Premier Guitar features affiliate links to help support our content. We may earn a commission on any affiliated purchases.

Electro-Harmonix Attack Decay Review

A revamped classic filter with modern versatility.



Wide variety of tape-like tonal manipulations and more at your service. Great price!

Mono only. Not intuitive. Expression pedal a must.


Electro-Harmonix Attack Decay


Ease of Use:



In a recent PG interview, Gang of Four’s Andy Gill described Electro-Harmonix’s MicroSynth as “fiddly to use.” Ditto for this sibling, the Attack Decay Tape Reverse Simulator, with its 10 controls, expression pedal capability, effects loop, and onboard fuzz and compression. Spend hours developing some proficiency with the box and the backwards guitars of “Tomorrow Never Knows” or “Are You Experienced,” the airy slide of “Breathe,” and the bleeping, droning textures of Fripp & Eno and Radiohead can be at your toe-tip—thanks in part to how well the Attack Decay plays with reverbs, delays, and other effects via the loop. With exploration, it’s also possible to dial in a clipped decay similar to stringed Japanese and African folk instruments, bowed string tones, synth-like sounds, and plenty of other ear carrots that’ll draw you deep down a rabbit hole.

Fresh Decay
EHX initially made the Attack Decay in 1980 and 1981. Originals are rare and typically cost more than $1,000. This new version of the polyphonic volume envelope filter’s updates include the aforementioned expression pedal input, effects loop, and three easy-to-use memory presets. The new Attack Decay’s blood and guts are inside a sturdy metal 4" x 4.75" shell with switches for bypass and harmonix/preset (the latter for fuzz and presets). Volume, blend, attack, and decay dials are self-explanatory, and so are the small volume, tone, and harmonix (gain) dials that govern the fuzz, which offers 13 dB of gain. At the upper left are three LEDs indicating which preset is activated, plus poly and sensitivity controls. Activating the poly mode gives each note its own envelope—creating super-lush and synth-like colors. The sensitivity knob sets the threshold at which string attack is detected. And in poly mode, the maxed-out sensitivity control will create bubbling note trails. Flipped-out tremolo effects—almost like a sequencer—are also available, in continuous envelope mode. With all that functionality plus 1/4" jacks for input, output, effects send and return, and expression, there’s no room for a battery, so the Attack Decay comes with a 9V/200mA adaptor.

Heel-back yielded luxurious swells and toe-down produced rapid sci-fi tremolo with slapback.

Classic to Drastic
Keeping the manual handy is essential. The footswitches have multiple functions, so getting into the tremolo (continuous envelope) zone, for example, isn’t intuitive. But once there, it was easy to use the decay envelope to create backwards-tape-style sounds and other weirdness. With the poly button on, sensitivity floored, volume at noon, blend all-in, fuzz lightly on, and attack and decay at 9 o’clock, the result was like a cello trailed by the tinkling notes of a warped marimba. You’ll need an expression pedal to get the most out of swells, multi-string bends, and various settings. Using a footswitch-and-button-pushing sequence, the expression can be set to control each of the volume, blend, attack, and decay knobs individually. I enjoyed linking it to the decay function, so heel-back yielded luxurious swells and toe-down produced rapid sci-fi tremolo with slapback, with access to points between. Activating the fuzz circuit with the heel back and the fuzz’s tone all the way up got into Fripp-like sustain.

The Verdict
The Attack Decay is not for the plug-and-play set, but rewards study with a menu of the sweet and the weird. If not for the presets, it might be too “fiddly” for stage. But with a wide palette and a nice price, it merits investigating.

Watch the First Look: