considered automatic.
It is precisely this kind of “color music” that novice designers - radio amateurs - have usually assembled with their own hands over the past 50 years. The simplest (and most popular) “color music” circuit using KU202N thyristors. This is the simplest and perhaps the most popular scheme for a color and music console based on thyristors.
Thirty years ago I first saw a full-fledged, working “light music” up close. My classmate put it together with the help of my older brother. It was exactly this scheme. preamplifier power by 1-2 watts. My friend had to turn his “Electronics” almost “all the way” in order to achieve fairly stable operation of the device.
A step-down transformer from a radio point was used as an input transformer. Instead, you can use any small-sized step-down network trans.
For example, from 220 to 12 volts. You just need to connect it the other way around - with a low-voltage winding to the amplifier input.
Any resistors, with a power of 0.5 watts. Capacitors are also any; instead of KU202N thyristors, you can take KU202M.
"Color music" circuit using KU202N thyristors, with active frequency filters and a current amplifier.
The circuit is designed to operate from a linear audio output (the brightness of the lamps does not depend on the volume level).
Let's take a closer look at how it works.
The audio signal is supplied from the linear output to the primary winding of the isolation transformer.
From the secondary winding of the transformer, the signal goes to active filters, through resistors R1, R2, R3 regulating its level.
Separate adjustment is necessary to configure the high-quality operation of the device by equalizing the brightness level of each of the three channels.
Using filters, signals are divided by frequency into three channels. The first channel carries the lowest frequency component of the signal - the filter cuts off all frequencies above 800 Hz. The filter is adjusted using trimming resistor R9. The values of capacitors C2 and C4 in the diagram are indicated as 1 µF, but as practice has shown, their capacity should be increased to at least 5 µF. The filter of the second channel is set to medium frequency - from approximately 500 to 2000 Hz. The filter is adjusted using trimming resistor R15. The values of capacitors C5 and C7 in the diagram are indicated as 0.015 μF, but their capacity should be increased to 0.33 - 0.47 μF. The third, high-frequency channel carries everything above 1500 (up to 5000) Hz.
Next comes the optical device, the design and external design of which depends on the designer’s imagination, and the filling (lamps, LEDs) depends on the operating voltage and maximum power output stage.
In our case, these are 220V, 60W incandescent lamps (if you install thyristors on radiators - up to 10 pcs per channel).
The order of assembling the circuit.
About the details of the console.
KT315 transistors can be replaced with other silicon ones npn transistors with a static gain of at least 50. Fixed resistors - MLT-0.5, variable and tuning - SP-1, SPO-0.5. Capacitors - any type.
Transformer T1 with a ratio of 1:1, so you can use any one with a suitable number of turns.
If you make it yourself, you can use a Sh10x10 magnetic circuit, and wind the windings with PEV-1 wire 0.1-0.15, 150-300 turns each.
The diode bridge for powering thyristors (220V) is selected based on the expected load power, minimum 2A. If the number of lamps per channel is increased, the current consumption will increase accordingly.
To power transistors (12V), you can use any stabilized power supply designed for an operating current of at least 250 mA (or better, more).
First, each color music channel is assembled separately on a breadboard.
Moreover, the assembly begins with the output stage. Having assembled the output stage, check its functionality by applying a sufficient level signal to its input.
If this cascade works normally, an active filter is assembled. Next, they check again the functionality of what happened.
As a result, after testing we have a really working channel.
In a similar way, it is necessary to collect and rebuild all three channels.
Such tediousness guarantees the unconditional functionality of the device after “fine” assembly on the circuit board, if the work is carried out without errors and using “tested” parts.
