Tip 1: How to make the most simple amplifier

Tip 1: How to make the most simple amplifier

Need for a self-made amplifier regularlyarises in guitarists. The concert set, as a rule, stands in the rehearsal room. He weighs a lot, each time to carry it with him uncomfortable, and therefore there is a desire to collect something for home rehearsals. However, at concerts such amplifier also possible to use. Its output power reaches 3.5-4 W at a rather high quality of sound.

How to make the most simple amplifier

You will need

  • - power supply from an old tube receiver or radiolink;
  • - the radio lamp and the socket to it;
  • - alternating resistance at 220 kΩ;
  • - input socket;
  • - installation wire;
  • - a piece of plywood with a thickness of 3-5 mm;
  • - a fine brass net or radio cloth;
  • - output transformer from the lamp receiver or TV;
  • - cover of the case from an old CD or DVD-drive;
  • - electric drill;
  • - a jigsaw;
  • - soldering iron, rosin, tin.

Instructions

1

In the case cover, mark and drill holesunder the panel and under the fastening of the transformer TVZ or the like. Fit the parts on the chassis cover. In the side wall, mount the socket of the input connector, a variable resistor, which is the volume control of the amplifier. If there is no switch on the power supply, mount it in the side wall. Try to make sure that all the elements mentioned are on the same side of the chassis. If the parts that you have have fixing elements, make the necessary holes for them.

2

Mount on the chassis of the radio components according to the attached diagram. Lamp while on the paste. Keep in mind that the high-resistance winding of the output transformer is turned into the anode circuit of the lamp.

3

On a separate wooden or plywood panelfasten the speakers, previously cutting out the holes for them. It can be 2 speakers of 1.5 watts from the TV or radios. Maybe 1 speaker for 3-4 W from a lamp receiver. The speakers can be of different shapes. You only need to provide a total power of at least 3 watts and the total resistance with parallel inclusion of 3-8 ohms.

4

If desired, protect the dynamics of small brassnet or radio. If you use two speakers in parallel, they must be phased. Choose the inclusion, in which the diffusers will be drawn in or pushed out at the same time, if they apply a low-voltage direct current (for example, from a battery)

5

Connect the power supply, amplifier and dynamics so as to apply a variablethe voltage is 6.3V. Connect the constant anode voltage to 210-300 V, and connect the negative to the chassis body. Connect to the output (low resistance) winding of the output transformer of the dynamics. Insert the lamp into the panel. Turn on amplifier in the network. If it is assembled correctly, after two or three minutes of warm-up, it will be ready for operation. If, at the same time, a loud buzzing sound is heard from the speakers, you need to swap the wires connecting them to the output transformer.

6

Using a guitar cable, connect amplifier with an electric guitar. Adjust the volume of the amplifier to achieve the greatest sound power .. When the guitar controller should be set to the maximum volume. This amplifier usually does not require additional adjustments and settings.

7

From the plywood make the body. The power supply can be located at the bottom, and the chassis of the amplifier - above it. Other layouts are possible. If desired, you can decorate the body with imitation leather, mount handles on it for carrying, etc.

Tip 2: How to make a simple sound amplifier

Amplifier low-frequency, assembled on an integralchip, it is convenient that does not require adjustment after the assembly. One of the most common microcircuits for use in such amplifiers is the LM386.

How to make a simple sound amplifier

Instructions

1

Connect the second and fourth pins of the LM386 to the common wire.

2

Connect the sixth pin of the IC to the power bus (+6 volts), but do not feed this bus yet.

3

Take the variable resistor by ten kilo. Arrange it with the handle upwards, conclusions to itself. Connect the left output of the resistor to the common wire, connect the middle to the third pin of the microcircuit, the right one to the output of the signal source. The volume control turned out.

4

Collect the so-called corrective chain. To do this, connect in series a capacitor with a capacitance of about 0.05 μF and a resistor with a resistance of about 10 Ω. This chain is included between the fifth pin of the chip and the common wire.

5

One of the conclusions of the speaker with an impedance of 8 ohms is connected to the fifth pin of the chip through an electrolytic capacitor with a capacity of 100 to 500 μF (plus to the chip), and the other to the common wire.

6

Such an amplifier has a gain,equal to 20. To increase it by a factor of ten, you will need two more capacitors. One of them, with a capacity of 0.1 μF, connect between the seventh pin of the chip and the common wire. The second, electrolytic, with a capacity of 10 μF, connect between the first and eighth leads (plus to the first).

7

If the 200-fold gain is too large and the 20-fold is too small, make it equal to 50. To do this, in series with a 10 μF capacitor, turn on the resistor at 1 kΩ.

8

If desired, enter an additionalraising low frequencies. To do this, replace the 10 μF capacitor with another capacitor from 0.02 to 0.05 μF, and increase the resistance of the resistor connected in series tenfold.

9

Set the volume control to minimum, apply power to the amplifier and the input signal, then gradually increase the volume to the desired level.

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