Complete Guide To Expression & Volume Pedals

Volume Pedal & Expression Pedal Guide

Wondering what the difference between a volume pedal and an expression pedal is? The two pedals may look alike, but that’s where the similarities end!

Both pedals offer the ability to craft and shape your tones using your feet to control different variables, but the ways in which they operate are fundamentally different.

In this guide we’ll compare volume pedal vs expression pedal, looking at what they both are, how they both function, and the differences between the two. We’ll also look at a few popular examples of each for those looking to buy.

If you stick around to the very end, I’ll even show you a simple way to hack your volume pedal so that it can be used as an expression pedal!

Table of Contents

What Is The Difference Between A Volume Pedal And An Expression Pedal?

Volume Pedal vs Expression Pedal Differences

In a nutshell, a volume pedal acts as a master volume control, only affecting the overall volume of your guitar signal. An expression pedal can control various different effects parameters depending on what device they are hooked up to. For example, they can alter the length of a delay, or add and remove gain.

It should be noted that an expression pedal can also control volume, but only if the device it is connected to has an expression-ready volume parameter.

A volume pedal also connects in-line to your signal chain, thereby directly affecting the audio signal. Whereas an expression pedal does not, and instead connects directly to the expression pedal input on the device it is controlling.

What Is An Expression Pedal?

An expression pedal is a type of foot pedal that allows a player to control a number of different parameters dynamically and in real-time, such as modulation, volume, delay level, and reverb amount, amongst many others. The parameters it controls will vary depending on what pedal or unit the device is plugged into.

What is an Expression Pedal

In general, they are mostly used to control variables on stompboxes, multi-fx units, keyboards, and MIDI controllers.

They look similar to a wah or volume pedal and are rocked back and forth with the foot in order to control the device they are connected to.

Unlike most regular pedals, an expression pedal does not have an input, as it does not connect to your signal chain. Therefore, it is important to understand that an expression pedal only controls the functions of the device it is hooked up to and does not add to your guitar’s sound by itself.

What Does An Expression Pedal Do?

As we’ve already mentioned, an expression pedal can control a myriad of different parameters – often many at the same time! Let’s take a look at some examples of what they can control when hooked up to different pedals…

Modulation Pedals. Connecting your expression pedal to a modulation pedal such as a Walrus Audio Julianna chorus will allow for control of depth or rate, or even both at the same time! Other best-selling modulation pedals which feature expression pedal support include the Boss MD-500, JHS Unicorn, EHX Stereo Polyphase, and Chase Bliss Wombtone amongst others.

Delay Pedals. Plug into a delay such as a Boss DD-8 and you can control parameters such as level, feedback, or delay time – or all of them at once! Other popular delay pedals that have expression inputs include the EHX Canyon, Strymon El Capistan, TC Electronic Flashback, and the Way Huge Supa-Puss to name but a few.

Overdrive and Distortion Pedals. Hook up to something like an EHX Big Muff Deluxe and you will be able to sweep the mids in real-time using your expression pedal! It is rarer to find expression-ready overdrive and distortion pedals.

Multi-FX Units. If your multi-effects unit does not already have one, many will have support for an external expression pedal, which will open up a ton of different options for you. Other models which already have a pedal, such as the Line 6 Helix Floor, have support for up to 3 additional expression pedals for endless possibilities!

When connecting an expression pedal to a multi-fx unit for the first time you may need to calibrate it. This generally involves simply letting the unit know where both the heel-down and toe-down positions are.

How Does An Expression Pedal Work?

An expression pedal works by varying a control voltage sent to equipment such as a guitar pedal or a synth. By altering this voltage we can change various parameters on the device the expression pedal is connected to. This could include chorus depth, volume, delay level, and reverb amount, amongst many others.

Let’s look at this in a bit more detail, for those of you who really want to nerd out!

Inside the pedal, you’ll find a passive potentiometer, much like those found in the volume and tone knobs on your guitar. As the pedal is rocked back and forth, this potentiometer rotates along with it, thereby varying the electrical resistance inside.

This potentiometer is then attached to an output jack which you can use to connect the expression pedal to the device you want to control.

The pedal works by manipulating the voltage being sent to the device. This voltage is continually read by the connected pedal or device, allowing it to work out the position of the expression pedal and thereby alter the parameter being controlled.

In almost all cases, expression pedals do not require a power source, as the control voltage will be created by the device they are hooked up to. The control voltage will usually alternate between 0 and 5 volts DC, but this will obviously vary depending on the equipment you are connected to.

Where Does An Expression Pedal Plug Into?

As an expression pedal does not connect in-line to your signal chain, you can only use it with a device that has a dedicated expression pedal input. This equipment is often referred to as being ‘expression ready‘.

