Have you heard about octave pedals and wonder what they do? Octave pedals can beef up your tone or change it entirely in an array of exciting ways. Some octave pedals provide a little extra “oomph,” either boosting a solo or filling in some low end when there’s no bass player. Others fill out your sound in ways that mimic classic organs or 12-string guitars. And some pedals transform your guitar so much it almost becomes a synthesizer. Knowing what different octave pedals do can help you pick the best tool for your sound.
What is an octave?
At their roots, octave pedals generate one or more octaves based on the guitar note being played. To understand this, we’ll need to understand what an octave is.
Like pianos or almost any other instrument, any guitar neck consists of 12 notes that repeat in higher or lower registers. Those are:
A – A# – B – C – C# – D – D# – E – F – F# – G – G#
In standard tuning, the lowest string on a guitar is tuned to E. If you play that string without pressing any frets, it will produce an E. Playing the exact string while pressing the 12th fret will also produce an E an octave higher.
When looking at a piano keyboard, you may notice that the pattern of white and black keys repeats itself. The lowest note is A0, and as the pattern repeats, each following A would be called A1, A 2, etc.
Why are these the same note?
Musical notes represent specific sound frequencies. The open E string of a guitar resonates at about 82 Hz. The 12th fret of that exact string resonates at about 164 Hz, twice the speed as the open string. E2 is the same sound as E1, just twice as fast! These frequencies sound the same but different because they are mathematically related to each other.
Octave pedals process a single note and reproduce one or more octaves based on that note. You might play that open E string, and the octave pedal will make it sound like you’re playing the open E and the 12th fret simultaneously.
Types of octave pedals
Some pedals only produce one octave, some produce several. Sometimes the octaves go higher, sometimes lower. To understand what different octave pedals do, we need to look at the unique factors that make them different.
Monophonic octave pedals
The first octave pedals created were all monophonic. Mono means one, and phonic references sound. Therefore, monophonic means one sound.
A monophonic octave pedal can only interpret one note at a time and produce an octave based on that note. These pedals can’t process all of the notes in a chord simultaneously and can make some crazy sounds when you try. Monophonic pedals also struggle with two notes that are played too closely together.
Sometimes, though, that crazy sound is what you want! As the pedal struggles to interpret the notes being played, they can produce a very cool glitchy effect that is difficult to replicate. At the same time, the effect of pushing out only one note at a time creates a punchy effect that makes solos cut through and demand attention. Jimi Hendrix made this effect famous in songs like “Purple Haze” and “Fire” while playing through the famous Roger Mayer Octavia.
Most of these early octave pedals delivered one octave higher than the note being played on the guitar. Eventually, pedal manufacturers began to make pedals that offer an octave down. As they noticed that guitarists pushed the gain on these pedals to achieve a natural overdrive, they began to embrace that aspect as well, leading to some very interesting fuzz and octave pedals. The MXR Blue Box is a monophonic octave fuzz pedal that creates a note two octaves down for some huge fuzzy sounds.
Polyphonic octave pedals
While monophonic octave pedals deliver some sweet tones, they are almost defined by their limitations. Polyphonic pedals, on the other hand, open up the possibilities of what octave pedals can do.
Boss released the first polyphonic octave pedal, the OC-3, in 2003. The most significant innovation in this pedal was the ability to process multiple notes simultaneously to create octaves. Combined with the dual outputs it provides, it allows two-piece bands and singer-songwriters to add bass to their sound. Fast digital tracking of the notes being fed to the pedal enables it to process octaves at lightning-fast speeds, so fast guitar solos and chords never glitch out.
While many polyphonic octave pedals offer a “monophonic mode” to offer the best of both worlds, some pedals are unapologetically polyphonic. These pedals begin to redefine what an octave pedal is and are capable of almost transforming the guitar into a different instrument.
Shortly after the Boss OC-3, Electro-Harmonix released the POG, which stands for polyphonic octave generator, then later, the POG2. These pedals look almost more like synthesizers than guitar pedals, and the sound is no different.
The POG is entirely polyphonic, with no monophonic settings available, and it does polyphony very well. The POG can handle big, complex chords with no problems whatsoever, producing up to three octaves for each note with zero glitches.
Individual controls of three different octaves allow the guitarist to create a wide variety of sounds. It can sound like a traditional octave pedal, a jangly 18-string guitar, or a Hammond organ. An onboard FX section allows different tone sculpting to sound like an electric synthesizer or a string orchestra.
Octave pedals have come a long way since Jimi rocked the Octavia. They fill a wide variety of needs, from adding more punch to solos to completely transforming the guitar. Some pedals are incredibly versatile and feature monophonic and polyphonic modes, while others lean into their strengths. Knowing what they do and how they work is key to understanding which one is right for you. Once you know that, there is a pedal for just about any need or budget.
If you’re thinking about buying or upgrading your current octave pedal read our article on the Best Octave Pedal for Guitar.