Demystifying the science behind effects pedals
By Robert Witmeyer (Blue Skool Records)
By Robert Witmeyer (Blue Skool Records)
Music is not an exact science, it a wonderfully dynamic expression of emotion that is deeply personal and distinctly human. But music, like any artform, is also a craft. And in order to master the subtly of expression, one must also understand the tools and architecture that support the craft. Effects pedals are an essential component of a modern guitar player's sound, and understanding the nuances of your pedal board can be the difference between sounding like an pro or an amateur. In this article we will explain the various pedal jargon you will encounter in the hopes that you will be able to make sense of the overwhelming information that is thrown at players in forums and online videos. After reading this article you should have a better understanding of the individual components that make or break a pedal's tone and ultimately gain the ability to make educated decisions on what pedal to add to the valuable real estate that is your pedal board!
That said, some vintage pedals used Carbon Comp, and while less efficient components, they may contribute to the "magic" tone of a certain circuit like a Wah Wah. Resistors slow the flow of electrons, thus resisting the flow. For instance, in some circuits, higher resistance means more gain, while in others, the inverse is true. It is worth mentioning that most knobs on pedals (potentiometers or pots) are merely variable resistors that allow you to adjust a parameter by varying the resistance.
In terms of FX pedals, Capacitors, or Caps, equal tone. Bigger Cap values allow lower frequencies to pass, while the smaller values can be used to filter out noise, hiss, thizz, or even smooth out shrill frequencies. While Caps are also crucial to the power section of a pedal, in terms of mods, they are most commonly used to alter the tone range of a pedal. There are various types of caps made from myriad materials, with the most common being: ceramic, metal film, polyester film, electrolytic, and tantalum.
The most common diode everyone knows is the ubiquitous LED, or light emitting diode. An LED is what makes up most modern Christmas lights, as well as the status lights on your pedals that illuminate when you engage the effect. LEDs come in many colors and sizes, and each one has unique electrical traits. There are also other diodes including ones made from germanium and silicon. While diodes are used in the power and filter section of pedals, they are absolutely crucial for adjusting the clipping texture of a pedal. Imagine a nice smooth sine wave with equal zenith and nadir. That is the sound of your instrument visually. Now imagine the sine wave going through a diode, and the zenith and nadirs are chopped off, creating a "clipped" sound wave. The more a diode clips the signal, the more the sine wave approaches a square wave, thus giving the guitar a "buzzsaw" tone. All diodes clip the signal differently, with some slightly shaving the top (smooth tube-like overdrive), to aggressive clipping that approaches a square wave (fuzzy, buzzy goodness), and everything in between. Sometimes, pedals have a different amount of clipping on the top of a wave versus the bottom. This asymmetrical clipping will add distortion to either the higher frequencies only, or just to the lower ones, giving the wave form a lack of symmetry. As a result, asymmetrical clipping can give pedals a much more tube-like distortion.
Silicon - Most common. Can sometimes sound compressed with a mid scoop.
LED - Cool boutique option. Lets more lower mids and mids through for meaty tone, and less gain/more gain at the extremes.
Germanium - Compressed and squishy with less distortion on tap, generally speaking.
MosFet - MOSFETs are actually transistors used for the amplification section of some pedals, but boutique builders are now using them in place of the clipping diodes for a high gain, high headroom, high fidelity tone makeovers. MOSFETs are the preferred clipping diode of Blue Skool Records.
Obsessed with building and modding pedals for the past 10 years, Robert Alan Witmeyer is a local professional musician and multi-instrumentalist in the South Bay Musical Community. He received his first pedal as a gift during high school, and instantly became a pedal addict. While Witmeyer recently won the KFOX Riff Off, earning him the title of "Best (unsigned) Guitarist in the SF Bay Area", he is also proficient on 163 other instruments including piano, bass, mandolin, banjo, vibraphone, organ, and various percussion. After releasing multiple albums on itunes, amazon, spotify, etc, Robert found his live tone lacking, and began researching what big name acts did to achieve their legendary tone. Upon learning about the art of "modding", Witmeyer began altering all his pedals, and later, started building his own effects using his label name, Blue Skool Records. Throughout the years, Blue Skool worked with other companies to create unique circuits, including designing and promoting an original Fuzz and Octavia pedal, mini Amp, and other circuits for Peacekeeper Guitars at the infamous NAMM show. As a music journalist, Robert reviewed pedals for Guitar Player magazine, and was a contributing writer with pedals as his forte. Today, Blue Skool Record's stompboxes are on the boards of many local pros including Simon Santiago (the Houserockers), Rome Yamilov (Aki Kumar Band), and Jim Thomas (The Mermen).