How to tell if amp channel is blown: 5 Definite Signs

Listening to music in the car on your way home from work or while traveling with friends can be one of life’s most enjoyable things. Sadly, like other electronic gadgets, amplifiers get damaged, and the problem is not always clear at first. 

That said, here are five definite signs that an amp channel is blown: 

  • A burnt smell of electronic components
  • Oxidized jacks and outputs 
  • A blown fuse in the amp 
  • Audible sound distortion
  • No sound at all 

This article will show you some of the most common reasons why amplifiers blow out. There are a few warning signs that you can keep in mind to prevent damage or fix it before it gets worse. 

Safety Tips

As usual, I strongly urge you to observe safety whenever you’re attempting any of the procedures highlighted in this post. Before starting, keep the following safety tips in mind:

  • Turn off your amp and disconnect it completely from the outlet before opening the outer case. 
  • Use the right equipment, like screwdrivers and cleaning fluids, to clean up and fix your amp. 
  • Avoid touching the capacitors. They store a large electric charge, enough to harm you. 
  • Go through the manufacturer’s manual. 
  • Work on a clean, dry surface. 

1. A Burnt Smell of Electronic Components

This one might not be as widely known, but you can rely on your sense of smell to identify whether everything is alright inside the amp or not. Burning electrical components give off a sharp, irritating, unique smell. 

Simply put your nose close to the channels and breathe in lightly. If something is burning within the receiver, you should be able to smell it.

Don’t do this if you’re living with a respiratory condition or have allergic reactions to smoke and dust. It’s also not a good idea to linger too much while smelling burnt channels.

It doesn’t always have to be a blown channel whenever the smell is coming from your amp. However, if you smell burning components, it’s very likely your channels are at risk, even if something else is burning. In any case, weird smells should be a reason to check on your amp immediately. 

2. Oxidized Jacks and Outputs

Oxidation in electronic devices is a silent menace that often goes unnoticed. Some jacks and amp channels develop a rusty build-up after enough time passes. Once the build-up completely covers the area that comes into contact with the jack metal, that’s when reality kicks in—no sound despite having made all the required connections. 

Oxidation on wires occurs as a result of impurities in the wire material. Impure copper wears out, which becomes noticeable when you start switching the inputs. 

To spot this rusty build-up in its early stages, always check the channels before inserting any cables into them. The oxidized parts should be rusty and reddish. They may also have a rough, noticeable texture when you insert your jacks. 

How To Fix Oxidized Jacks and Outputs

An easy way to clean an oxidized jack is to use an electrical contact cleaner. You can also clean inside the channels with steel wool.

Contact cleaner is a liquid solution designed to remove contamination from electrical contacts. It can be used on printed circuit boards and other types of contacts. The main advantage of using contact cleaner is that it poses no risk to the channels. 

Cleaning inside the channels using a steel brush or some steel wool may cause damage. Use steel brushes only as a last resort and be extremely careful.

Check out the video below on cleaning your electrical gear using contact cleaner: 

3. A Blown Fuse in the Amp

Modern electronic gadgets are equipped with fuses (small tubes with thin strands of copper wires caught between two metal caps). These tiny gadgets are positioned strategically to protect the amplifier from an excessively high voltage that could melt the rest of the circuit board components. 

Instead of the circuit board taking the heat, the thin wire strand melts down and cuts off the power. A blown fuse—or one that’s almost burning out— can lead to several issues when it completely melts down. To start, the amplifier won’t work. You won’t get any sound from any channel. 

Before you deem your amp damaged, check for a blown fuse, replace it, and turn on your device. If that doesn’t turn your amplifier back on, then it’s time for a deeper check. 

Open your amp’s casing and identify the blown fuse. Most amps come with at least one of two fuses: an inline fuse and an external fuse. Check where the power cable connects to the amplifier’s battery; there you should be able to locate a blown inline fuse. Not all amps have an external fuse, but if it has one, it should be easy to spot somewhere around the battery.

If it isn’t obvious whether a fuse is blown out, you’ll need to use a voltmeter to test the fuses. There could be more serious issues with the internal wiring that will require professional help.

