Hailed by its creators as the greaest product introduced by Electro-Harmonix in over 20 years, the new Tube Zipper was developed jointly by E-H’s legendary stompbox guru, Mike Matthews, and the mad scientists at E-H, in collaboration with Dutch engineer Tom Barmentloo.

Some players will remember the original E-H Zipper – an envelope filter that’s now a hard-to-find collectible that commands big bucks when found in good working condition. The new Tube Zipper is a far superior creation that not only functions much better and more reliably than the original, but offers a greater selection of tones and enhanced effects.

The Tube Zipper is actually two effects; an envelope filter, and a distortion unit driven by a pair of 12AX7 tubes that plug into the top of the box. The unit is powered by an AC adapter, and it does not run on batteries.

It also features an assortment of onboard controls, including two selector switches, 1/4″ input and output jacks, a standard on/off stomp switch, and six control knobs: Envelope (labeled “ENV”) selects the direction of the filter sweep, Mode selects “Tron” and “Trill” (Tron sweeps smoothly, Trill adds a funky modulation), Resonance sets the center point of the sweep, Frequency sets the filter’s peak frequency when the envelope is not active, and sets the start and stop frequency range, Sensitivity adjusts filter sweep range, Input Gain adjusts the level of the input signal before the filter, Drive adjusts the amount of distortion after the filter, and Master Volume sets the overall output.

Three LEDs indicate power, status, and frequency (which gets brighter as the filter’s peak frequency rises).

It may all sound complicated, but once you read the manual and start fidgeting with controls, it makes sense. Unlike many stompboxes, this isn’t a typical “plug-in-and-go” box; patience and time are definitely required to obtain a understanding of how things work. The manual includes tips on operation and sample settings that will help users become familiar with the controls and sounds that can be created.

We tested the Tube Zipper using a Les Paul Custom fitted with Seymour Duncan JB and ’59 humbuckers plugged straight into our beloved hot-rodded 100-watt Marshall plexi stack and commenced our explorations by going through the manual’s sample settings – and doing much knob-twisting. While each control and switch serves a different purpose, they are interactive and greatly affect each other, so the resulting tones are significantly different with every slight manipulation. It was very easy to dial up unique, inspiring effects, even if it’s a bit of a challenge to remember how you arrived at a particular sound. Even after our tests, we felt there was much we hadn’t discovered.

And those sounds can be a bit difficult to describe… Basically, the Tube Zipper is one of those pieces of gear you’ve got to try for yourself – and it isn’t for everyone. And if you’ve never toyed with an envelope filter, well… let’s just say it controls the “shape” of sounds coming from your instrument. And the effects offered by the Tube Zipper are great because you can tweak every possible parameter to get higher or lower frequencies that will follow your picking attack, and you can adjust the direction and range of the filter sweep.

Just twist the knobs and you’ll discover many surprises, like auto wah, sounds that are a cross between wah and talkbox, basic sweeping effects, and even sounds like a DJ scratching on a record! There’s also the added warmth of tube-driven gain to enhance the tones.

Easier to understand, perhaps, are the distortion effects, which are delivered with the warmth of real tube tone and controlled by adjusting the Input Gain, Drive, and Master Volume. Most players are familiar with these controls.

We’d also recommend the Tube Zipper for bass players, and really, anyone who plays an amplified instrument could find some wild effects and interesting tones.

With the Tube Zipper, E-H proves it’s still creating intriguing tone processors. For stompbox fanatics and those in search of more obscure and exotic tones, the Tube Zipper is likely to be the next “must-have” effect that players will want to add to their collection. It’s sure to provide hours of entertainment and a plethora of cool sounds. The Tube Zipper should be available from most dealers who sell E-H and New Sensor products.

Electro-Harmonix Tube Zipper
Type Of Effect: Tube-driven envelope filter and distortion unit.
Features: Selector switches for Envelope (up/down), Mode (Tron/Trill), Control knobs for Input Gain, Drive, Master Volume, Sensitivity, Frequency and Resonance; true bypass on/off stomp switch, LED indicators for Power, Status (effect on/off) and Frequency, AC power adapter; one year warranty.
Price: $378.
Contact: New Sensor Corporation, 32-33 47th Avenue, Long Island City, NY 11101, (718) 633-5477, fax (718) 937-9111, ehx.com.