Scratchy amp pots are an inevitability when you own an amp for long enough and if it’s your first time encountering them, you’re likely to not know where to look for answers.
Well, look no further.
To fix scratchy amp pots, you’ll need to get a contact cleaner like DeOxit to spray inside the pots. It’s safe to use on electronics because it dries quickly. Once you have that, you’ll need to spray it into the pots and that will solve most of your problems.
There are a lot of causes for amp pots and they can often be prevented with simple changes to how you treat your amp.
If you’re still wondering what amp pots are, we’ll be covering not only that but how to access them and work on them in this article.
What are scratchy amp pots exactly?
Potentiometers (pots) are used to control volume and tone. A potentiometer is a three-terminal resistor with a sliding or rotating contact that forms an adjustable voltage divider that allows a change in the resistance in a circuit.
A scratchy amp pot will often produce a scratchy (hence the name), static type noise. You may also experience rough patches in the dial turn rather than the healthy smooth feel you should get.
Amp pots aren’t visible to you from your amp, they’re covered by knobs and they are the things actually controlling the volume and effects.
This video goes over how a pot works in greater detail:
What causes scratchy amp pots?
Sometimes it can be caused due to wearing down. As with anything that gets used often, pots will receive ware and tear with time.
They are generally quite resilient and take a long time to break down though.
So what else causes wear? Oxidation and dirt build up on the volume and tone controls’ carbon tracks. This has several causes:
- Storing your amp in damp/dusty conditions that have regular temperature fluctuations (like lofts or garages).
- Using your pots frequently
- Not using your pots enough
- Old amps with genuinely worn out parts
- Contamination from liquids like alcohols, cold drinks, and so on
There are a lot of small parts inside the potentiometer that can wear down with time, like the carbon conduction ring responsible for volume or tone change. But a lot of this can be fixed or replaced.
How to fix scratchy amp pots?
Generally, the problem is dirt buildup.
In this case, you’ll need a can of DeOxit or something similar. This is a blend of chemicals that clean the tracks and provide a protective conductive layer on the carbon track.
Before you start cleaning the amp, make sure you unplug it and leave it unplugged for a day or two to let the caps discharge before you open it up. You could go a step further and learn to safely discharge your amp’s filter caps to be on the safe side.
If the pots aren’t too dirty, this will often do the trick on the first spray and you’ll be good for a few years before dirt builds up again. If you’ve tried spraying into the pot multiple times and you’re still not getting any improvement, it’s better to just replace the pot.
A problem that people often have with cleaning their pots is that they don’t get the liquid right inside the pot where it needs to go. You have to make sure that you get that nozzle right into the access slot.
Often this is facing down, and there are two ways to handle this.
- You can either bend the nozzle into a hook shape which will spray the liquid up and into the slot
- Or you can remove the circuit board and turn everything upside down so that the pot access slots are facing up.
Either works, and it depends on whether you’re just cleaning one pot or going for a full service.
While spraying the DeOxit into the pot access slots, you should rotate the knobs through their full range of motion. After that, let everything dry for a few hours before you put it all back together.
Here’s a video you can follow along to.
How to prevent scratchy amp pots?
Take care of how you store your amp. Don’t store it in dusty parts of your house and don’t leave it in the garage where the temperature changes daily. If you can get a plastic cover for your amp, you could put that over it when not in use too.
Adjust the knobs every now and then. It’s not good to leave dials unturned for too long, even if you’ve set your amp to the perfect settings and you’re happy with them. Mark the position and then give the knobs a turn now and then, you’ll be glad you did.
Don’t have liquids around your amp, and especially don’t put your beer on top of your amp. In the case that you do spill something onto your amp, wipe it down immediately and if it gets onto any buttons, you may want to take time to open them up and clean them too.
Lastly, you can give your amp pots a squirt of DeOxit now and then as a form of maintenance, but eventually, they will wear down and need to be replaced.
Can scratchy pots damage your amp permanently?
It would be unwise to say that any one thing can damage your amp permanently since most parts are replaceable in any amp.
Whether fixing it would be worth it is another story for another post.
With potentiometers though, if all of them are scratchy, they may be exhibiting symptoms of a problem elsewhere. Possible causes include:
- Leaky coupling capacitors
- a Preamp tube with too much grid current
- bad grounding
Overall, a scratchy amp pot won’t be the sole cause of permanent damage to your amp. Just take care to turn them regularly and don’t be otherwise reckless around your equipment, but I don’t think I need to tell that to any musician.
Hello there, my name is Ramiro and I’ve been playing guitar for almost 20 years. I’m obsessed with everything gear-related and I thought it might be worth sharing it. From guitars, pedals, amps, and synths to studio gear and production tips, I hope you find what I post here useful, and I’ll try my best to keep it entertaining also.