Microphone - a device that converts sound vibrations into electricity... In sound transmission, the microphone is the primary link in sound reception. A microphone is a useful device that can be used to communicate on the Internet, as well as to record voices or sounds (instruments, special effects). However, high-quality microphones cost a lot of money, and cheap ones cannot provide sufficient sensitivity and quality.

In this article, we will show you how to make a microphone suitable for daily use with your own hands.

What can a homemade microphone be used for?

Of course, making a condenser microphone for vocals or podcasts with your own hands is almost impossible - their device is too complicated, which can become a hindrance for a person who is poorly versed in electronics.

Electret microphones are much simpler in design and therefore more reliable. In addition, the small size and low cost of electret microphones allow them to be used almost anywhere that sound reception may be required.

Here is a simple way to make such a microphone with your own hands.

What do you need?

• Electret capsule - can be removed from the old cell phone or a radio tape recorder;
• Jack 3.5 plug for connecting a microphone to a computer;
• Microphone housing - a syringe barrel will work well;
• Paper clip - for fixing the case and further attaching the microphone, for example, to clothing;
• Thin wire - cut a small section 1-1.5 meters long;
• Black foam is a small piece for protection from the wind.

Manufacturing procedure

To make it easier for you to navigate - look on the Internet for photos of a homemade microphone or a standard electret microphone ("lapel") device.

• Make a microphone body - you need to cut off the tip from the syringe body with a knife. You can erase the divisions on the syringe with a solvent;
• Pass a wire through the cone of the syringe and tie a knot at its end to secure the microphone in the body;
• Solder the electret capsule to the wire from the side of the assembly - connect the shielded braid to its body;
• Install the capsule into the body, and secure the cone with the tab of the clerical clip;
• Solder the other end of the wire with the plug, additionally connecting the left and right channels together;
• Make a narrow round hole for the microphone in a piece of foam rubber. You can cut off extra corners with a knife - this way you get a decent windproof cap.

That's all, homemade microphone ready! You managed to create a sensitive measuring microphone with your own hands, which is also well suited for communication.

DIY microphone stand

As a rule, expensive and high-quality microphones are bought for serious work or hobbies, be it professional sound recording, broadcasting or hobby for vocals.

In the overwhelming majority of cases, for comfortable work and for the closest access to the sound source, such microphones have to additionally purchase a special stand. Now we are going to show you how to make a desktop microphone stand at home.

What do you need?

Clamp Lamp - Available from any electronics store. Attention: the mass of the lamp must correspond to the mass of your microphone, otherwise the microphone on a weak clamp will easily fall under its own weight.

The holder depends on the type of your microphone: for a dynamic microphone, the holder can be purchased at a price of 250 rubles, for a condenser ("spider" type) - at a price of 500 rubles.

It is possible to find and purchase an adapter for a microphone holder for easy installation on a clamp.

Manufacturing procedure

• Cut and pull out the lamp wire;
• Disassemble and remove the lamp cover;
• Attach the microphone mount to the thread to the lamp pantograph - due to a thread mismatch, the microphone mount can be screwed on only once;
• Attach the microphone holder to the mount;
• Install the microphone itself in the holder, fix the stand to the table.

Ready! Now you have a convenient, adjustable microphone stand that can be easily attached to the table, and the clamp design allows you to screw a pop filter and other accessories to it.

DIY microphones photo

Almost all headsets that are designed to work with a PC have such "pathetic" characteristics that if you try to use a microphone from such a headset for sound recording or the same karaoke, you will get nothing but disappointment. There is only one reason for this - all such microphones are designed for speech transmission and have a very narrow frequency range... This not only reduces the cost of the design itself, but also contributes to the intelligibility of speech, which is the main requirement of the headset.

Attempts to connect an ordinary dynamic or electret microphone usually end in failure - the level from such a microphone is clearly not enough to "swing" the sound card. In addition, ignorance of the input circuit of sound cards affects and the incorrect connection of a dynamic microphone ends the matter. Collect a microphone amplifier and connect it "according to the mind"? It would be nice, but much easier to use the IEC-3 microphone, which was at one time widely used in wearable equipment and is still quite common. But, of course, you will have to connect "according to the mind".