4. Audible Sound Distortion

Evident distortion is not the worst kind of problem you could face with your amp—we’ll get to that later. Still, regardless of the type of amp, distorted sound is a common indicator of damage within the amp

Distortion occurs for several reasons, including interference from nearby electrical fields, power supply irregularities within the circuits, and bad speaker wires. But one reason to look at, in particular, is the loss of contact between the input wires and the channels. 

When you receive distorted sounds, it could be an indicator that the two contacts—channel and input/output wires— are not correctly connected. It could also indicate a partially blown channel that can’t make a proper connection. 

To fix the problem, eliminate all the other potential causes of distortion. You also want to avoid clipping, which happens when there’s a problem between the power supply and amp. This is what happens when you force your amp pump louder sounds than it can handle.

As exciting as it is to put your music at full blast while you’re driving, doing this frequently poses a risk for your amp and speakers. The risk is even greater when you’re listening to bass-heavy music. And don’t forget about your ears: listening to loud music in an enclosed space can lead to hearing damage in the long run.

5. No Sound at All

Getting no sound is probably the worst kind of problem you can have with your amp. If you connected everything as it should be but you still can’t get any sound, you might be facing a significant problem.

Although it’s hard to determine what exactly is stopping your amp from making any sound, some of the most common suspects are:

  • Bad grounding 
  • Damaged RCA cables 
  • Faulty power cables 
  • Damaged speakers 
  • Blown amp channels 

If you’re experiencing this issue with your amp, make sure that the cable isn’t damaged and try reconnecting.

If this doesn’t work and other causes don’t seem likely, there could be a problem with other external devices in the audio chain. This includes your music player, DVD player, gaming console, phone, or whatever you’re using as your signal source.

How Do You Know if an Amp Is Blown?

Blown amp channels are not as common as you may think. What you need to worry about is the amplifier itself. Amplifiers face tons of issues that can end up affecting their performance. 

You can know if an amp is blown by turning it on and checking the power flow with a multimeter. You can also listen to the amplifier’s performance. Clipping, distortion, and overheating are some indicators that your amp is at risk. 

Here are some of the things you need to watch out for: 

  • The amp goes into protection mode more often than usual.
  • Overall underperformance.
  • The volume keeps adjusting for no reason.

The Amp Goes Into Protection Mode More Often Than Usual

The protection mode in an amplifier is a feature designed to turn off the amplifier whenever it faces risk of damage.

Not all amplifiers have this feature. For those that do, the risk could be related to issues like irregularities in the power supply, heat management issues, extremely loud volume. But overall, these are the most common reasons why your amp may go into protection mode: 

  • Overheating 
  • Improper installation 
  • An internal error in the amp
  • Faulty or loose wires 

Protection mode saves your amp from further damage. Before assuming that your amp is blown, check if it entered into protection mode.

If your amp is going into protection mode more often than usual, it’s probably an indicator of one or more of the issues mentioned above. 

There isn’t a single fix for all issues, but you can start by doing the following:

  1. Ensure that all the wires and cables are attached correctly. 
  2. Ensure that they maintain a tight connection with the amp. 
  3. Place the amplifier in a well-ventilated place to prevent overheating. 

Overall Underperformance

Another telltale sign of an issue with your amplifier is a problem in sound quality. These problems can include: 

  • Humming 
  • Distortion 
  • Clipping 
  • Blown fuses 
  • and so much more  

Humming and distortion arise from faulty wiring and electrical interference.

To be clear: humming and distortion are not the same. Humming is a low-frequency rumble from your speakers. Distortion usually leads to mumbled sounds. Humming and distortion are both common issues for car and in-house amplifiers. 

Here are a few ways to fix these issues:

  • Check the amp is correctly installed. 
  • Only use high-quality speaker wires
  • Use high-quality audio sources. 
  • Move your amp away from other electronics. 
  • Check the gain and volume settings. 

Amplifiers are not the only possible culprits. Your speakers could also lose sound quality if they have underlying issues. Your amplifier won’t perform optimally if the speakers are of low quality or need to be fixed. Before assuming your amp is blown, check your speakers and their output quality. 

