The Ernie Ball Expression Series Tremolo is a tremolo and reverb pedal built into an expression pedal format: a rocker-style treadle you work with your foot, in the manner of a volume or wah pedal. Ernie Ball describes it as two effects in one enclosure, with a built-in reverb alongside the tremolo circuit1. It sits in the tremolo and reverb families, and its closest relatives are the expression pedals it borrows its shape from.
How the treadle works
The rocker pedal is the heart of the design. In the heel down position the effect is bypassed and the pedal passes a buffered unaffected signal; as you press the treadle toward toe down, the effect comes in and rises to the maximum set by the knobs. That gives continuous foot-sweepable control over tremolo speed, depth and/or reverb, depending on which parameters you have assigned to the pedal1.
Controls
| Control | What it does |
|---|---|
| Depth | Intensity of the tremolo; pressing the knob assigns it to the pedal, its LED lights, and its setting becomes the toe down maximum1 |
| Rate | Speed of the tremolo; pressing the knob assigns it to the pedal, its LED lights, and its setting becomes the toe down maximum1 |
| Wave shape | Selects one of five tremolo wave shapes: ramp up, ramp down, sine, square and harmonic1 |
| Reverb | A single control that increases the length as well as the blend from wet to dry; set it to the desired toe down maximum to add reverb to the pedal's control1 |
| Rocker pedal | Continuous foot-sweepable control over tremolo speed, depth and/or reverb; heel down bypasses the effect with a buffered unaffected signal, toe down is the maximum set by the knobs1 |
The LEDs next to the Rate and Depth controls show which tremolo parameters the treadle is controlling. Pressing both knobs assigns rate and depth simultaneously, and if neither is selected the pedal controls both, with toe down behaving as if both knobs were turned all the way up1.
Using it as reverb only
Because the reverb is a separate circuit with its own knob, the pedal can run as a reverb alone. Select the depth and rate controls, set both knobs all the way down to take the tremolo out, then set the reverb where you want it. The treadle then sweeps the reverb by itself1.
What reviewers said
Sweetwater's Don Carr, demonstrating the pedal in a review video, summed it up this way:
"I like that this pedal is versatile Compact and super easy to control"
Videos
Premier Guitar
Premier Guitar
Pete Thorn
Questions
What tremolo wave shapes does the Ernie Ball Expression Tremolo have?
The wave shape knob selects one of five tremolo wave shapes: ramp up, ramp down, sine, square and harmonic. Each shape changes the way the volume modulation rises and falls, so the same rate and depth settings can produce anything from a smooth swell to a harder, more chopping pulse.
Can the Expression Tremolo be used as a reverb only?
Yes. To use only the reverb, select the depth and rate controls and set both knobs all the way down, which takes the tremolo out of the picture, then set the reverb knob where you want it. The treadle then sweeps the reverb on its own.
Is the Ernie Ball Expression Tremolo true bypass?
No. In the heel down position the effect is bypassed and the pedal passes a buffered unaffected signal rather than a true bypass connection. The buffered path is what you hear whenever the treadle is at heel down.
What can the treadle control on the Expression Tremolo?
The rocker pedal gives continuous foot control over tremolo speed, depth and/or reverb, depending on which knobs are assigned to it. Heel down bypasses the effect with a buffered unaffected signal, and toe down reaches the maximum set by the knobs.
How do I assign the Rate or Depth knob to the pedal?
Press the Rate or Depth knob to assign it to the treadle; its LED lights and its current setting becomes the toe-down maximum. LEDs next to the two controls show which tremolo parameters the pedal is controlling. Pressing both assigns rate and depth at the same time, and if neither is selected the pedal controls both, with toe down acting like both knobs turned all the way up.
Sources (1)
- Ernie Ball Expression Series Tremolo Pedal Review, Sweetwater, 2018-05-08