This means that you can place the pedal wherever you like on your pedalboard, as long as it is hooked up to the device you need to control. This is great as these pedals are generally fairly large and could be awkward to find space for otherwise.

The expression pedal input will most commonly require a special cable with a 1/4″ TRS stereo plug, not a standard guitar (TS) cable. TRS stands for tip, ring, sleeve, and refers to the parts of the jack that the various conductors are wired up to. Although TRS is the most common, some pedals do use TS, so make sure to consult the product webpage or manual.

Expression Pedal Cable TRS Connection Diagram

The main difference between a guitar cable (TS) and a TRS cable is the number of conductors – 2 on a guitar cable, and 3 on a TRS cable. You can easily spot the difference by looking at the black rings on the jack – a TRS cable has two (see diagram above), whereas a regular guitar cable (TS) has just one.

Another consideration is that some pedals are designed specifically to be used with certain devices, which means that you need to check their polarity for compatibility. The pedal I have recommended below has a handy polarity switch to ensure that it can be used with as wide a range of devices as possible.

What To Look For In An Expression Pedal?

Expression pedals are all very similar in terms of how they function, which means that the difference between a cheaper pedal and a more premium one is often just the build quality.

This is great news as it means you don’t necessarily have to spend an arm and a leg to get a perfectly usable pedal. Here are a few key things you might like to consider when shopping around.

Metal vs Plastic Casings. Metal designs are more expensive but offer more durability. Plastic is cheaper but less rugged.

Size. Do you need it to fit into a small space on your pedalboard or gigbag, or is space not at a premium?

Long vs Short Throw. This depends on how quickly you would like to be able to change parameters.

Return Spring. This is great if you want the pedal to automatically return to the heel position. Not so great if you’d like to leave the pedal at a specific position in its range.

Tension Adjustment. Would you like to dial in the resistance of the pedal to your exact liking?

Toe Switch. A toe switch will allow you to switch the pedal off when not in use.

What Is The Best Expression Pedal?

For the last couple of years, I have personally been using a Moog EP-3 pedal, which I have no real complaints about. Price-wise, it sits around the middle of the pack at around $50 at the time of writing. For the money, I think it’s tough to beat.

It’s very solidly built (albeit of plastic!), has a nice long and smooth sweep, and is compatible with a huge variety of different devices thanks to its handy polarity switch. I tend to look after my gear, so this unit has been an excellent affordable choice for me.

You can check it out here if interested.

If you are after something a little more rugged and with additional features, then I would definitely suggest taking a look at Mission Engineering’s range for more premium choices.

What Is A Volume Pedal?

A volume pedal is similar in appearance to a wah pedal and is used to control the master volume of your setup. Depending on where you place the pedal within your signal chain you are able to add some incredibly unique and dynamic nuances to your sound. It can also be used to quickly mute your signal.

What is a Volume Pedal

Volume Pedal vs Volume Knob

You may be wondering ‘why do I even NEED a volume pedal? I already have a volume knob on my guitar!‘.

Firstly, a volume pedal is generally easier to use while playing, especially if you have a guitar with awkwardly positioned pots! In addition, you also have more precision and speed when using a pedal, as you are able to cover a wider range of movement faster.

The second reason to use a volume pedal is that you can create different effects depending on where you place it within your signal chain. You can then combine pedal and guitar volume pots to create a ton of different sonic options.

Find out more about how placement affects the effect of a volume pedal further down the page.

How To Use A Volume Pedal

There are no concrete rules on how to use a volume pedal, but here are a few common ways that they might be utilized for creative effect.

Volume Swells. Use your pedal to create orchestral, violin-style sounds! With the volume completely off, play a note or chord and then bring the volume in before fading the sound out again. This is an effect you can also achieve using your guitar’s volume knob, but it is easier to pull off using a pedal. Add reverb for an awesome atmospheric effect!

A Boost. While a boost pedal will give your signal an immediate boost, using a volume pedal instead gives you the option of a more gradual and dynamic effect.

Signal Mute. Use the pedal to immediately mute your sound – perfect for guitar changes at gigs or for breaks. You can also use it to gradually fade your guitar out at the end of songs.

Controlling Volume In A Specific Way. As I’ve already mentioned above, the placement of your pedal greatly affects how your signal reacts. For example, place it in your effects loop to maintain the same level of gain no matter what level the pedal is at. Learn more about placement in the next section!

But wait, there’s more! Check out the excellent video below to hear some of the more exotic sounds that you might not be aware you can achieve with a volume pedal!

