How to Fix Amplifier Buzzing Noise Quickly

Norvan Martin

 Amplifiers are used in powerful audio setups because of their unmatched ability to increase audio power.

However, they can produce an unpleasant hissing sound known as an amp buzz if there’s an issue. 

This scares many music lovers, especially those concerned that they can’t fix it. Let’s see what causes amp buzz, how to fix it with ease, and more.

Amplifier buzzing is normally caused by an ungrounded AC power supply, ground loops, AC line noise, RF interference,  cable noise, or from devices such as the audio source, pedalboards, FX units, microphones, or guitars.

Let’s delve into more details about how to fix your amplifier’s buzzing noise. 

Why Does an Amplifier Buzz?

An amplifier buzzing sound usually originates from issues such as:

  • Ungrounded AC power supply
  • Ground loops
  • AC line noise
  • RF interference
  • Cable noise
  • Other devices like the audio source, pedalboards, FX units, microphones, or guitars

The silver lining? All these issues can be rectified.

Step-by-Step Guide to Fixing Buzzing Noise

1. Check for Ground Loop (Most Common)

A ground loop is the number one cause of amp buzz, and it occurs when audio devices are connected through different paths to a common ground. The issue with this is that it creates a single-loop antenna that is susceptible to noise via electromagnetic induction.amplifier ground loop causing buzzing

This occurs when different audio equipment receives an uneven power supply.

For example, if you plug your amp and your sound source into different electrical outlets, a ground loop is likely to occur.

Indicators of a ground loop include:

  • A loud buzz or hum through the speakers
  • Scrolling bands on a TV screen if connected

How To Fix Your Ground Loop Issue

Use a Single Power Source: To fix ground loop issues, you need to remove the loop. The easiest way to do so is to power everything through a single AC socket, as shown below:fix amplifier ground loop by using a single outlet

Use A Hum Eliminator: You can buy a hum eliminator, such as Ebtech’s Hum X, to eliminate hum. However, some of these devices actually remove the ground connection, so you should be careful. 

Remove Third Power Prong (Ground): Many people will tell you that you can also remove the third prong (ground prong) from your amplifier. While this might fix the problem, it is a shock hazard, and you SHOULD NOT DO IT unless you know what you are doing.

2. Check for Amp Input Picking Up AC Electrical Power Noise

(Please note this is NOT APPLICABLE FOR BATTERY SYSTEMS)

It’s perfectly normal for power lines to radiate some AC. When an amplifier is highly sensitive, and its feeding wiring isn’t adequately shielded, it can lead to concerns.

interference speaker static

  • Low AC radiation might produce a subtle buzzing sound that might not be bothersome.
  • However, depending on the amount of AC the amp picks up, the buzzing can significantly compromise the quality of your music-listening experience.
  • It’s worth noting that effective shielding doesn’t guarantee immunity from AC pickup. Hence, there’s no universal solution. We’ll delve into potential solutions shortly.

Note: For battery-run installations, AC pickup concerns are irrelevant as the problem doesn’t manifest. Batteries utilize DC electrical power, not AC.
AC Induction Devices: In other cases, AC induction devices (devices with motors) can cause interference. Typical examples include hairdryers and blenders. Some less obvious examples are light dimmers and failing fluorescent fixtures.

3. Fix Bad Amp Power Supply (Normally for Old Devices)

Amps’ filter capacitors can dry out over time, limiting their efficiency. So, if your amplifier has been in use for many years, the inefficiency of these components might cause the buzzing noise. They are designed to supply the required amount of power to the amp.

4. Other Causes of Amplifier Buzz

Worn-out Power Cord or Outlet: Those that are worn out and can’t grip are common causes of buzzing noise.

Outlet Polarity: If the outlet is wired backward, it could cause disturbing noise.

Signal Interference: Appliances like fluorescent lamps and light dimmers can cause hums if they share a common ground or the same circuit in home theater equipment. Magnetic fields can also interfere with the transmission of signals, resulting in amp buzz.

Types of Amp Buzz

As we’ve seen, there are plenty of factors that can cause amp buzz. If you want to fix the noise, you must start by troubleshooting for the type of noise.

The amp buzz we’ve discussed above is classified into two categories. These are:

  • 120 HZ Buzz: The 120Hz buzz refers to amp noises that ground loops cause.
  • 60Hz Hum: Most of the amp noises fall under this category. Poor shielding, cable problems, and proximity to magnetic fields are categorized as 60Hz hums.

How to Fix Amplifier Buzzing Noise

Once you determine the underlying cause of the amplifier buzz, you can fix it with ease. Here are basic ways to troubleshoot and fix the various types of amp buzz:

1. Isolate the Problem

Since no single method can fix all the underlying causes of amp buzz, it’s essential to begin by identifying and isolating the issue. Ignoring this crucial step can lead to multiple challenges:

  • Spend too much time trying to identify the problem.
  • Potentially create more complex problems.
  • Use excessive energy.
  • Fail to achieve your goals.

For the best results, approach the problem methodically. Prioritize isolating the root cause before attempting various solutions. Here are some steps you can take:

  1. Run the amplifier’s input source selection through its settings.
  2. Disconnect your speakers one by one to determine if one of them is producing the noise.
  3. Replace your cables to check if the noise is eliminated.

If every component is buzzing, it’s worth examining if your amp’s power supply is functioning correctly. Moreover, for older amps, the filter capacitors might have dried out. In such cases, consulting an expert technician is advisable.

2. Check Ground Connections

  • If you suspect a ground loop, turn off the audio system and use a heavy-duty power strip to connect the amp and the other audio sources to the same outlet.
  • Connect the ground wire of the audio source to the grounding screw, and if you can still detect the buzz, move on to the next step.
  • If you’re looking for the easiest and most common solution, you’ll find that adding a Cable TV ground isolator is suitable for your needs. It will ensure a flat frequency response, delivering an exceptional outcome.

3. Increase the Distance Between the Amp and Other Cellular and Fluorescent Devices

As noted earlier, these devices can interfere with your sound system’s normal functioning. They can create electronic fields that hinder the efficient transmission of electrical signals.

Others can also amplify AC radiation. Move your phone, fluorescent/neon lights, and switches away from the amp. If they are the culprits, the noise will disappear after doing this.

4. Condition Power

Use a power conditioner to eliminate unwanted power that can cause noise. This is especially true if you are pushing a large amp like a 2000 watt amp or even a 3000-watt amp. Advanced technologies filter electric power and ensure you get quality sound irrespective of the power source.

Here are some good power conditioners:

It would be best to use quality, well-shielded power, and amp cables on the same note. This is the standard way to reduce AC radiation.

However, you should complement it with quality cables, proper wiring, an adequate power supply, and so on.

Conclusion

Now you can see that if your audio system produces a buzz that won’t go away, you don’t have to buy a new amp, speaker, or audio source.

You can diagnose and troubleshoot the cause. In some cases, you’ll find that all you need to do is move your devices away from the amp or connect them through the same path to a common ground.

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Norvan Martin is the founder of BoomSpeaker.com. He is a professional Electronics Engineer and is passionate about home theater systems and AV electronics. BoomSpeaker was created as an online hub to share his knowledge and experiences as it relates to home theaters and home audio electronics. My email: [email protected]  Connect on Pinterest and Linkedin