This microphone is electret, has rather high characteristics (the frequency range, for example, lies in the range of 50 - 15,000 Hz) and, most importantly, it has a built-in source follower assembled on field-effect transistor, which not only matches the high impedance of the microphone with the amplifier, but also has an output level more than sufficient for any sound card. Perhaps the only drawback is that the microphone needs power. But its current consumption is so small that two AA batteries connected in series will last for many months of continuous operation. Let's take a look at internal scheme microphone, which is located in an aluminum glass, and think about how to connect it to a computer:

The gray color indicates an aluminum cup, which is a shield and is connected to the common wire of the circuit. As I already said, such a microphone requires external power, and minus 3-5 V must be applied to the resistor (red wire), and plus to the blue one. We will shoot a useful signal from the white one.

Now let's take a look at the computer microphone input diagram:

It turns out that the signal should be applied only to the very tip of the connector, indicated in green, and to the red itself sound card supplies +5 V through a resistor. This is done to power the headset preamplifiers, if used. We will not use this voltage for two reasons: firstly, we need a different polarity, and if we just “turn” the wires, then the microphone will “hum” strongly. Secondly, the PC power supply is impulse and the noise at these five volts will be decent. The use of galvanic cells is ideal in terms of interference - pure "constant" without the slightest ripple. So, the complete diagram of connecting our microphone to a computer will look like this.

I think not all owners of ordinary, budget (cheap) microphones for a computer or laptop are completely satisfied with the sound quality and volume. Typically such microphones, headphone, lavalier or tabletop type, have the following device. There is a plastic microphone housing itself, inside which there is an electret-type microphone capsule. Such electret capsules are called condenser microphones. The capsules are quite small, their quality (if it is relatively cheap) is very good. They have connection polarity (plus and minus). A two-wire, sufficiently flexible wire is soldered to this capsule, which is connected with its second end to a 3.5-type plug.

This microphone can be improved by making it sound much louder and better. I propose a diagram containing just a few details. This is a simple microphone amplifier. Despite its simplicity, this circuit makes the sound of the microphone capsule really much better. Moreover, the amplifier is powered from the same wire through which it goes sound signal... Note for those who do not know! The microphone socket of the computer has three contacts, one of which is the case, it is also a minus for the microphone, the second contact is a plus (the constant voltage on it is about 2.5 V) and the third contact is signal. In the circuit, the signal and positive terminals are combined.

Now about the very circuit of this microphone amplifier. After the microphone capsule itself there is a C1 capacitor, which filters high-frequency noise. The circuit will work fine without it, but it is still better to install it. Also, an electret-type microphone capsule (condenser, also called) needs phantom power. It is fed through resistors R1 and R3. Resistor R2 is a trimmer type, it can adjust the amount of amplification of the microphone sound. All resistors are 1 kilohm. Capacitor C2 has a capacity of 47 microfarads, its voltage can be anything. Note that it has a plus and a minus.

A bipolar transistor of the KT3102 type is supplied to the microphone amplifier circuit. This low-power transistor has a fairly high gain. It has n-p-n conductivity. Instead, you can put any other, with similar characteristics, for example, the same KT315. Moreover, when choosing another transistor, it is the high gain that is important, and not its power. Well, do not confuse the type of conduction (transistors type p-n-p are not suitable for use in the circuit). It is this transistor that makes the amplification of the microphone sound. The signal from the microphone capsule arrives at its base, and in the collector circuit we already have an increased amplitude of this signal.

Amplified signal through the wire goes to the audio plug type 3.5. As you can see in the diagram, you need to solder two contacts together, this is a plus and a signal one. It is also important that the wire from the microphone to the plug is shielded. As practice has shown, the difference between shielded and non-shielded wires is tangible. A wire without a screen is affected by various external electromagnetic interference coming from the network, high-frequency devices, etc. Unfortunately, budget microphones initially have a wire without a screen. So, if possible, replace this wire with a shielded one, you will immediately feel a positive difference.

In addition to shielding the wire, you will also need to make a screen on the circuit itself. For example, after I soldered the circuit, which turned out to be small enough, place it inside a plastic syringe (2 cubes). On top of the syringe body, I wound several layers of ordinary foil, which I electrically connected to the minus of the microphone amplifier circuit. As a result, it turned out that the entire signal path from the microphone capsule itself to the plug is shielded. After checking, it turned out that with such shielding, external electromagnetic interference and various pickups were practically reduced to zero.

Besides important point is the presence of the so-called wind protection. This is that little foam cover that you put on over the microphone. This cover greatly reduces the effect of whimpering from the speaker's lips into the microphone itself. That is, when we put the microphone head directly in front of us, then those air flows that have a dull, sobbing character are not reproduced in the best way after amplification. acoustic system... Foam rubber largely attenuates these unpleasant sounds. So this foam cover is a must.

