How to make tube amplifiers Hi-End own hands?

People who love good music probably know about the Hi-End tube amplifier. It can be done by yourself if you are able to use a soldering iron and have any knowledge of working with radio engineering.

Unique device

Lamp amplifiers Hi-End is a special class of household appliances. What is the reason for this? First, they have a rather interesting design and architecture. In this model, a person can see everything that he needs. This makes the device truly unique. Secondly, the characteristics of a tube amplifier Hi-End differ from alternative models in which transistor-integrated circuits are used. The difference between Hi-End is that the minimum number of parts is used during installation. Also, when evaluating the sound of this device, people trust their ears more than measuring non-linear distortions and an oscilloscope.

Choice of schemes for assembly

The preamplifier is quite simple to assemble. For him, you can choose any suitable scheme and begin the assembly. Another case is the output stage, that is, the power amplifier. With him, as a rule, there are many different questions. The output stage has several types of assembly and operating modes.

The first type is a single-cycle model, which is considered a standard cascade. When operating in the "A" mode, it has small nonlinear distortions, but, unfortunately, has a rather poor efficiency. Also note the average output power. If you need to fully voice a fairly large room, you will need to use a two-stroke power amplifier. This model can work in the "AB" mode.

In a single-cycle circuit, only two parts are sufficient for good operation of the device: a power amplifier and a preamplifier. The two-stroke model already uses a phase-inverter amplifier or driver.

Of course, for the two types of output stage, in order to comfortably work with the speaker system, it is necessary to match the high interelectrode resistance and the low resistance of the device itself. This can be done with a transformer.

If you are a connoisseur of "tube" sound, you should understand that you need to use a rectifier, which is produced on a kenotron, to achieve this sound. In this case, you can not use semiconductor parts.

Developing a tube amplifier Hi-End, you can not use complex schemes. If you need to sound a small enough room, then you can apply a simple single-cycle design, which is easier to make and configure.

Hi-End lamp amplifier with own hands

Before starting the installation it is necessary to understand some rules for assembling such devices. We will need to apply the basic principle of installing lamp devices - minimizing the attachments. What does it mean? You will need to cancel the installation wires. Of course, this is not always possible to do, but their number must be minimized.

In a good tube amplifier Hi-End, mounting lobes and straps are used. They are used as additional points. This assembly is called a hinged assembly. Also you will need to remove the resistors and capacitors that are on the lamp panels. It is highly not recommended to use printed circuit boards and collect the conductors so that parallel lines are obtained. Thus, the assembly will look chaotic.

Elimination of interference

Later you need to eliminate the low-frequency background, if, of course, it is present. An important point is also the choice of the grounding point. In this case, you can apply one of the following options:

• The type of connection is a star, in which all earth conductors are connected to one point.
• The second way is laying a thick copper bus. On it it is necessary to separate the corresponding elements.

In general, it is better to find the grounding point yourself. This can be done by determining the level of low-frequency background by ear. To do this, you need to gradually close all the grids of lamps that are located on the ground. If, when closing a subsequent contact, the low-background level decreases, then you find a suitable lamp. To achieve the desired result, it is necessary to eliminate unwanted frequencies experimentally. Also, you need to apply the following measures to improve the quality of your assembly:

• To make the glow circuits of the radio tubes, you need to apply a twisted wire.
• Lamps that are used in the preamplifier should be covered with grounded caps.
• Also, earthing requires enclosures with variable resistors.

If you want to feed the glow of the pre-amp lamps, you can apply direct current. Unfortunately, this requires an additional block. The rectifier will violate the standards of the tube amplifier Hi-End, since it is a semiconductor device, which we will not use.

Transformers

Another important point is the use of various transformers. As a rule, the power and output are used, which must be connected perpendicularly. This way you can reduce the level of the low-frequency background. Transformers should be placed in grounded enclosures. It must be remembered that the cores of each of the transformers should also be grounded. Do not use a shielded wire when installing the devices, so that there are no additional problems. Of course, these are not all the features associated with editing. There are quite a lot of them, and it will not be possible to consider everything. When installing the Hi-End (tube amplifier), you can not use new element bases. They are now used to connect transistors and integrated circuits. But in our case they will not work.

