ROCKTRON Heart Attack Dynamic Filter / Envelope Filter Q-Tron Type / Stompbox Series

ROCKTRON Heart Attack Dynamic Filter

100% New.
Complete with original box.

Type: Auto-Wah / Envelope Filter Pedal for Guitar (EHX Q-Tron style)

Main Effect: Dynamic harmonic sweep triggered by pick attack

Operation: The harder the attack, the more pronounced the effect

Controls: Sensitivity, Distortion On/Off

Chassis: Rocktron heavy-duty metal

LED: Status indicator

Power Supply: 9V battery or 9V DC Standard (not included)

The Rocktron brand has always held a somewhat unique place in the world of guitar effects. Less marketing-oriented than some major brands, it built a solid reputation among touring musicians thanks to a highly pragmatic approach: robust, easy-to-use tools designed first and foremost to handle the realities of live performance. In the '90s and 2000s, Rocktron perfectly embodied this "plug-and-play" philosophy: reliable, efficient gear designed as a true workhorse. The Heart Attack Dynamic Filter is a direct descendant of that mindset, featuring a personality far more unconventional than the standards of the genre.

At a time when compact pedals are increasingly miniaturized—often cheaply produced and treated as easily replaceable items—the Heart Attack recalls a different vision of gear. A vision from a generation of pedals built to last, featuring massive metal enclosures, solid engineering, and a genuine commitment to longevity. Where many modern clones focus on compactness and low cost, Rocktron offered a true stage-ready tool capable of weathering the years without faltering.

The Rocktron Heart Attack Dynamic Filter occupies a very specific niche in the effects spectrum, sitting at the crossroads of several well-known references. It can be described as halfway between a classic auto-wah like a Cry Baby Auto/Envelope Filter, a more refined and musical approach reminiscent of the Electro-Harmonix Q-Tron, and a signature Rocktron touch that is more "phasey," gritty, and modulated. This blend gives it a unique identity that is difficult to compare directly to any single existing pedal.

From the very first notes, it is clear that this is not just a standard filter: here, everything relies on playing dynamics and pick attack. The harder you play, the more the filter opens up and becomes expressive, delivering an almost living response. The behavior is both responsive and unpredictable, which adds immensely to its character.

What immediately captivates is precisely this organic quality. The Heart Attack responds with extreme sensitivity to your touch, acting like an instrument in its own right integrated into your signal path. At lower sensitivity settings, it delivers round, funky textures that are ideal for subtle grooves and tight rhythm lines. Dialing up the sensitivity pushes the pedal into much more extreme territory: the frequency sweeps widen significantly and take on an almost vocal quality, yielding an expressive, sometimes unstable, but always musical result.

The circuit is further enhanced by a built-in distortion feature. This is not a modern or ultra-precise saturation, but rather an added grain that accentuates the filter's bite and jagged edges. This reinforces the impression of a living effect—one that feels almost uncontrollable at times, but remains incredibly inspiring to play.

As is typical with the Stompbox series, the build quality inspires immediate confidence. A massive metal chassis, a stage-centric design, and simple, efficient ergonomics all point to a pedal engineered for heavy, long-term use. It stands far apart from today's miniaturization standards, where lightweight construction and cost-cutting have often taken precedence over durability.

Ultimately, the Heart Attack Dynamic Filter refuses to be boxed into a single category. It is neither a standard wah nor a simple envelope filter, but rather a hybrid dynamic auto-filter, typical of Rocktron’s experimentation in the 2000s. It is not an exact copy of a specific famous pedal, but rather a cross between a funk auto-wah and an experimental filter, boasting a much quirkier, more expressive, and unpredictable personality than the standard options out there.

In short, it is a pedal that bridges multiple worlds with a distinct identity:

Not a standard wah

Not a simple envelope filter

But a hybrid dynamic auto-filter, typical of Rocktron’s 2000s experimentation

A pedal with real character—sometimes disconcerting, but deeply alive and inspiring for anyone willing to step off the beaten path.