There’s a lot riding on your pots. Let’s Get to Know them.
Pots are an integral part of your guitar’s tone and setup. They can do a lot of things, like adjusting your guitar’s volume, to fine-tuning your tune. By understanding your pots a little more, you can make sure you pick the right pot for your guitar.
Which Pot to Choose? 250K or 500K?
Linear vs. Audio Taper?
We get asked about Linear and Audio Taper pots a lot. Despite choosing which resistance of pot to go with, there are two types of pot “Tapers“. Taper refers to how the swipe acts and sounds: is is smooth and gradual? Or, quick and abrupt?
Linear Pots: Linear pots are, well, linear. Imagine a straight line on a graph: electronically, your wiper and taper is just like that – a straight line. You would think that this is the end-all, be-all of pots, right? Well, the human ear doesn’t really hear that way (there’s a thing called the Weber–Fechner law). What happens? 90% of your perceived signal change is found in the first 25% of the turn. That means, you turn your pot a little bit, and the bulk of the change happens right there. Not very useful for certain applications.
Audio Taper Pots: Audio Taper pots are different from Linear pots as they are logarithmic. Imagine that straight line, only curved in the middle. The result is an exponential increase or decrease in resistance as you turn the pot. What happens? You experience a smoother change when you turn the pot. This means that you can perceive 50% loss in volume at the “5” mark!
We prefer Audio Taper Pots for Volume and Tone, but you can always experiment!
Split Shaft or Solid Shaft?
This is all about the knob! If you have plastic knobs like a Strat, those require Split Shaft – you can simply slip the plastic knobs on.
If you have Metal knobs with a set screw, those require Solid Shaft pots. For Metal knobs, you have to tighten the set screw onto the post. Consequently, this is really hard to do with a Split Shaft, and you might break part of the shaft doing so.
A quick fix is to use a “sleeve” which is a metal tube that goes over the Split Shaft, basically converting it to a Solid Shaft pot.
Volume Pot Basics:
Now that we’ve covered some of the most frequently asked questions, let’s dig into how pots work. Let’s start with the Volume Pot:
On a Volume Pot, a basic set-up is this for a Gibson®, Strat® or Tele®:
- Input = Lug 1
- Output = Lug 2
- Ground To Casing = Lug 3
The third lug connects to ground. That means, as the sweeper moves towards the grounded lug, more of your signal is sent to ground. When the pot is turned all the way counter-clockwise, all of your signal is being sent to ground, thus, no volume!
See below for an image (Please note these images are from the bottom of the pot – not the top of the guitar. When you turn your knob, it goes in the direction described below.):
In Ex B, The sweeper is moving towards the grounded lug – which means some of your signal is being sent to ground. If the sweeper was turned all the way counter clockwise, no signal would come through your amplifier.
The opposite example, Ex. C, your input and output are basically connected – zero resistance. Therefore, all of your signal is passing through the output lug. If you didn’t ground Lug 3, your volume pot won’t work correctly. It will never give you zero output. In Examples B & C, the Output Jack is being Grounded. This works for 1 Volume guitars, like a Strat or a Tele.
What if you have 2 pickups and want to turn down the individual pickups themselves?
To accomplish this, you change the order of the Lugs. Instead of Lug 1 being the input, Lug 1 is the output. The sweeper will be the Pickup itself, instead of the Output Jack. So, instead of the Output Jack being sent to Ground, the Pickup is being sent to Ground. This works well for Jazz Basses, or P-J Basses. See Below Ex. Ba and Ca for an diagram for this type of wiring:
TONE POT BASICS:
You turn your Tone Pot counter-clockwise.
Your signal starts to pass through the Tone Cap, which connects to ground. (Example D)
The Tone Cap will reject the low frequencies, allowing the high frequencies to get sent to ground, thus making your tone sound darker.
See below for an illustration:
As you can see from Ex. D and Ex. E, the tone pot works pretty similar to the regular Volume Pot. This time, we have our friendly friend the Tone Cap to help us fine-tune our tone!
What is a No-Load Pot?
Before we get into No-Load Pots, let’s talk about “Load”: The definition of Load in terms of electricity is anything in a given circuit that “consumes” energy as opposed to sourcing (providing) energy. Even on “10”, your tone pot is still “sucking up” electricity. The Sweeper (Middle Lug) is still technically on the Resistance Strip, which draws power from the Volume Pot.
On a No-Load pot, there is a break on the Resistance Strip where the wiper is taken completely out of the circuit. It’s like “no man’s land” for the wiper, so much so that the Volume Pot doesn’t “see” the No-Load Tone Pot at all – almost like it’s invisible.
So what does this do to your guitar’s tone? Well, you’ll never know until you hear it for yourself, but, it will make your pickups sound a little more “full-throttle”. They might sound a little bigger, fuller, with added bass and treble. This is all personal taste, and we can take them or leave them, depending on the guitar.
What is a Blender Pot?
Whew. Now you have a grip on the basics. I hope this article has been helpful. Now use your guru knowledge to create your own unique tonal combinations, and make sure you choose the pots that will work best for you.