There are many tales told of where tone originates. Perhaps it lives in the fingers, or blooms from tone woods, or emerges from pickups. And that’s to say nothing at all about pedal or amp choice. While there is some truth to all of these elements, few recognize the simplest tone sculpting tools that are always on hand yet seldom discussed: your onboard pots.
This week on TPS, Dan & Mick hosted Simon Jarrett, the brain behind Kingsley amplifiers and effects. While the episode pedalboard was loaded with more than a few Kingsley staples, such as the Constable and Squire, as well as a potential prototype pedal, temporarily dubbed the “Architect,” much of the conversation centered around the incredible power of the humble tone pot.
To get mobilize some of this knowledge for your own playing, we’ve distilled Simon’s masterclass into a crash course of must-know info on tone pots.
Building Your Tonal Lexicon
Before we delve into the details, it’s important to have a handle on some basic terminology introduced by Simon in the episode. Half of the battle in understanding the tonal impact of your pots is learning the jargon for what they’re actually doing with your signal. So here is a rundown of key terms in the conversation that you can also use to impress your bandmates and/or a prospective romantic partner.
Capacitance: This refers to the ability of a system or circuit to store an electric charge. One of the clearest examples of variations in capacitance with guitar gear is your patch cable. As Dan noted, longer cables have more capacitance which generally contributes to duller tones.
Inductance: Your pickup is a passive electronic device that generates its sound and current by an electro-magnetic field. By nature its makeup includes an inductor. Inductance, then, refers to how the pickup causes an electromotive force to be generated by a change in the current flowing.
Resistance: As the term suggests, resistance refers to the opposition that any substance or component offers when it handles the flow of a current.
Capacitors: These are any items that accumulate an internal balance of an electric charge and, therefore, store energy generated by an electric field. In the context of guitar pots, these come with varying values.
Resonant Peak: This refers to the frequency. As Simon described, guitar pickups have a largely flat output in the low and mid frequencies, which then spike and drop off quickly in the high-end. To give this some comparative context, speakers typically have an inverse resonant peak with greater spikes in the lower end.
The Anatomy of a Tone Pot
Few of us give serious thought to pots when buying a guitar. Yet their value and construction has a huge impact on the instrument’s tone. This is particularly the case with your tone pot, or pots depending on the instrument. So what do you need to know about how they’re built and behave?
First, a tone pot is simply a low-pass filter. In simplest terms, this filter controls the shape of your signal by determining the amount of low-frequency sounds that are allowed through. Think of this in terms of resistance: the tone pot’s job is to be the bouncer for your signal, when you turn it down it’s letting more low-frequencies through which we might equate with darker or duller tones.
Second, if you’re confounded by the values assigned to tone pots, there are really two things you need to know. The number assigned to the pot refers to the frequency range. As the cap decreases, the minimum tone knob setting gets less dark. While early guitar designs had pots with quite large capacitance values, generally these shrunk over time to some standard options which made it easier to dial in the sweet spots.
Third, as Simon summed up, if your off-the-shelf Strat or Tele has a bit of a glassy sound due to the “inherent brightness of the guitar,” you can tame that by either understanding how your tone pots work or even swapping them out for a different value. While your volume pot typically sees more intentional use for tidying up your tone with gain stages, perhaps it’s time to revisit its tonal neighbor and see what you’ve been missing by leaving it alone.
TPS Episode Rig Rundown:
Guitars: Fender American Vintage ’62 Stratocaster, Gibson Custom 1958 Les Paul Standard, Gibson Memphis 1958 ES-335.
Pedals: TC Electronic PolyTune 2 Mini, Kingsley Surf Prototype, Ibanez TS808 Tube Screamer Keeley Mod, Kingsley Architect Prototype, Kingsley Squire EF86, Kingsley Constable V2, Electro-Harmonix Memory Man Deluxe 1100-TT, Catalinbread Topanga Reverb.
Amps: Two Rock Classic Reverb Signature with 212 cabinet / TR65B speakers, Fryette Power Station with Two Rock 112 cabinet / WGS12L speaker.