Review: Ernie Ball Expression Tremolo Pedal

(Image credit: Ernie Ball)

Ernie ball makes the best volume and expression pedals in the industry, so it made perfect sense for the company to use their ultra-reliable, pro-quality foot treadle design as the platform for a new series of effect pedals they introduced last year, starting with the Expression Overdrive and Ambient Delay pedals.

The brand-new Expression Tremolo expands Ernie Ball’s pedal effect line by providing the same instant foot-controlled expressive capabilities that make standard stomp boxes with their on/off switches seem plain and limited in comparison. Even without its foot-sweepable tremolo control capabilities, the Ernie Ball Expression Tremolo is an impressive tremolo pedal with a versatile set of controls, but it also includes a cool spring reverb effect that, along with the foot-control feature, makes the Expression Tremolo a must-have for tremolo aficionados.

FEATURES With its compact, pedal board-friendly dimensions, ultra-sturdy aircraft aluminum chassis and incredibly cool (and regal) purple finish with gold logo, the Ernie Ball Expression Tremolo impresses before you even plug it in. Controls are mounted on the front-facing vertical surface and consist of tremolo Depth and Rate knobs and a five-position waveform switch that provides slow rise, slow fall, sine, square and harmonic waveform settings.

There’s also a knob for dialing in the desired amount of Reverb depth. Mono ¼-inch input and output jacks are also mounted on the front, along with a jack for the required 9VDC 100mA power adapter (not included)—the pedal does not operate with batteries. The treadle has a textured non-slip surface, and a PVC-coated braided Kevlar cord delivers consistent control tension and reliable resistance to wear and tear.

PERFORMANCE Every desirable tremolo effect—from smooth sine waves with subtle on/off transitions to the heavy helicopter-like chop of square wave tremolo—is here and can be changed instantly in between (or even during) songs with a flick of the selector switch. The pedal’s Depth and Rate knobs set the maximum volume variation and speed of the tremolo effect. Pressing the momentary switch on either knob will illuminate the corresponding LED, which applies treadle control to that feature.

If only one LED is not illuminated, then that control remains constant as the treadle is moved. On the other hand, when both LEDs are not illuminated, both controls are dynamically controlled by the treadle and are maximized to 100 percent when in the toe-down position, regardless of knob position. The treadle also simultaneously fades in the depth of the reverb effect, with the reverb becoming deeper at the toe-down position, creating wonderfully moody, hypnotic tremolo/reverb textures.

The sound quality of both effects is stellar, and the action of the treadle pedal is smooth as butter. Being able to manually adjust and alter speed settings can lead to some very trippy effects that are worth the price of admission alone.


● The treadle pedal allows users to manually control tremolo-rate and reverb-depth settings simultaneously for gorgeous, moody effects and sonic textures.

● A five-position waveform switch provides settings for slow rise, slow fall, sine, square and harmonic waveforms, providing a full assortment of tremolo effects.

THE BOTTOM LINE Even without the foot-control feature, the Ernie Ball Expression Tremolo would be highly recommended, but with the addition of spring reverb effects and the ability to manually adjust tremolo-rate settings hands free, it’s essential for tremolo fanatics.

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Chris Gill

Chris is the co-author of Eruption - Conversations with Eddie Van Halen. He is a 40-year music industry veteran who started at Boardwalk Entertainment (Joan Jett, Night Ranger) and Roland US before becoming a guitar journalist in 1991. He has interviewed more than 600 artists, written more than 1,400 product reviews and contributed to Jeff Beck’s Beck 01: Hot Rods and Rock & Roll and Eric Clapton’s Six String Stories.