My stereo amp buzzed what s going on

It can be broadly divided into electromagnetic interference, mechanical noise, and thermal noise.

1.Electromagnetic interference can be mainly divided into power transformer interference and stray electromagnetic wave interference. Generally speaking, the power transformer interference is caused by the power leakage of the multi-** speaker, and the effect of installing a shielding cover for the transformer is better if conditions permit, which can block the magnetic leakage to the greatest extent, and the shielding cover can only be made of iron materials.

In addition, using an external transformer is also a good solution.

2.Stray electromagnetic interference is common. Loudspeaker wires, crossovers, wireless devices, or computer hosts can all be sources of interference.

Keep the main speaker as far away from the computer as possible and reduce the number of peripheral wireless devices. Mechanical noise is specific to active loudspeakers. During the working process of the power transformer, the core vibration caused by the alternating magnetic field will produce mechanical noise.

In addition, a rubber shock absorber can be added between the transformer and the fixing plate.

3.The contact between the metal brush and the diaphragm is poor due to dust accumulation and abrasion, and noise is generated when it rotates. If the screws of the speaker are not tightened, and the inverter is not handled properly, mechanical noise will also be generated when the **big dynamic**.

This thermal noise can be dealt with by replacing low-noise components or by reducing the workload of the components. In addition, reducing the operating temperature is also one of the most effective methods.

4.Some computer speakers will also make noise when the volume is turned up too much. This situation is caused by the fact that the output power of the power amplifier may be small, and it cannot avoid the large dynamic peak signal at the moment, or because of the overload distortion of the horn.

This sound is called an exchange sound. You unplug all the input sockets, and then short-circuit the inputs, see if there is still one? If not, it means that the input cable or plug is not in good contact, or the sound source is not clean; If there are still any, the main reasons may be as follows:

1. Defects in circuit design 2. The components of the power supply part of the power amplifier are aging and deteriorating (especially with iron core transformers). 3. Place too close to other AC power sources (interference sources).

The main reasons for the sound to hum when turned on are: electromagnetic interference, mechanical noise, heat dryness, and other reasons.

Specific reasons: 1. Electromagnetic interference, mainly including power transformer interference and stray electromagnetic wave interference.

1. Power transformer interference.

Magnetic flux leakage from the power supply can be blocked by adding a shield made of iron material to the transformer, or an external transformer can be used. The most fundamental thing is to choose products with big brands and solid materials.

2. Stray electromagnetic wave interference.

Stray electromagnetic interference is relatively common, computer host, speaker wire, crossover, wireless equipment may become the source of interference of the speaker, if conditions permit, the main chassis should be kept away from the computer host, mobile phones and other electronic equipment as far as possible.

2. Mechanical noise.

This noise is unique to active speakers, similar to the hum emitted by fluorescent lamp ballasts, and is caused by the core vibration caused by the alternating magnetic field when the power transformer is working, and a rubber damping layer can be added between the transformer and the fixed plate.

3. Thermal noise. Over time, dust accumulation and abrasion between the potentiometer's metal brush and the diaphragm can cause poor contact and resulting noise. In addition, if the screws are not tightened and the inverted tube is not handled properly, mechanical noise will also be generated during the **large dynamic**.

How to deal with heat dryness? This can be solved by replacing low-noise components, reducing component workload, and lowering operating temperatures. For example, to reduce the working load of the component, when the volume is adjusted too much, due to the small output power of the power amplifier of the speaker itself, it cannot avoid the large dynamic peak signal of the first moment, and there will be noise, and as long as the volume is turned down, there will be no noise.

Fourth, other causes of noise.

1. The card is not inserted correctly.

It is very common for the sound card to be not tightly separated from the motherboard expansion slot, as long as the sound card is plugged in.

2. The line input is false.

Active speakers, whether they are channels or channels, have line input signal lines from the sound source to the speaker, if this line is not connected, it may cause noise. In addition, some sound cards have only one output, which is both line-out and speaker, and the acquiescence mode is often speaker, so you need to adjust the jumper.

3. Sound card driver problem.

The sound card driver that comes with the system may not be compatible or there may be a problem with the driver. If so, you can reinstall or replace the sound card driver.

5. The speaker is damaged.

No matter what kind of speaker, it will deteriorate and damage after a long time, and there will be noise if the damaged speaker continues to be used. If the noise is really caused by this reason, send it for repair or replacement.

Common solutions to electrical box noise:

1. Choose a big brand audio with enough materials;

2. Try to reduce electromagnetic interference, arrange the wiring reasonably, and stay away from radiation interference equipment such as mobile phones, radio receivers, and high-emission conformators;

3. The signal line is solid;

4. Keep the audio equipment clean and clean to reduce dust and wear. <>

The first thing to do is to find out the reason for the buzz:

One is that the external signal has a buzzing sound. The performance is gone after the input signal is disconnected. Once the input signal is connected, there you have it.

The second is caused by electromagnetic interference. It is manifested in the fact that it is weak or no longer when it is far away from the interference source (such as the main computer computer, etc.). Closer to the source of the interference, it gets bigger.

The third is caused by the power supply of the audio (mainly the audio powered by 220V). This is usually due to a failure of the filter capacitor of the power supply, and a replacement will solve the problem. Of course, when the power is supplied with direct current, there will be no humming sound.

After finding the cause, we can do it.

In addition to the problem caused by the aging and open circuit of the audio line, it should be a problem of the power amplifier circuit, such as abnormal performance of the power rectifier bridge or filter capacitor, poor grounding of the circuit board, virtual soldering of a certain component, etc.

