How Do Volume and Tone Pots Work For Guitar?

Volume and tone pots play a crucial role in your guitar’s sound and setup. By learning more about these pots, you can ensure you choose the right type and value for your instrument.

THE BASICS OF POTS

A potentiometer, commonly referred to as a “pot,” is a type of variable resistor. By turning the knob on the pot, you change how electricity flows through it. Inside the pot is a circular resistor strip, known as the “element,” which is contacted by a component called a “sweeper.”

When you turn the knob, you adjust the position of the sweeper along the resistor strip. This adjustment allows you to select how far the electricity must travel on the strip before reaching its output.

A potentiometer functions as an “L-Pad,” an electrical device that performs two tasks simultaneously. It introduces series resistance and creates a short circuit across the signal. This short circuit helps dampen high frequencies in the signal, even when the pot is set to its maximum value, or “10.” For example, with a 250K pot, you can select any resistance value between 0 and 250K.

Internals Of A Pot

In Example A, you can see that the pot consists of a resistance strip made of resistive material and a sweeper. The sweeper moves across the resistance strip to achieve the desired level of resistance.

For a 250K pot, the resistance measured at the Start of Sweep (Lug 1) and End of Sweep (Lug 3) is approximately 250K, while the middle lug serves as the sweeper. This mechanism allows you to obtain variable resistance! It’s important to note that manufacturers have tolerances; in reality, the resistance might be around 243K.

You can verify the resistance of your pot by taking an ohm reading between the two outer lugs. The pot serves as a foundation for various applications. From volume controls to tone adjustments, let’s explore a few variations to see how we can utilize a single pot in multiple ways.

WHICH POT TO CHOOSE – 250K OR 500K?

BRASS TACKS:

Single Coil pickups and brighter-sounding pickups (think Strat, Tele) use 250K Pots.

Darker-sounding pickups (P-92, 43-Gauge Big Single, P-90’s, and Hum-Cancelling P-90’s) use 500K Pots. (Read more about choosing between 250K and 500K pots here)

WHY?

The higher resistance pot won’t send your high frequencies to ground as quickly as 250K pots do. They sound brighter and allow more high frequencies to pass through the Pot. 250K Pots will send more high frequencies to ground, making the pot sound a tad darker.

Using the correct pot value is pleasing to the ear – we don’t want muddy sounding humbuckers, or piercing single-coil pickups. So, our pots help compensate and shape the tone right from the get-go.

There are Pots in the middle – we sell 300K Pots as well, which are a little brighter-sounding than 250K pots.

LINEAR VS. AUDIO TAPER POTS

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 sweep acts and sounds. Is it 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 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 specific 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 a 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 pots – you can simply slip the plastic knobs on.

Metal knobs with a set screw 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.

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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 Volume Pots:

On a Volume Pot, a basic set-up is this for a Gibson®, Strat® or Tele®:

1. Input = Lug 1
2. Output = Lug 2
3. 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! Let’s illustrate how this works:

Volume Control For Entire Guitar

In Example B, your input and output are basically connected – zero resistance. Therefore, all of your signal is passing through the output lug.

In Example C, The sweeper moves towards the grounded lug – which means some of your signal is being sent to ground. When the sweeper is turned all the way counter-clockwise, no signal would come through your amplifier – you’ve connected “output” with ground.

Volume Control For Individual Pickups

You can easily control the individual pickup volume by changing how you wire up a Volume Pot. Les Pauls and Jazz Bass wiring configurations get wired like this:

This wiring allows you to control the volume of each individual pickup, rather than the overall volume of the guitar. To set it up, simply change the order of the lugs: make Lug 1 the output instead of the input. The sweeper will be connected to the pickup instead of the output jack. Consequently, instead of connecting the output jack to ground, you will connect the pickup to ground. This setup works particularly well for Jazz Basses or P-J Basses.

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TONE POT BASICS

A Tone Pot is essentially a standard potentiometer with a capacitor soldered to it. While it functions similarly to a volume pot, there are key differences.

Instead of sending the entire signal to the ground, the tone capacitor allows only a portion of the signal to be grounded. Tone capacitors are designed to let high frequencies pass through while resisting or rejecting low frequencies.

TONE CAP VALUES:

The value of the tone capacitor (e.g., .0025?F, .02?F, .1?F) determines the cut-off point for high frequencies. A smaller value, such as .0025?F, will allow the least amount of highs to pass through. When you roll off the tone, you’ll notice a subtle change in your high frequencies, but there’s a limit to how dark your guitar can sound.

In contrast, a higher value tone capacitor, like .1?F, will roll off more high frequencies, reaching into the high midrange. This will produce the darkest and deepest roll-off with larger value capacitors.

Combining a Tone Pot and Tone Cap

1. You turn your Tone Pot counter-clockwise.
2. Your signal starts to pass through the Tone Cap, which connects to ground. (Example D)
3. 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 the above examples, the tone pot works pretty similarly to the regular Volume Pot. This time, we have our Tone Cap to help us fine-tune our tone!

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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 Sweeper is taken completely out of the circuit. Using a No-Load Pot 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.

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WHAT IS A BLENDER POT?

Lindy has installed a Blender Pot on almost every 3-pickup guitar he owns. A Blender Pot is a type of No-Load Pot that will “Blend” between two pickups that it’s wired to.

It’s a useful mod that allows you to get a lot of tone options – like Telecaster tones out of your Strat. While the Bridge is selected, turning the Blender Pot will blend in the Neck.

To illustrate a simple installation of a blender pot, check out this wiring diagram here.

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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.