Where To Put A Volume Pedal In The Signal Chain

You can place a volume pedal pretty much anywhere in your signal chain depending on how you would like to use it.

Placing it at the end of your chain will allow it to act as an overall master volume for your entire signal. You will be able to lower the volume without losing any of the overdrive or gain from your pedals. This is also the best position if you would like to immediately end a song without any reverb or delay trails carrying on.

Alternatively, you can also place it at the start of your signal chain to control only the volume of your guitar. This will be similar to controlling the volume pot on your guitar, albeit with more control and sensitivity. It will allow you to clean up your sound by removing gain.

The most common position to place a volume pedal, however, is somewhere in the middle of your chain. I.e. after your gain section, but before your modulation pedals. In this position, you are able to lower volume without losing any gain while still retaining delay and reverb effects.

Essential viewing! The following video shows in a really concise manner how moving the volume pedal around in your signal chain will affect the sound.

Active vs Passive Volume Pedal Differences

What is the difference between active and passive volume pedals? These are the two main types of volume pedals, but which to choose!?

A passive volume pedal is a simple unit that essentially performs the same task as the volume pot on your guitar. They are the cheaper of the two pedal styles as they are essentially just a box containing a potentiometer.

You won’t be surprised to hear that they do not require a power source, making them very convenient to use.

The main downside to passive volume pedals is that they can be sensitive to where they are placed in the signal chain, as well as the type of instrument that they are connected to.

In the worst-case scenario, they can result in ‘tone suck’, which is usually a signal loss in the higher frequency range.

To try and avoid this you should choose a passive pedal that has an impedance level close to what your pickups will expect:

  • A pedal with a potentiometer in the range of 250-500K is best suited to a guitar with passive pickups.
  • A pedal in the range of 25-50K is better suited for guitars with active pickups.

An active volume pedal is the more expensive choice of the two (roughly twice as pricey on average) as it contains additional features such as a buffer circuit, and sometimes extras such as boost and tuner isolation.

In addition, an active volume pedal requires a power supply from a battery or external PSU.

Crucially, an active pedal solves the ‘tone suck‘ issue found in passive volume pedals thanks to the buffer circuit they employ. The buffer makes sure that any effects and cables after the volume pedal do not degrade your signal.

It also does not matter if your guitar has active or passive pickups, as any active volume pedal should play nicely with either.

You can hear the difference between the two (including tone suck) in the helpful video below.

What Is The Best Volume Pedal?

There is no ‘best‘ volume pedal as everyone’s needs will be different, but here are a couple of industry standards depending on whether you want a passive or active choice.

Passive Volume Pedal Suggestion. If you’re after a more affordable passive choice then the most popular option is almost certainly the Ernie Ball VP Jr. This well-made pedal is available with a 250k potentiometer for passive electronics, and a 25k pot for active pickups.

Click Here To Check Out The Ernie Ball VP Jr

Active Volume Pedal Suggestion. Spending a little more money will get you the Mission Engineering VM-Pro with buffer. The pedal has a ton of handy features, such as adjustments for passive and active pickups, output impedance, and even a switch to restore high-end sounds on rigs with very long cable runs! And of course, you have that buffer to prevent the dreaded tone-suck.

Click Here To Check Out The Mission Engineering VM-Pro

How To Use A Volume Pedal As An Expression Pedal

Here’s a clever hack if you already own a volume pedal and would like to try using it as an expression pedal instead. This won’t work with 100% of volume pedals, but as long as yours is low impedance, you should be good to go.

This trick will only work using a Y-cable with a TRS plug on one end and two mono 1/4″ plugs on the other.

Simply connect the Y-cable to the input and output jacks of your volume pedal, and then connect the other end to the expression input on the device you need to control. Pretty easy, right?

Make sure to connect the ‘ring‘ plug into the input, and the ‘tip‘ plug into the output of the volume pedal (as shown in the diagram below!).

How To Convert a Volume Pedal To An Expression Pedal

The only downside is that for the first half of the pedal movement there will not be much of an effect.

Although a similar hack can be used with TS expression pedals, it is not likely to be compatible with very many devices.

Frequently Asked Questions

What Is The Difference Between a CV and Expression Pedal?

An expression pedal is not the same as a CV pedal. Although both pedals are very similar, the main difference is that an expression pedal does not generate the control voltage itself, while a CV (control voltage) pedal does.

This means that a CV pedal requires a battery or its own power supply to function. It is important to check whether or not your device can be used with a Control Voltage pedal, as it could cause damage if not compatible.

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Neal Author Bio
Neal has been playing guitar (left-handed!) for over 20 years, and has also worked in various roles within the guitar retail industry since 2012. He started LeftyFretz in 2010. More Info