Electronic Tuner: What Is It And How Does It Work

by Joost Nusselder | Updated on:  May 24, 2022

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If you’re just starting out on your guitar journey, you might be wondering what an electronic tuner is and how it works. An electronic tuner is a device that detects and displays the pitch of musical notes.

It’s an invaluable tool for any musician as it allows you to quickly and easily tune your instrument so you can keep playing without interruption.

So in this article, I’ll dive deeper into how they work.

What are electronic tuners

Tuning Up with an Electronic Tuner

What is an Electronic Tuner?

An electronic tuner is a nifty device that helps you tune your musical instruments with ease. It detects and displays the pitch of the notes you play, and gives you a visual indication of whether the pitch is too high, too low, or just right. You can get pocket-sized tuners, or even apps that turn your smartphone into a tuner. And if you need something more precise, there are even strobe tuners that use light and a spinning wheel to give you the most accurate tuning possible.

Types of Electronic Tuners

  • Regular needle, LCD and LED display tuners: These are the most common types of tuners, and they come in all shapes and sizes. They detect and display tuning for a single pitch, or for a small number of pitches.
  • Strobe tuners: These are the most accurate tuners, and they use a light and a spinning wheel to detect pitch. They’re expensive and delicate, so they’re mainly used by professional instrument makers and repair experts.
  • Bell tuning: This is a type of tuning that uses a bell to detect pitch. It’s used mainly by piano tuners, and it’s very accurate.

Tuners for the Regular Folk

Electric Instruments

Regular electronic tuners come with all the bells and whistles – an input jack for electric instruments (usually a 1⁄4-inch patch cord input), a microphone, or a clip-on sensor (e.g., a piezoelectric pickup) or some combination of these inputs. Pitch detection circuitry drives some type of display (an analog needle, an LCD simulated image of a needle, LED lights, or a spinning translucent disk illuminated by a strobing backlight).

Stompbox Format

Some rock and pop guitarists and bassists use “stompbox” format electronic tuners that route the electric signal for the instrument through the unit via a 1⁄4-inch patch cable. These pedal-style tuners usually have an output so that the signal can be plugged into an amplifier.

Frequency Components

Most musical instruments generate a fairly complex waveform with multiple related frequency components. The fundamental frequency is the pitch of the note. Additional “harmonics” (also called “partials” or “overtones”) give each instrument its characteristic timbre. As well, this waveform changes during the duration of a note.

Accuracy and Noise

This means that for non-strobe tuners to be accurate, the tuner must process a number of cycles and use the pitch average to drive its display. Background noise from other musicians or harmonic overtones from the musical instrument can impede the electronic tuner from “locking” onto the input frequency. This is why the needle or display on regular electronic tuners tends to waver when a pitch is played. Small movements of the needle, or LED, usually represent a tuning error of 1 cent. The typical accuracy of these types of tuners is around ±3 cents. Some inexpensive LED tuners may drift by as much as ±9 cents.

Clip-on Tuners

“Clip-on” tuners typically attach to instruments with a spring-loaded clip that has a built-in contact microphone. Clipped onto a guitar headstock or violin scroll, these sense pitch even in loud environments, for example when other people are tuning.

Built-in Tuners

Some guitar tuners fit into the instrument itself. Typical of these are the Sabine AX3000 and the “NTune” device. The NTune consists of a switching potentiometer, a wiring harness, illuminated plastic display disc, a circuit board and a battery holder. The unit installs in place of an electric guitar’s existing volume knob control. The unit functions as a regular volume knob when not in tuner mode. To operate the tuner, the player pulls the volume knob up. The tuner disconnects the guitar’s output so the tuning process is not amplified. The lights on the illuminated ring, under the volume knob, indicate the note being tuned. When the note is in tune a green “in tune” indicator light illuminates. After tuning is complete the musician pushes the volume knob back down, disconnecting the tuner from the circuit and re-connecting the pickups to the output jack.

Robot Guitar

Gibson guitars released a guitar model in 2008 called the Robot Guitar—a customized version of either the Les Paul or SG model. The guitar is fitted with a special tailpiece with in-built sensors that pick up the frequency of the strings. An illuminated control knob selects different tunings. Motorized tuning machines on the headstock automatically tune the guitar by its tuning pegs. In “intonation” mode, the device displays how much adjustment the bridge requires with a system of flashing LEDs on the control knob.

Strobe Tuners: A Funky Way to Tune Your Guitar

What are Strobe Tuners?

Strobe tuners have been around since the 1930s, and they’re known for their accuracy and fragility. They’re not the most portable, but recently, handheld strobe tuners have become available – though they tend to be more expensive than other tuners.