And one more important point. This is a selection of microphone capsules. Let's say I had 20 of these capsules. Many of them looked almost the same. I decided to check them all the same, but is there a difference between them? I connected these mic capsules one at a time to this DIY amplifier. Then, on the computer, he made a sequential recording of the same sounds with each of the available capsules. As a result, despite the similarity (in appearance), their sound characteristics are very different. Out of 20 pieces, only 4 showed themselves from the highest quality side. They produced clear sound, good volume, minimum noise and interference, and a wide range of reproducible frequencies. So not all mic capsules are the same!

Videos on this topic:

P.S. If, before soldering this circuit of a simple microphone amplifier, I was suspicious of the final result (the circuit was too simple). Then after I soldered it, I picked up the best microphone capsule, put the shielding on the wire and the microphone amplifier case itself, I was convinced of good quality of this circuit. The sound that can be obtained using the normal budget microphone and after soldering the amplifier with its improvements, it was very different. This simple microphone amplifier makes the sound much better, louder, cleaner. So I advise you to collect it for your needs.

Microphone preamplifier he is preamplifier or an amplifier for a microphone is a type of amplifier whose purpose is to amplify a weak signal to a linear level (about 0.5-1.5 volts), that is, to an acceptable value at which conventional sound power amplifiers work.

The input source of acoustic signals for a preamplifier is usually vinyl record pickups, microphones, pickups of various musical instruments. Below are three circuits of microphone amplifiers on transistors, as well as a variant of a microphone amplifier on a 4558 microcircuit. All of them can be easily assembled with your own hands.

Simple single-transistor microphone preamplifier circuit

This mic preamp circuit works with both dynamic and electret microphones.

Dynamic microphones are similar in design to loudspeakers. The acoustic wave acts on the diaphragm and on the acoustic coil attached to it. At the moment the membrane oscillates, an electric current is generated in the coil, which is under the influence of the magnetic field of a permanent magnet.

The operation of electret microphones is based on the ability of certain types of materials with an increased dielectric constant (electrets) to change the surface charge under the influence of an acoustic wave. This type Microphones differ from dynamic high input impedance.

When using an electret microphone, to bias the voltage across the microphone, set resistance R1

Since this microphone amplifier circuit is for a dynamic microphone, when using an electrodynamic microphone, its impedance should be in the range from 200 to 600 ohms. In this case, C1 must be set to 10 microfarads. If it will electrolytic capacitor, then its positive terminal must be connected to the side of the transistor.

Power is supplied from the krone battery or from a stabilized power source. Better on battery power, though, to eliminate noise. can be replaced with a domestic one. Electrolytic capacitors for a voltage of 16 volts. To prevent interference, it is necessary to connect the preamplifier to the signal source and to the amplifier input with a shielded wire. If further powerful sound amplification is needed, then an amplifier can be assembled on a microcircuit.

Microphone preamplifier with 2 transistors

The design structure of any preamplifier greatly affects its noise performance. If we take into account the fact that the high-quality radio components used in the preamplifier circuit still lead to distortions (noise) to one degree or another, then it is obvious that the only way to get a more or less high-quality microphone amplifier is to reduce the number of radio components in the circuit. An example is the following scheme of a two-stage preliminary.

WITH this option the number of blocking capacitors is minimized since the transistors are connected in a common emitter circuit. Also between the cascades there is direct connection... To stabilize the operating mode of the circuit, when the external temperature and supply voltage change, an OOS for direct current is added to the circuit.

Three-transistor electret microphone preamplifier

This is another option. The peculiarity of this amplifier circuit for a microphone is that the power supply to the preamplifier circuit is carried out through the same conductor (phantom power) through which the input signal goes.

This microphone preamplifier is designed for working together with, for example, FEM-3. The supply voltage to the microphone goes through resistance R1. The audio signal from the microphone output is fed to the VT1 base through the C1 capacitor. , consisting of the resistances R2, R3, the necessary bias is created on the basis of VT1 (approximately 0.6 V). The amplified signal from the resistor R5, which acts as a load, goes to the base of VT2, which is part of the emitter follower to VT2 and VT3.

Two additional elements are installed near the outlet connector: load resistance R6, through which the power goes, and the blocking capacitor C3, which separates the audio output signal from the supply voltage.

