Reviewed: Ernie Ball Expression Tremolo Pedal

CMC Music | | Expect To Pay: $395

Here’s to the unsung hero of the effects world. If distortion is the squawking, loud-mouthed first born and reverb the sullen middle child, then surely the undulating subtlety of tremolo is the oft overlooked youngest who, while not wanting to make too much of a fuss about itself, rounds out the family in a way that would be sorely missed in its absence. When Link Wray let the tubes of his hotter than hell Fender amp shudder on his trailblazing track ‘Rumble’, he allowed it to come into its own as a sought after texture for tone tourists the world over. Since then, tremolo has taken on many shapes and forms and has spawned any number of equally fascinating time-based modulations in its wake. However, the fact remains that no bag of tricks is complete without that glistening, steady warble. Enter the next logical amendment to the gold standard, Ernie Ball’s Expression Tremolo.

Ernie Ball have always positioned themselves as absolute innovators where unsung heroes are concerned. Their strings are the preferred choice for more discerning players and when their volume and expression pedals hit the market a mere forty years ago, they changed the way we express ourselves from the pedalboard up. About a year and a half ago they shimmied further into the effects world with two treadle units each dedicated to a different sonic texture. The Ambient Delay and Overdrive offered real time control over the amount of effect at play without having to lift a finger off the fretboard, and while they may be slowly finding real estate on pedalboards, the third in the family is sure to prove itself indispensable much quicker than its predecessors.


Simply put, the Expression Tremolo gives your feet the job that Link’s hands had to do. Five different waveforms populate the faceplate – sine, square, harmonic, slow rise and slow fall – and the footboard has the ability to ride those in a number of different ways. Push button Depth and Rate knobs allow you to assign either or both to the treadle. If you want to speed up the tremolo waveform over a phrase, light up the rate knob only. At this end of the bargain there is a whole world of bird noises and engine-speeding-up texture that heretofore only DAW-bound automation could conjure. If you want to have the tremolo gradually deepen over a different phrase, the Depth button is your guy.



Using either knob to set the maximum level of either operation and/or a combination of both offers a tonne of versatility. With a classic sounding spring reverb in the chain, this pedal expands the tremolo world with as much cleverness and trickery as other effects without sacrificing the subtlety that makes it irreplaceable in the first place. My favourite field to wander in was the harmonic setting, plunging headlong into the spring reverb at full tilt. It offered a sense of vintage warmth not unlike a tube amp at its hottest: chewy, autumnal, familiar and ripe with newness all at once.


Necessity may be the mother of invention, but without intuition it would be way behind the eight ball most of the time. Ernie Ball are impeccable at answering questions that many players hadn’t yet thought to ask, but having heard the answer, can’t deny the need. The Expression Tremolo is a uniquely clever augmentation to a rich tradition and shines a light down an often neglected, but nonetheless scintillating tonal pathway.

Hits and Misses


Clever functionality

Tasty textural and harmonic capacity

A snappy purple chassis