Often, we encounter annoying noise that our amplifiers produce when we connect it to the sound sources, i.e., speakers, cellular phones, mixers, audio interfaces, and others. In this instance, we tend to lower the amplifier’s volume to minimize such unpleasant sound, defeating the purpose of buying an amplifier. Many of those who buy amplifiers are not electrical engineers or experts who can detect the problem’s cause. To stop that noise, sometimes we tend to check the wires if they are plugged in tightly, or we would turn off the device and turn it on again. It might work, but in some instances, it doesn’t. This article on how to remove humming noise from amplifier will provide you some common causes of humming noise from our amplifiers and offers ways to eliminate it.
What Are the Common Causes of Humming Noise?
The noise produced by the amplifier may come from the sound sources such as speakers, cellular phones, music players, cable wires, or other parts of the devices. Here are common causes of such occurrence and ways on how to remove humming noise from amplifier.
Unmatched Input And Output Signal
There are instances when a sound source (output) has a high signal than the amplifier (input). When the output and the input signals are not balanced, the amplifier produces hums.
How to troubleshoot: You need to put a resistor to the sound source. The resistor’s capacity should not exceed the source’s power. Placing a resistor connects one end of it to the output wire cable and the other end to the sound source board.
Grounding (earthing) happens when you connect the ground (earth) pin to the main electric outlet, but the current does not go through the cable that is supposed to be its pathway but creates a loop, and the current goes back to the source of the current. To illustrate more on this, say, for example, you connect an amplifier through its earth pin or the connector to the primary source of electric current. And you also connect the speaker’s earth pin to the other sources of electric current, in case the speaker is not a Bluetooth-enabled device, which makes the power to turn on. You also connect the cable wire from the speaker to the amplifier. In this case, wherein the two devices connecting through a cable wire may have different amounts of electricity flowing, that results in a voltage difference. That difference creates a loop in which electric current flows to another pathway other than the intended cable and called grounding, resulting in a humming noise.
Troubleshoot: There are many ways on how to remove humming noise from amplifier when the cause is the ground. The first thing to do is to use the same electric outlet source in which the amount of current produced is the same and ensures a balance between the amplifier and speaker’s voltage. If the noise persists, insert an isolating transformer (adaptor) to the earth cable. Adaptor has an earth lift switch that minimizes the amount of current that goes through the cable wires. Another way to eliminate the ground is to connect a grounding wire from the speaker to the amplifier. The grounding wire provides another path for the signal to flow, prevents the ground loop, and prevents hums.
Unparalleled Signal Produced and Received by Cables
Unbalanced signals occur when the cables that we connect from the speaker to the amplifier are unparalleled or do not carry the same signal. That means the cable that we use in the interconnection must equalize the signal. You should connect the sound source that carries high frequency to the computer’s CPU’s line input. Line input has a lower frequency that intends to frequency a high signal and balances the two devices. The difference between the signal of the input and the output causes annoying noise.
Troubleshoot: Knowing the signal carried by the cable (output) and the signal to be received by the input is a must. One thing to avoid such an occurrence is to get well with your device. Some cables serve as adaptors or the ground loop isolators that do not create a loop when used even if the signal’s difference is potential. One should get familiar with different cables such as RCA, jacks, TRS, TRRS cables, XLR, and others. Having this knowledge is advantageous and helps save your dollar by keeping you from consulting your device for repair.
Disconnected Earth Cables
It would also cause hum when the earth cable’s chassis is not connected to the earth connectors. When the parts of the line that connects the sound source and amplifier are not correctly attached.
Troubleshoot: Before using the device, ensure that cable wires, connectors, and all parts of the tools are correctly secured.
Amplifier’s Capacitors are Defective
When you try all troubleshooting, but the amplifier is not doing fine, it might have faulty capacitors or the amplifier’s wirings are defective.
Troubleshoot: Seek expert advice.
How to remove humming noise from amplifiers when the problem is the cable? Hums can be due to the wires connecting the sound source to the amplifier. Wires used for longer times can go to the wear-and-tear stage, thus deteriorating the sound’s quality.
Troubleshoot: Try replacing the cheap ones with new, durable, and high-quality cable wires. Or you can attach ferrite chokes on the cables in which lessens the frequency that the line carries.
Poor Sound Source’s Quality
There are also instances when the problem is the sound sources’ quality, say, a speaker.
Troubleshoot: In the Digital Audio Workstation, the sound’s quality can be enhanced through its advanced settings, in the case of a mixer or an audio interface that can be edited by the software.
We bought amplifiers to magnify the sound produced by our speakers, cellular phones, and other sound sources. Yet, there are unavoidable instances when amplifiers produced a humming noise instead of loud, high-definition sound. It is just frustrating having this experience. Thus, this article addresses such a problem and provides details on how to remove humming noise from amplifier. As there are many causes of such occurrence, there are also many ways to fix it. Know more about amplifiers.