So, how do they work? Strobe tuners use a strobe light powered by the instrument (via a microphone or TRS input jack) to flash at the same frequency of the note being played. For example, if your 3rd string (G) was in perfect tune, the strobe would flash 196 times per second. This frequency is then compared visually against a reference pattern marked on a spinning disc that is configured to the correct frequency. When the frequency of the note matches the pattern on the spinning disc, the image appears completely still. If not in perfect tune, the image appears to jump around.

Why Strobe Tuners are So Accurate

Strobe tuners are incredibly accurate – up to 1/10000th of a semitone. That’s 1/1000th of a fret on your guitar! To put that into perspective, check out the example of the woman running at the beginning of the video below. It’ll help you understand why strobe tuners are so accurate.

Using a Strobe Tuner

Using a strobe tuner is pretty straightforward. All you need to do is:

  • Plug your guitar into the tuner
  • Play the note you want to tune
  • Observe the strobe light
  • Adjust the tuning until the strobe light is still
  • Repeat for each string

And you’re done! Strobe tuners are a great way to get your guitar in perfect tune – and have a bit of fun while you’re at it.

Understanding Pitch Measurement

What’s a Guitar Tuner?

Guitar tuners are the ultimate accessory for any guitar-strumming rockstar. They may look simple, but they’re actually quite complex. They detect pitch and tell you when a string is sharp or flat. So, how do they work? Let’s take a look at how pitch is measured and a bit about sound production.

Sound Waves and Vibrations

Sound is made up of vibrations that create compression waves, also known as sound waves. These waves travel through the air and create areas of high pressure called compressions and rarefactions. Compressions are when the air particles are compressed, and rarefactions are when the air particles are spread apart.

How We Hear

Sound waves interact with the air molecules around them, causing objects to vibrate. For example, our eardrums vibrate, which causes the tiny hairs in our cochlea (inner ear) to vibrate. This creates an electrical signal that our brains interpret as sound. The volume and pitch of a note depend on the attributes of the sound wave. The height of the sound wave determines the amplitude (volume) and the frequency (number of sound waves per second) determines the pitch. The closer the sound waves are, the higher the pitch. The further apart the sound waves are, the lower the pitch.

Hertz and Concert Pitch

The frequency of a note is measured in Hertz (Hz), which is the number of completed sound waves per second. Middle C on a keyboard has a frequency of 262Hz. When a guitar is tuned to concert pitch, the A above middle C is 440Hz.

Cents and Octaves

To measure smaller increments of pitch, we use Cents. But it’s not as simple as saying there are a certain number of Cents in a Hertz. When we double the frequency of a note, the human ear recognizes it as the same note, just an octave higher. For example, middle C is 262Hz. C in the next highest octave (C5) is 523.25Hz and in the next highest (C6) 1046.50hz. This means the increase in frequency as a note increases in pitch is not linear, but exponential.

Tuners: The Funky Way They Work

Types of Tuners

Tuners come in all shapes and sizes, but the basic concept is the same: they detect a signal, figure out its frequency, and then show you how close you are to the correct pitch. Here are some of the most popular types of tuners:

  • Chromatic Tuners: These bad boys detect the nearest relative note while you’re tuning.
  • Standard Tuners: These show you the notes of the guitar in standard tuning: E, A, D, G, B, and E.
  • Strobe Tuners: These use a spectrum analyzer to extract the fundamental frequency from the overtones.

How They Work

So, how do these funky little machines work? Well, it all starts with a weak signal from the guitar. This signal needs to be amplified, converted to digital, and then output on the display. Here’s a breakdown:

  • Amplification: The signal is increased in voltage and power using a preamp, so the initial weak signal can be processed without increasing the signal-to-noise ratio (SNR).
  • Pitch Detection and Processing: The analog sound waves are recorded at specific intervals and converted to a value by an analog to digital converter (ADC). The waveform is measured against time by the device’s processor to establish the frequency and determine the pitch.
  • Extracting the Fundamental: The tuner has to separate the additional overtones to accurately detect pitch. This is done using a type of filtering based on an algorithm that understands the relationship between the fundamental and the overtones produced.
  • Output: Lastly, the pitch detected is analyzed and converted to a value. This number is then used to display the pitch of the note compared to the pitch of the note if it were in tune, by utilizing a digital display or a physical needle.

Tune Up with Strobe Tuners

What are Strobe Tuners?

Strobe tuners have been around since the 1930s, and they’re pretty darn accurate. They’re not the most portable, but recently some handheld versions have been released. Some guitarists love ’em, some hate ’em – it’s a love-hate thing.

So how do they work? Strobe tuners use a strobe light powered by the instrument (via a microphone or TRS input jack) to flash at the same frequency of the note being played. So if you’re playing a G note on the 3rd string, the strobe would flash 196 times per second. This frequency is then compared visually against a reference pattern marked on a spinning disc that’s been configured to the correct frequency. When the frequency of the note matches the pattern on the spinning disc, the image appears still. If it’s not in perfect tune, the image appears to jump around.