Resistors

A quality tube amplifier Hi-End is a retro-instrument. Of course, the details for its assembly should be appropriate. Instead of a resistor, a carbon and a wire element can come up. If you do not spare money to develop this device, you should use precision resistors, which are quite expensive. Otherwise, the MLT models are applicable. This is quite a good element, as evidenced by the feedback.

The Hi-End lamp amplifiers are also applicable to Sun resistors. They were made about 65 years ago. It's quite simple to find such an element, it's enough just to walk along the radio market. If you apply a resistor with a power greater than 4 watts, you need to choose wire enameled elements.

Capacitors

In the installation of a tube amplifier, various types of capacitors should be used for the system itself and the power supply unit. They are usually used to adjust the timbre. If you want to get a quality and natural sound, you should use a separation capacitor. In this case, a low leakage current appears, which allows you to change the lamp operating point.

This type of capacitor is connected to the anode circuit, over which a large voltage flows. It is necessary to connect a capacitor, which maintains a voltage of more than 350 volts. If you want to apply quality elements, you need to use the details from the company Jensen. They differ from analogues in that their price exceeds 3,000 rubles, and the price of the most high-quality radioelements reaches 10,000 rubles. If you use domestic elements, it is better to choose between models K73-16 and K40U-9.

The single-ended amplifier

If you want to apply a single-cycle model, you must first consider its circuit. It includes several components:

• Power Supply;
• Terminal cascade;
• Pre-amplifier, in which you can adjust the tone.

Assembly

Let's start assembling from the preamplifier. Its installation takes place according to a rather simple scheme. It is also necessary to provide power adjustment and a separator for tone control. It must be set to low and high frequencies. To increase the expiration date, you need to apply a multi-band equalizer.

In the laughter of the preamplifier, one can see similarities to the common double triode 6H3P. The element necessary for us can be collected in a similar way, but use an end cascade. This is also repeated in the stereo version. Remember that the structure must be assembled on the circuit board. First it needs to be debugged, and then it can be installed on the chassis. If you have installed it correctly, the device should be switched on immediately. Next, go to the setting. The magnitude of the anode voltage for different types of lamps will be different, so you will need to select it yourself.

Components

If you do not want to use a high-quality capacitor, then you can apply K73-16. It will work if the operating voltage is more than 350 volts. But the sound quality will be noticeably worse. Also for such a voltage, electrolytic capacitors are suitable. The amplifier needs to connect an oscilloscope C1-65 and give a signal that will pass from the audio frequency generator. With the initial connection, you need to set the input signal to about 10 mV. If you need to know the gain, you will need to use the output voltage. To select the average ratio between low and high frequencies, it is necessary to select the capacitance of the capacitor.

You can see the photos of the Hi-End tube amplifier below. For this model, 2 lamps with an octal cap were used. A double triode is connected to the input, which is connected in parallel. The final cascade for this model is assembled on the 6T13S beam tetrode. In this element is mounted a triode, which allows you to get a good sound.

To configure and test the operation of the assembled device, you must use a multimeter. If you want more accurate values, you should use a sound generator with an oscilloscope. When you have taken the appropriate instruments, you can proceed to setup. At the cathode L1, indicate a voltage of about 1.4 volts, this can be done if you use a resistor R3. The output current must be 60 mA. To make a resistor R8, you need to install in parallel a pair of resistors MLT-2. Other resistors can be of different types. It should be noted a rather important component - the separation capacitor C3. He was not in vain mentioned, because this capacitor has a strong influence on the sound of the device. Therefore it is better to use a proprietary radio element. Other elements of C5 and C6 are film capacitors. They allow to increase the quality of transmission of different frequencies.

A power supply built on a 5C3C kenotron is worth finding. It corresponds to all rules of construction of the device. A self-made tube power amplifier of Hi-End class will have a high-quality sound if you find this element. Of course, in another case it is worth looking for an alternative. In this case, you can use 2 diodes.

For a Hi-End tube amplifier, you can use an appropriate transformer, which was used in old tube technology.

Conclusion

To make a tube amplifier Hi-End with your own hands, you need to perform consistently and accurately all the actions. To begin with, connect the power supply with an amplifier. If you properly configure these devices, you can mount a preamplifier. Also, with the help of appropriate technology, you can check all elements to prevent damage to the speaker system. After assembling all the elements together, you can proceed with the design of the device. A plywood can fit the case. To create a standard model, you need to place radio tubes and transformers on top, and you can already mount the regulators on the front wall. With these you can enhance the tone and see the power indicator.