Microphone preamplifier on 4558 chip

The 4558 operational amplifier is available from ROHM. It is characterized as a low power and low noise amplifier. This microcircuit is used in a microphone amplifier, sound amplifiers, active filters, generators voltage controlled... The 4558 has internal phase compensation, increased input voltage threshold, high gain, and low noise. Also, this operational amplifier has short circuit protection.

(140.5 Kb, downloaded: 2485)

This is a good option for building a microphone preamplifier on a microcircuit. The mic preamp circuit is different high quality reinforcement, simplicity and does not require a lot of strapping. This microphone amplifier for dynamic microphone also works well with electret microphones.

Working with electrical appliances has always been considered difficult. Usually, only people who have enough experience or have studied this in educational institutions are engaged in it. We are used to buying equipment in specialized stores, so few people think about self-production different types devices. Of course, you can repair something yourself, but making equipment at home requires skill.

If you have the necessary equipment and materials, experience in this area and a desire to design something and save the family budget, you can try to find interesting ideas on the Internet. There you will find many interesting ideas and tips on how to make your appliances better.

In this article, we will look at one of the studio devices that can be used for personal use. It will go about microphones and how to create them with your own hands at home. We will consider all the pros and cons of this method.

IMPORTANT: Working with electronics and electrical appliances carries risks and potential health hazards. We recommend that you refrain from work if you are not confident in your skills and abilities in the field of electrical appliances.

Can I make a microphone with my own hands?

A person is able to create almost anything he wants, nature has awarded him with inimitable intelligence and the ability to fantasize. A microphone for a computer is far from the most complex device of the possible inventions of mankind. But it is worth considering the level of your abilities and skills. The final result of all work will depend on them.

If you are seriously thinking about creating a unique microphone, it is worthwhile to provide the workflow with everyone in advance. the necessary tools and materials. To do this, you need to purchase:

• To create an electret microphone, you will need a special capsule that can be pulled out of the radio or used on the market. It is he who will be the main element in creating a home microphone.
• Special adapter for connecting to a 3.5 mm jack socket. You can use the wire from old headphones with the appropriate cable.
• Any cylindrical material is quite enough for the main body: syringe tubes, cans, tubes ...
• The required amount of wire. Choose the length according to the distance from the sound transmitter. It will be optimal to use a length of 1 - 2 meters.
• Foam or fur cover that protects the case from wind and moisture.

This is enough to create a homemade version of the device. No expensive elements, only the essentials for proper functioning. This method will help you save money, since good equipment in stores is very expensive, and cheap models usually have poor parameters and characteristics of the resulting sound.

IMPORTANT: Appearance the microphone will turn out to be unusual and will differ from the store options. If you wish, you can purchase additional parts for the case or look for old non-working devices and take spare parts from them.

Manufacturing instruction

After you have prepared everything for manufacturing, you can proceed to the most difficult stage of work. Be especially careful when performing the sequence of manipulations with the electronics. For convenience, all points are detailed in the instructions below:

1. Prepare the microphone housing. Round off the previously prepared cylindrical workpiece and cut it off at the ends, leaving the edges open.
2. Thread the wire inside the cylinder and secure it inside by tying one end in a knot.
3. Now solder the capsule to the end of the wire that is inside the cylinder and secure it with a clip or paper clip. The capsule braid must be connected to the shielded wire.
4. Solder the other free end of the wire to the 3.5 mm jack plug. In this case, you should connect both channels of transmission of sound vibrations and broadcast them to the transmitter.
5. A foam cover works great for the top, cut it to the appropriate sizes and shapes and attach to the top.
6. After that, connect the device and test its operation by saying a few phrases into the microphone. At correct connection wires, the sound should be transmitted to the capsule and amplified.

IMPORTANT: If there is no result, the problem may be in the soldering points. Try disassembling everything and re-soldering the wires to the capsule and plug.

How long will a homemade microphone last?

The exact service life for homemade things, as opposed to purchased items, is difficult to determine and say. You will not have a guarantee for this product, so you will also be able to repair and extend its performance yourself. Depending on a number of factors, the term of use will also change. Among the main parameters affecting the duration of functioning are the following:

• The quality of the materials used during work.
• The security of the wire and the ability to withstand heavy loads.
• The mode of operation depending on the required parameters of the technique and the supplied voltage.
• Accuracy of use and timely troubleshooting.

Try changing the characteristics and using different materials to compare and choose the best option.