7th April, 2022 - Michael Hahn

Mechanically, an expression pedal is a simple device. In most cases, expression pedals consist of a single passive potentiometer with a TRS output connection. Some designs offer multiple outputs, configurable ranges, and other features, but they all perform the same essential function.

In a typical setup, you connect the pedal's output to an expression control input on your effect. Different pedals offer various configurations for controlling their parameters, but I'll get into that below.

Why use an expression pedal?

Changing effect controls on the fly adds a new dimension to your playing.

After all, sound texture is a vital part of any musical arrangement. Emphasizing a passage with effects is a powerful trick for building intensity and atmosphere.

But controlling specific parameters can take it even further. For example, there are endless ways to create drama with a well-timed adjustment to your sound's timbre.

Not only that, some effects depend on manual control to create their signature sound.

For example, you're probably familiar with the most common expression-controlled pedal—wah. However, the vocal quality of the effect relies on manual sweeps of the filter that match your playing.

If you've ever wished you had a third hand to tweak your pedal settings as you play, expression pedals can give you the flexibility to play your effects like an instrument.

Five creative ways to use your expression pedal

Expression pedals can be set up to control just about any parameter you want. Depending on the capabilities of the pedal you connect them to, you may be able to choose from many different options.

I’ll break down five common ways to use expression pedals and explain the results they produce to give you some ideas to get started.

Wet/dry blend

The blend of wet and dry signal determines the overall strength of ambience effects like delay and reverb.

Varying the wet/dry balance with an expression pedal can create contrast between sections, or provide a textural effect at extreme settings.

Controlling wet/dry mix is as simple as moving the expression pedal to the heel position and setting the mix control fully counterclockwise. Hold the save button to assign the expression value to the heel and repeat the process with the mix control clockwise and the pedal in the toe position.

Now you can gradually fade in washes of ambience that obscure your dry signal completely at the highest setting.

Delay oscillation

Who doesn’t love the classic runaway delay oscillation effect? When it’s a great vintage-style delay, the unique distortion and wailing trails are always fun to play with.

When you adjust the delay time, the oscillation pitch changes as the signal feeds back into itself.

The Echosystem’s tape mode can be configured for expression control of the delay time parameter. With the feedback set high enough you can use the expression pedal to “play” the pitched oscillation of the delay, even as you play new notes into the feedback loop.

It’s a great way to get musical wails and unpredictable pitched feedback as you play.

Modulation speed and depth

Modulation is a broad category of effects pedals.

Despite the different styles, this effect type almost always relies on an LFO to control the speed and depth of its action.

LFO stands for low-frequency oscillator. This waveform is so slow that you don't perceive it as a musical tone. Instead, the LFOs frequency, depth, and waveshape define the character of a modulation effect's sweep.

Changing the rate or depth of the LFO sweep with an expression pedal has unique effects for different modulation types.

For example, setting an expression pedal to control the Empress Tremolo 2's rate lets you ramp up and down from a shaky stuttering effect to a slow pulsing tone.

Johnny Greenwood famously used this technique in the rhythm guitar track on "Bones" from The Bends.

Pitch shift

Another classic rocker-controlled effect is the dive-bomb pitch shift made famous by the Digitech Whammy.

The original pedal comes with a rocker treadle built-in, but it's large, heavy, and requires a high current power supply.

If you don't want to devote all that pedalboard real estate to a full-size whammy pedal, you can accomplish the same effect using an expression pedal and a compact pitch shifter like the EHX Pitch Fork.

Multiple parameters

Several of the best expression pedals feature additional outputs to control two or more parameters at once.

Sweeping the range of multiple controls creates a morphing effect that blurs the parameters together.

Also many digitally controlled pedals allow for control of multiple paramaters at once. The Empress Reverb and Echosystem offer comprehensive parameter control via expression pedal. In fact, you can blend between two positions on every knob as you rock the expression pedal from heel to toe.

The ZOIA is inspired by the flexibility of modular synthesis. It offers expression control of nearly every parameter in any combination and direction!

If you're looking to create evolving textures with hands-on control of a whole chain of processors, there's no better way than with ZOIA.

The control port on the Reverb, Echosystem and ZOIA can be used for

expression pedals, MIDI, an external switch, tap tempo, or CV.

 If you're in the market for an expression pedal, there are plenty of great options to suit any budget.

Here are six top picks to get you started.

Moog EP-3

The Moog EP-3 is a cost-effective and well-built expression pedal. It features a single output and comes with a 6" TRS cable if you don't have one on hand.

The EP-3 is among the most affordable choices on this list, but its construction is mostly plastic. Keep that in mind if you need a more roadworthy option but I've had one for years that has taken a beating and works flawlessly.

Mission Engineering EP-1

Mission Engineering takes expression pedals seriously.

They have a vast line of options that cater to the specific expression needs of popular modern gear.

The standard EP-1 model is a solid all-around choice in a familiar full-size wah style enclosure.

Boss FV-30

Boss's latest take on rocker-style pedals is a robust all-metal design that feels great underfoot without taking up too much space.

It features dual outputs for controlling two effects at once and range controls to set the boundaries of the sweep.

Source Audio SA161

Source Audio's SA161 is another great dual output expression pedal with solid build quality and multiple outputs for controlling two different parameters.

Dunlop DVP3

If you're looking for a pedal to work as a volume pedal and an expression pedal in a compact package, the Dunlop DVP3 is one to consider.

It offers a durable design with adjustable rocker tension for the perfect feel.

Any Volume Pedal

Speaking of double duty, any volume pedal can act as an expression pedal if it’s connected with the right type of cable.

The one you’ll need is a ¼” TRS to dual ¼” TS cable. These are sometimes called insert cables because they’re used to add pro audio gear like compressors to the signal flow of a mixer.

With the tip TS jack plugged into the volume pedal’s input and the ring TS jack in the output, your volume pedal will behave just like a TRS expression pedal.