Why are Strobe Tuners So Accurate?

Strobe tuners are incredibly accurate – up to 1/10000th of a semitone. That’s 1/1000th of a fret on your guitar! To put it into perspective, check out the video below. It’ll show you why strobe tuners are so accurate – just like the lady running in the beginning.

The Pros and Cons of Strobe Tuners

Strobe tuners are awesome, but they do come with some drawbacks. Here’s a quick rundown of the pros and cons:

  • Pros:
    • Very accurate
    • Handheld versions available
  • Cons:
    • Expensive
    • Fragile

Tuning Up with Portable Guitar Tuners

Korg WT-10: The OG Tuner

Back in 1975, Korg made history by creating the first portable, battery-powered tuner, the Korg WT-10. This revolutionary device featured a needle meter to display pitch accuracy, as well as a chromatic dial that had to be manually turned to the desired note.

Boss TU-12: The Automatic Chromatic Tuner

Eight years later, Boss released the Boss TU-12, the first automatic chromatic tuner. This bad boy was accurate to within 1/100th of a semitone, which is way better than the human ear can detect.

Chromatic vs. Non-Chromatic Tuners

You may have seen the word ‘chromatic’ on your guitar tuner and wondered what it meant. On most tuners, this is likely to be a setting. Chromatic tuners detect the pitch of the note you’re playing relative to the nearest semitone, which is helpful for those who don’t always play in standard tuning. Non-chromatic tuners, on the other hand, only show the note relative to the nearest note of the 6 available pitches (E, A, D, G, B, E) used in standard concert tuning.

Many tuners offer both chromatic and non-chromatic tuning settings, as well as specific instrument settings that take into account the different overtones produced by different instruments. So, whether you’re a beginner or a pro, you can find the right tuner for you.

Guitar Tuners: From Pitch Pipes to Pedal Tuners

Handheld Tuners

These little guys are the OG of guitar tuners. They’ve been around since 1975 and are still going strong. They’ve got a microphone and/or ¼ instrument input jack, so you can get your guitar sounding just right.

Clip-on Tuners

These lightweight tuners clip onto the headstock of your guitar and detect the frequency of vibrations produced by the guitar. They use Piezo crystals to detect changes in pressure caused by vibrations. They’re great for tuning in noisy environments and don’t use up a lot of battery power.

Soundhole Tuners

These are dedicated acoustic guitar tuners that live inside the soundhole of your guitar. They usually feature a highly visible display and simple controls, so you can quickly get your guitar in tune. Just watch out for ambient noise, as it can throw off the accuracy of the tuner.

Pedal Tuners

These pedal tuners look just like any other pedal, except they’re designed to get your guitar in tune. Just plug your guitar in with a ¼” instrument cable and you’re ready to go. Boss was the first company to introduce pedal tuners to the world, and they’ve been a hit ever since.

Smartphone Apps

Smartphones are great for tuning your guitar. Most phones can detect pitch using either an onboard microphone or by direct line. Plus, you don’t have to worry about batteries or cords. Just download the app and you’re ready to go.

Tuning Up with Polyphonic Tuners

What is Polyphonic Tuning?

Polyphonic tuning is the latest and greatest in guitar tuning technology. It detects the pitch of each string when you strum a chord. So, you can quickly check your tuning without having to tune each string individually.

What’s the Best Polyphonic Tuner?

The TC Electronic PolyTune is the most popular polyphonic tuner out there. It offers chromatic and strobe tuning, so you can get the best of both worlds.

Why Use a Polyphonic Tuner?

Polyphonic tuners are great for quickly checking your tuning. You can strum a chord and get an instant readout of each string’s pitch. Plus, you can always fall back on the chromatic tuning option if you need to. So, it’s fast and reliable.


In conclusion, electronic tuners are a great way to accurately tune musical instruments. Whether you’re a professional musician or just a beginner, having an electronic tuner can make tuning your instrument much easier and more accurate. With a variety of options available, from pocket-sized LCD tuners to 19″ rack-mount units, there is an electronic tuner to fit everyone’s needs. Remember to take into account the type of instrument you’re tuning, as well as the accuracy you need, when choosing an electronic tuner. With the right electronic tuner, you’ll be able to tune your instrument with ease and accuracy.

I'm Joost Nusselder, the founder of Neaera and a content marketer, dad, and love trying out new equipment with guitar at the heart of my passion, and together with my team, I've been creating in-depth blog articles since 2020 to help loyal readers with recording and guitar tips.

Check me out on Youtube where I try out all of this gear:

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