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Article: Knobs the Silent killers of Potentiometers

Knobs the Silent killers of Potentiometers

Knobs the Silent killers of Potentiometers

I know what you are thinking. This is clickbait. But its not. At this time we have sold tens of thousands of kits that we worked really hard to make audibly perfect. But, we started noticing a pattern. People contacting us for customer support as their kit that left us working, is no longer functional. Now, in most cases it is due to a simple mistake like installing your pickups incorrectly. But surprisingly a decent amount of the time it's due to the customer installing a knob that is not designed for the pot.

What do we mean? 

Basically, each Pot brand uses a distinct pattern for their knobs. If it is a knurled shaft Potentiometer, you have either an 18 tooth "Coarse" Pattern or a 24 tooth "Fine" pattern.18 and 24 tooth knurled pattern

If it is a Solid shaft you have the Import 6mm, or the US spec 1/4th (6.35mm) 

 6mm and 1/4th solid shaft

Where this gets tricky is installing the wrong size can apply a ton of downward pressure on the pot shaft damaging the shaft housing and causing the internals to not touch. Making the pot non-functional or barely functioning.

 Real examples belowPhoto of two Pots damaged by knobs

Luckily, If caught early (like the pot on the right) and not severe (Pot on the Left) you can easily compress the pot back in place making it functional. But often people don't catch it and think that it is just a bad pot. 

In severe cases.

The shaft housing gets so damaged that the pot is in fact truly "broken"


So how do you know when you need new knobs? 

Well the easiest way to tell is to look at the Pot brands Specs. For us it is located in our Part Info tab on the product page. But if you don't have that information. Measure it by either

  • Counting the star pattern if it is a knurled shaft
  • Measuring the shaft itself if it is a Solid shaft.

Some examples when you should assume you will need new knobs.

  • Converting an import guitar to US spec

    • This could be as simple as taking a guitar like a Squier, or Epiphone, and installing a US spec pot. 
    • This includes MIM, and MIJ Fenders which often use "CTS" pots but are a custom 6mm version designed just for those.
  • Switching a Pot for another brand
    • Switching a CTS pot for something like Bourns, or Alpha

So to summarize this post. Be Careful when installing a knob. It just might kill your pot. 


Thanks,you taught me something important before I had to learn by breaking a pot with the wrong knob.

Curtis Ferguson

Great article, summarized well.


Well. I definitely have done this to a pot. haha


Thanks for this tidbit of great knowledge!

Robert Starr

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