Sometimes you hear a rather unpleasant noise every time you plug in your speaker. The noise kills your mood and might even make you want to chuck that speaker into the bin.
This noise usually occurs when we connect our amplifiers to sound sources such as speakers, cellular phones, mixers, audio interfaces, and others. In this case, we reduce the amplifier’s level to reduce the obnoxious sound, which defeats the purpose of an amplifier.
Many people who purchase amplifiers are not electrical engineers or specialists who can identify the source of the problem. We occasionally check the cables to see whether they are correctly plugged in or switched off and on the device to silence the noise. It does work in some instances but not in others.
This article on how to get rid of humming noise from amplifiers will explain some of the most frequent reasons for humming noise in amplifiers and how to get rid of it.
Why Does My Amplifier Buzz?
We utilize amplifiers in high-power audio systems because of their ability to boost audio volume. If there’s a problem, they might make an unpleasant hissing sound called an amp buzz.
The most common cause of amp buzz includes an ungrounded AC power supply, ground loops, AC line noise, RF interference, cable noise, or devices such as the audio source, pedalboards, FX units, microphones, or guitars.
What Causes the Humming Noise?
The amplifier’s noise may originate from sound sources such as speakers, cell phones, music players, cable lines, or other device components. Here are some of the most prevalent reasons for humming noise in amplifiers.
● Unbalanced Input and Output Signal
When a sound source (output) has a higher signal than the amplifier, it might cause problems (input). A disbalance in the output and input signals results in a hum.
● Ground Loops
When you connect the ground (earth) pin to the main electric outlet, the current does not go down the wire meant to be its pathway but instead forms a loop and returns to the current source. To further understand this, imagine connecting an amplifier to the primary source of electric current through its earth pin or connection. If the speaker is not a Bluetooth-enabled device, you must additionally connect the speaker’s earth pin to other sources of electric current. The cable wire connecting the speaker must also connect to the amplifier.
There is a voltage differential in this situation because the two devices connected by a cable line may have different quantities of power flowing. This discrepancy generates a grounding loop in which electric current travels to a channel other than the intended wire, causing a humming noise.
● Unparalleled Signal
When the wires connecting the speaker to the amplifier do not match or transmit the same signal, it results in unparalleled signal generation. That implies that the cable we use for connections must equalize the signal. You would need to connect the high-frequency sound source to the CPU’s line input on the computer. The line input has a lower frequency to balance the two devices by keeping the frequency at a high signal. Noise is produced due to the difference in input and output signals.
● Defective Capacitors
If you’ve tried everything and the amplifier still isn’t working, it might be due to damaged capacitors or poor amplifier wiring.
● Defective or Disconnected Cables
The cables connecting the sound source and the amplifier might be the source of hums. Long-term usage of wires can cause them to wear out, resulting in a loss of sound quality.
Similarly, when the earth cable’s chassis does not link to the earth’s connections, it generates a hum. This happens if the components of the line connecting the sound source and amplifier are not properly connected.
● Poor Sound Source
There are also times when the quality of the sound sources, such as a speaker, is the issue; in this instance, modifying the sound coming from the source is the only option.
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Types of Humming Noise Coming From the Amplifier
Humming noise in the amplifier can happen due to a variety of circumstances, and there are different types of noises as well. The key to correcting the noise is identifying the type of noise. There are mainly two types of amp buzz:
● 120 HZ
Ground loops cause the amplifiers to produce 120 Hz sounds.
● 60 HZ
The majority of amplifier sounds fall into this group. 60 Hz hums are due to poor shielding, cable issues, and closeness to magnetic fields.
How to Fix Humming Noise Coming From an Amplifier?
We have discussed some of the major causes of humming noises above, and there are multiple ways to fix the problem.
● Connect a Resistor
If the misaligned signals are causing the humming noises, connect a resistor to the sound source. The capacity of the resistor should not exceed the power of the source. A resistor should be connected to the output wire cable on one end and the sound source board on the other.
● Use the Same Electric Outlet Source
When the source of the humming noise is the ground, there are several options for removing it from the amplifier. The first step is to utilize the same electric outlet source, which produces the same amount of current and maintains a voltage balance between the amplifier and the speakers.
● Check the Cables
Before using the device, you should double-check that all cable wires, connections, and tool pieces are securely fastened.
● Get High-Quality Cables
If the cables are faulty, replace the substandard cable wires with new, sturdy, and high-quality ones. You may also use ferrite chokes on the wires to reduce the frequency carried by the line.
● Connect to Isolating Transformer
Connect the ground line to an isolating transformer (adaptor) if the noise persists. An earth lift switch on the adaptor reduces the amount of electricity that passes through the cable wires.
● Connect Ground Wire From Speaker to the Amplifier
Connecting a grounding wire from the speaker to the amplifier is another option to eliminate the ground. The grounding wire offers a second way for the signal to travel, preventing ground loops and hums.
● Know Your Device
It’s critical to understand the signal carried by the cable (output) and the signal that will be received by the input. One way to avoid this is to become familiar with your device. Some cables act as adaptors or ground loop isolators, preventing a loop even if the signal difference is only potential. Different cables, such as RCA, jacks, TRS, TRRS cables, XLR, and others, should be learned. This information is beneficial and helps you save money by preventing you from contacting your gadget for repair.
● Seek Expert Help
If the capacitors are faulty and you’ve exhausted the alternatives, you might want to consider professional help.
● Change the Settings of the Digital Audio Workstation
In the case of a mixer or an audio interface that can be altered by the program, sophisticated settings in the Digital Audio Workstation can improve the sound quality.
There are times when amplifiers generate a humming noise rather than a powerful, high-definition sound. It’s quite aggravating to be in this situation.
Most of the time, the solution lies just in front of you, and you just have to find it. In certain circumstances, all you need to do is relocate your devices away from the amp or connect them to a shared ground through the same channel. This guide will allow you to successfully solve the amp buzz without having to buy a new amp, speaker, or audio source.
If you are able to troubleshoot the problem yourself, you can successfully solve it on your own.
John Fleming is the senior editor for Audiophilez.com, covering everything from headphones to smart speakers. He is a graduate of Music Production and Technology. Before Audiophilez, John began his career as a staff writer for two different magazines, where he became a skilled storyteller across different mediums. When he isn’t writing, he can be found biking, reading books, and playing the piano.