The Volume Keeps Adjusting for No Reason

Many people report this issue, and it’s easy to see why it’s so confusing. You’re relaxing while you listen to your favorite jam or watch a movie, when all of a sudden the volume goes from normal volume to extremely loud for no apparent reason. 

On most occasions, the problem is nowhere near a wiring issue, a malfunctioning channel, or a problem with the original soundtrack. The problem could be within the amp itself, but the culprit could also be your device’s automatic volume control feature. 

The automatic volume control feature is an innovative technology that lowers or raises the volume on your device based on user preferences. It offers an easy response to certain conditions such as: 

  • Surrounding noise (for example, high-speed winds) 
  • Nearby large crowds 
  • Rising and falling ambient noise 

In theory, this feature has your best interests at heart. However, if all it is doing is ruining your smooth jam, you can simply turn it off and enjoy your music without it.

Not all amplifier brands support the feature, though. If you know the issue isn’t being caused by automatic volume control, then you’re probably looking at a damaged amp.

How to Fix a Blown Channel

Fixing a blown amp channel is somewhat difficult and should be left to a professional. You are going to need: 

  • Screwdrivers. The type of screwdriver depends on the screws holding the case together. 
  • A soldering iron and wire.
  • Some new channels. These can be pulled off from an old amp or bought at an electrical shop.
  • A voltmeter.
  1. Turn off your amp and disconnect it completely from the power source.
  2. Check if any connections have been severed within the amp. Check on each channel and see if current can flow through it. 
  3. Using the screwdriver, remove all the screws and open the casing. 
  4. Check on the condition of the fuse by placing the voltmeter probes on each end of the fuse. The voltmeter should show you a positive reading, indicating that there’s a current flowing through it. Do the same for your channels and test each one, one at a time. Replace the fuses if you find any damaged ones. 
  5. Check the amp for other issues such as overheating and other blown ICs, transistors, and capacitors. Once you’re satisfied with the results, close up the amp and switch it on. 

If the problem persists, you should call for professional help.

Frequently Asked Question

Why is one channel of my amp not working?

There could be several reasons why one channel of your amp is not working. Firstly, check the cable connections from the source to the amplifier. Ensure that the cables are securely plugged in and that there are no loose connections. Sometimes a faulty cable can be the culprit, so try swapping out the cables to see if that solves the problem. Secondly, check the speaker connections. Make sure that the speaker wires are properly connected to the amplifier and that the speaker is in working condition.

If the issue still persists, it might be a problem with the internal components of the amplifier. In this case, it is advisable to consult a professional technician or bring the amp to a service center for repair. It is also worth noting that some amplifiers have a built-in protection circuit that shuts off the faulty channel to prevent further damage. If this is the case, resetting the amplifier or checking its manual for troubleshooting steps may be helpful. 

How do I test an amp channel with a multimeter?

Testing an amp channel using a multimeter is a relatively simple process. First, ensure that the amp is turned off and unplugged from any power source.

Next, locate the speaker wires that connect to the specific channel you wish to test. Disconnect these wires from the amplifier. Set your multimeter to measure resistance (ohms) and touch the probes to the bare ends of the speaker wires. A functioning channel should produce a reading close to the impedance rating of the speakers connected to it. If the multimeter displays an open or infinite reading, there may be an issue with the channel or the speaker wiring.

Conversely, a reading of zero resistance may indicate a short circuit. It is also helpful to compare the readings of the channel being tested with those of a known working channel to identify any discrepancies. Properly testing an amp channel with a multimeter can help troubleshoot issues and ensure optimal performance. 

What does a blown amp sound like?

A blown amp will produce distorted and muffled sounds, lacking clarity and definition. It may also emit crackling noises, pops, or buzzing sounds. The audio coming from the speakers will often be accompanied by unwanted feedback or ringing, making it difficult to distinguish individual notes or instruments. In some cases, a blown amp may have a noticeable decrease in overall volume, with a weakened and thin sound.

Additionally, there might be noticeable signal loss or intermittent interruptions in the sound. It is worth noting that different types of amplifiers or musical instruments may have varying characteristics when they blow. However, in general, a blown amp will exhibit a significant degradation in the quality of sound and may even produce a harsh and unpleasant tone that can be easily distinguished from a properly functioning amplifier. 

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