The AC sound of the amplifier generally has a humming sound of 50 Hz and other interference sounds, which are all annoying noises that affect the sound quality of the amplifier. Generally, a good amplifier is free of these noises.

To eliminate noise, the first step is to find the noise, which is internal and external.

1.Check the external causes first. First, remove the external microphone and remove the external sound source.

Slowly turn the amplifier volume knob to see if you hear any noise, if there is an in-camera noise, that is, the noise generated by the amplifier itself, this noise can be 50 Hz AC sound, or it may be a silk sound and rustling sound. These noises are caused by poor components of the amplifier circuit itself or electromagnetic interference.

AC sound of 50 Hz is generally poor power filtering. It can check whether the filter capacitor in the rectifier circuit fails and deteriorates, and if the capacitor can be eliminated by replacing it with a good capacitor, it is generated by the rectifier circuit.

If it is not the 50 Hz interference generated by the rectifier circuit, it is the electromagnetic interference introduced in the circuit. At this time, the inspection is much more complicated, to check from the front end of the amplification circuit, first short circuit the first level of input, check whether there is 50 Hz AC sound, if not, then 50 Hz AC sound is from the first stage of entry, then to check the grounding and input interface of the first stage, input line and so on where there may be interference input. This examination should not be difficult.

The internal noise is difficult to remove, which is generally a problem of device quality, especially the internal noise of the preamplifier, which requires a low-noise amplifier and a low operating temperature.

External noise is mainly found in the sound source, input cable, poor grounding, etc. It is also generally easy to remove.

1. Communication sound. Turn on the speaker, and turn off the volume potentiometer to the end to the silent state, at this time the speaker continues to hum, first check whether the four rectifier diodes in the power supply circuit are intact, if they are intact, it means that the power amplifier circuit in the power filter capacitor leakage, the capacity is too small, desoldering, should replace the same type of capacitor, or increase the filter capacity.

Sogou asked. 2. As the volume increases, the hum also increases, which means that the noise is in the pre-amp, first of all, unplug the audio source input connection, and then turn the volume up, if there is no more, it is the problem of the audio input shielding wire, repair or replacement.

3. After unplugging the audio cable, there is a buzzing sound, which means that the voltage amplification circuit of the pre-amplifier is faulty and needs to be repaired by the master.

Listen carefully, whether it is the vibration sound of the transformer.

The buzzing sound may be due to electromagnetic interference, and the power transformer interference caused by the leakage of the audio power supply.

On the issue of abnormal noise, it is difficult to distinguish which ones are fault abnormal noises and which ones are reasonable abnormal noises. Only nearly 20% of the vehicles that went to the repair shop to detect abnormal noises really had problems. In the case of a turbocharged engine, there is a must be a difference between the sound and the sound of a naturally aspirated engine; Models with engine guards may also make noises due to friction; After some car owners come into contact with different cars, it is likely that due to their lack of understanding of mechanical knowledge, they mistake reasonable abnormal noise as a vehicle failure.

Therefore, learn to distinguish the abnormal noise of the car and avoid wasting time and energy.

The identification of car noise is limited, and it is difficult to use special instruments to measure the sound of the car, and the sound of the car can only be described and compared with the judgment of the sound in daily life. For example, the "rattle" sound caused by the dry friction of the bearing, and the "click" sound similar to the small hammer hitting the cement floor caused by the excessive valve clearance.

1. Correctly distinguish between normal and abnormal sounds.

The vibration of each mechanism in the work of the car will emit a variety of sounds, but the sound does not mean that the car is faulty, in order to avoid unnecessary disassembly, we must first distinguish between normal sound and abnormal noise. The normal vibration sound of each system component (such as the noise on the surface of the engine), the impact sound of the gear when shifting, the air intake sound and exhaust sound of using gas as the working source, and the gear meshing noise are all normal sounds. Abnormal noise (abnormal noise) can be divided into slight noise, general noise and malignant noise according to the impact on the performance of the car.

Slight noise, such as the flashover sound of high-voltage electric leakage, the slight loose sound of rolling bearings, etc., the general volume is small, the degree of wear of the parts is not large, and there is no significant change for a long time, and this kind of fault can still maintain the normal operation of the car without repair.

3. When diagnosing abnormal noise, attention should be paid to creating good auscultation conditions, and trying to eliminate the interference of other noises, so as not to affect the accuracy of judgment.

It is best to consciously amplify or reduce the sound, that is, use a screw or other metal rod as a stethoscope instrument to contact the sound part to amplify the sound, or use a single cylinder fire off to reduce the sound to meet the needs of diagnosis. The auscultation site should be kept quiet to minimize human interference.

The sound subwoofer has a humming sound that can be eliminated by:

1. Check the hum **: turn off the volume potentiometer, there is still a hum at this time, which is the reason for the power supply, measure whether the four rectifier diodes are intact (the rectifier diode and the filter capacitor in the red circle), and then check whether the filter capacitor is normal, and see if the filter capacitor is invalid and in poor contact. The power supply circuit is shown in the figure

2. The humming sound changes with the volume, check whether the grounding end of the audio cable falls off or has poor contact, and twist the audio cable twice.

3. When the sound source and audio cable are well connected, and the hum increases with the volume adjustment, it means that the telecom open voltage amplification circuit in the front stage of the power amplifier is faulty, and it needs to be eliminated by professionals.