There’s a lot riding on your pots. Let’s Get to Know them.
From turning down your volume and fine-tuning your tone, to coil-tapping your humbucker, pots are an integral part of your guitar. By understanding potentiometers, or, “pots” (for brevity’s sake) a little more, you can make sure you pick the right pot for your guitar.
A pot is basically a variable resistor. By turning the pot, you are changing the way electricity flows through it. Inside the pot, there is a circular resistor strip, or “element” that gets wiped by a “sweeper”. Turning the pot changes the position of the sweeper on the resistor strip, allowing you to choose how far the electricity has to travel on the strip until it reaches it’s output.
A Pot is used as an L Pad, which is doing two things at once: it’s introducing Series Resistance and a Short across the signal. The Short is what dampens the high frequencies of the signal, even when the pot is on “10”. (See below for comparing 250K and 500K pots.)
For instance, if you have a 250K pot, the entire resistance of the pot itself is 250K, however, by using the “sweeper”, you can choose any value from 0 – 250K.
To illustrate this further, take a look at the diagram below:
As you can see in Ex. A, the pot has a Resistance Strip, made of resistance material, and a sweeper. The sweeper will sweep across the resistor strip to achieve the resistance you want. For a 250K pot, the resistance of the Start of Sweep (Lug 1) and End of Sweep (Lug 3) is roughly 250K (manufacturers have tolerances – in reality, it might be something like 243K.) You can check the resistance of your pot by taking an ohm reading of the two outside lugs.
The Middle lug is the sweeper. This is how you get your variable resistance!
This is the foundation for all the possibilities you can achieve – from volume pots, to tone pots – let’s check out a few variations to see how we get multiple uses from one pot:
Which Pot to Choose? 250K or 500K?
Single Coil pickups and brighter-sounding pickups (think Strat, Tele) with the exception of P-90’s use 250K Pots.
Darker-sounding pickups (P-92, 43-Gauge Big Single, P-90’s, and Hum-Cancelling P-90’s) mostly use 500K Pots.
The higher resistance pot won’t send your high frequencies to ground as easily 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. This is pleasing to the ear – we don’t want muddy sounding humbuckers, and we don’t want piercing single coil pickups, so, our pots help compensate and shape the tone right from the get-go. Also realize there are pots in the middle – we sell 300K pots as well, which are slightly brighter than 250K pots.
Note: Lindy always says: “The correct pot is the one that sounds the best”. Use your ears! You might like 500K pots on your single-coils, depending on what you are trying to achieve.
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. 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®:
- Lug 1 = Input
- Lug 2 = Output
- Lug 3 = Ground
The third lug is grounded. 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:
A Tone Pot is nothing but a regular pot, with a capacitor soldered to it. A Tone Pot will work basically the same way as a Volume Pot, but just a little different.
Instead of sending the entire signal to ground, the tone cap helps by sending only a part of the signal to ground. Tone caps only let high frequencies pass through it – they resist, or reject low frequencies.
The value of the tone cap (.0025mfd, .02mfd, .1mfd, etc.) will determine the cut-off point for the highs. A smaller value (.0025mfd) will pass the least amount of highs. When rolled off, you will notice a subtle change in your high frequencies – you can only get your guitar to sound so dark. A higher value of tone cap (.1mfd) will roll off the most amount of highs, getting into your high mids. You will get the darkest and deepest roll-off with higher value caps.
Okay – now we get the gist of Tone Caps, here’s how it all comes together:
- You turn your Tone Pot counter-clockwise.
- Your signal starts to pass through the Tone Cap, which is grounded. (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. Take your Tone pot for instance: even if your Tone pot is on “10” (Clockwise) and the pot is not engaged, it is still “sucking up” some of the 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?
Blender Pots are used here on almost all of Lindy’s 3-pickup guitars. A Blender Pot is a type of No-Load Pot will “Blend” between two pickups that it’s wired to. Another way to describe a Blender Pot is a “Gradual On / Off Switch”. When the Pot is on “10”, the Blender Pot is out of the circuit.
For instance, think about a Strat with a 5-Way Switch: You have the 5.) Neck Only position, the 4.) Neck and Middle, the 3.) Middle Only, the 2.) Middle and Bridge, and the 1.) Bridge Only. If you were to wire the Blender Pot up to your Neck and Bridge lugs on your switch, then theoretically, you can get a multitude of pickup combinations.
On your Bridge (Position 1), turning the Blender Pot will roll in volume of the Neck Pickup. The same applies for the Neck Only position – it will roll in the Bridge. On Positions 2 & 4, you can roll either the Neck or Bridge in, getting all 3 pickups on at the same time.
To illustrate a simple installation of a blender pot, check out this wiring diagram here.
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.