How to Remove Humming Noise from Amplifier

The buzzing sound that you hear is very annoying for many people.

This is usually because the sound generator of the amplifier itself gets stuck.

Usually, it is a hum, but sometimes it can even be a buzz.

If you have a microphone attached to your amp and the microphone is not too close or they are not touching, then those two noise sources will cause those sounds.

In order to fix the sound, your amp makes use of an oscillator that sends out an audio signal at a particular frequency and amplitude depending on settings in your amp.

Causes of Humming Noise from Amplifier:

If you’ve ever heard humming coming from an amplifier and weren’t quite sure what it was, there are a few different things that could be causing the noise. First of all, the amp may actually be picking up interference from another electrical device in your house; microwaves and coffee makers produce electronic noise as part of their functions.

If this is the case, try turning those devices off to see if it helps with or cures the problem. Another cause of this noise could be that you have bad ground where the amp is plugged in.

Plugging the amp into a different outlet or ensuring that there is a proper ground connection can often cure this problem. If none of these solutions works, you may have a bad power cord or a problem with your amplifier electrical connections.

Dirty speaker:

This is probably the most commonly encountered cause of hum in amplifiers.

Dirty output caps:

These are the two tiny capacitors that sit on a board with a filter before a power amplifier section and can get dirty by interacting with other magnetic fields without a properly installed shield for protection from interference from external sources, such as speakers and other electronic equipment.

Old caps can get coated by micro-dust from vibration caused by power supplies, computers, motors etc.. The buildup of dust might cause shorts in the circuit’s components or even entire sections of the circuit to “blow” open.

Bad oscillator section:

If the output signal is developed by the oscillator is being interfered with, the result will be a bad sound from your amplifier. The oscillator section can also have damaged capacitors or other faulty components that might cause a problem in sending out a clear message to all other parts of the amp.

Dirty power supply capacitors:

These capacitors hold a very high voltage and usually consist of a stack of two or more capacitors for each channel. The power supply will be designed to work as a “reservoir” for surplus voltage and should have a professional check to find out if any of its power capacitors have been damaged due to the wrong choice of the dielectric material, exposure to higher voltages than what it was designed for or faulty manufacturing.

Unbalanced power supply or left-right channel imbalance:

If any section of your amplifier’s power supply does not work together with another part of it, there will be an imbalance that leads to interference, and the result will be a hum in your amp. Sometimes this leads to burnt channels or even entire channels that stop working without visible reasons.

How to Fix Them:

Dirty speaker:

To fix this problem, use compressed air to clean off any dust on your speaker’s surface. If there are holes in your speakers which allow sound to get out of them, then it might be necessary to take off the cover or grill which prevents sound from coming out of these holes.

Dirty output caps:

The easiest way to test if the output caps are dirty is to hook up a scope and see what’s going on using the voltage that bypasses them. If all channels show the same thing, then they’re probably fine. If one channel has an open, then the cap is not working and needs to be replaced.

Bad oscillator section:

If the oscillator section is bad, then you will need to locate it and identify it as such. You can do this by checking the output of the filter caps mentioned above, and filtering out all other influences that might be present. There should be a signal there, and if there isn’t you’re going to have to locate your problem spots and fix them.

Bad power supply capacitors:

You can test for these by using an ohmmeter to check for continuity in the circuit, or by using a scope as you did above with the output caps.

Just like the output caps, you should check for these on each channel individually and locate your problem spots and fix them. The power supply should be cleaned and capacitors replaced.

Unbalanced power supply or left-right channel imbalance:

If the imbalance is present, then you will need to locate the problem and fix it as such. The first thing to do is check for bad solder joints or other parts that could be causing the problem.

Just like the output caps, you should check for these on each channel individually and locate your problem spots and fix them. If this doesn’t work then you will need to replace the power supply which might be an extensive project unless you’re a skilled technician.

If there isn’t a problem with the power supply itself, then one of the other sections might be faulty and needs attention as well. The next step would be to try replacing components in those sections until they are all good again.

FAQ’s:

How do I stop my amp from humming?

Find the dial labelled “Gain” on your amp’s control panel and turn it counterclockwise. Keep turning the dial until you don’t hear the humming sound coming from your amp anymore. If you still hear the amp humming, then there may be an issue with the wiring or the equipment the amp plugs into.

Why does my amp keep humming?

A healthy amp is likely to make some sort of noise when idle. … Poor quality pedalboards, FX units or even guitars will feed noise into the amp that will be exponentially amplified. If the AC supply is poor or your outlet is not earthed well enough then it can create a humming or buzzing sound.

How do I stop my recording from humming?

If you can’t turn it off, try to keep your microphone at a faraway distance, as furthest as possible when you’re recording. It’s common for bright lights, fans, heaters, fridges or even AC units to produce an unwanted electrical buzzing noise. This can interfere with your recording and affect the sound of your vocals.

Why is there a buzzing sound coming from my speakers?

There are many causes for the speakers humming sound issue. One of the common reasons is the electrical ground loop. … Apart from that, the hardware issue can result in the buzzing sound from the speakers, such as your speaker being faulty. In addition, the software issue, such as driver corruption probably causes the issue.

What does a ground loop sound like?

Ground loops can appear when there are two or more devices connected to a common ground and can sound like a low-frequency hum, similar to touching the end of an instrument cable connected to an amplifier.The current that is flowing through these different ground connections can cause a 60Hz hum in your audio

Conclusion:

These tips should help you to fix the sound issues in your amplifier. The best way to determine what’s causing the buzzing or humming noise is to try using a scope and/or an oscilloscope. If it’s not a fault in your amp, then replace them and see if it makes a difference.