Blackbox Effects Inferno, X-Ray, Cobalt, Ultraviolet 2, Oxygen

Stimulating sounds
Stimulating sounds

During a recent chat with our friends at Willie’s Gui-tars, Minneapolis, we were turned on to an interesting new line of boutique stompboxes made by Blackbox Music Electronics – a small company based in their hometown. Each pedal is handmade, handwired, and handpainted.

We received a selection of five alluring pedals: the Inferno, X-Ray, Cobalt, Ultraviolet 2, and Oxygen. We tested all of them using a late-’70s Les Paul Custom with Duncan pickups and a modded 100-watt Marshall plexi stack. Let’s see how they sound!

First we plugged in the appropriately-named Inferno, which is a red-hot fuzz box about the size of the MXR Distortion+ pedal. The Inferno relies on a hybrid germanium/silicon circuit to shape its tone. The idea behind this circuitry is to combine the classic warmth and vintage fuzz tone of a germanium transistor with the high-gain overdrive tone and response of a silicon transistor. The result is a pedal that produces a combination of fuzz and overdrive effects with excellent tonal definition.

The Inferno has three easy-to-manage controls for Smoke (amount of dirt and input gain), Fire (output volume), and Heat (boost, gain, and compression). It works well for playing music with classic fuzz sounds reminiscent of groups like Bad Company, Led Zeppelin, Yardbirds, Cream, or any style with similar fuzz or overdrive tones.

Type Of Effect: Hybrid germanium/silicon circuit fuzz
Features: Controls for Smoke, Fire, Heat; true bypass on/off stomp switch; operates on 9-volt battery
Price: $260

The X-Ray is a versatile pedal that can provide a smooth, clean signal boost, or add overdrive, depending on how the controls are set. Those controls are More (distortion and clean boost gain), Louder (output volume), and Shape (shape of the distorted waveform and tone of the distortion). Although they are simple to operate, a trip through the manual with this one is important in understanding how the controls work and interact.


Well, most players are accustomed to increasing levels by turning knobs clockwise. However, on this box, you get the most dirt by turning the More and Shape knobs counterclockwise, all the way. You’ll get the most clean boost by turning More clockwise, all the way up. But when the More control is set all the way up, the Shape knob has very little effect on the tone. A bit of experimentation is required to get a full understanding of the features and benefits of this pedal.

The X-Ray also works very well in conjunction with other pedals. For instance, if you use another box for overdrive on rhythm parts, you can use the X-Ray to get the needed volume boost for a solo or lead passage. Additionally, it can be set to maintain the same tone and just add more volume or to add a bit more drive, too. An X-Ray Bass pedal is also available.

Type Of Effect: Overdrive
Features: Controls for More, Louder, Shape; true bypass on/off stomp switch; operates on 9-volt battery
Price: $200

The Cobalt delivers a warm, tube-like tone with clean boost or overdrive, depending on settings. Controls include Gain (input gain), Drive (secondary boost gain and amount of overdrive), Bias (controls headroom, compression, waveform symmetry and crunch) and Volume (output volume and gain). With the variety of controls, the Cobalt can be set for a range of tones from a very clean, transparent boost in volume to a super crunch tone.

Separate Gain, Drive, and Bias knobs allow the user to fully regulate the effect and tailor it for optimum performance with the guitar and amp, as well as to balance it to best suit the player’s attack. Players familiar with the standard array of overdrive and distortion stompboxes (Tube Screamer, Boss Overdrive, Super Overdrive) but find them a bit limiting will likely enjoy the Cobalt.

Type Of Effect: Clean boost/overdrive
Features: Controls for Gain, Drive, Volume, Bias; true bypass on/off stomp switch; operates on 9-volt battery
Price: $280

The Ultraviolet 2 is a quad-channel fuzz with three active filter sections that create a multi-layered distortion effect. The circuit is designed with four parallel fuzz channels; three channels are running through different filters that each affect a different frequency spectrum, while a fourth channel is left unfiltered. Together, the four create a multitextured tone.

There are six control knobs – Fuzz (amount of fuzz and gain), Low Freq (center frequency of the low frequency filter section), Mid Freq (center frequency of the middle frequency filter section), Hi Freq (center frequency of the high frequency filter section), Mix (level of signal from unfiltered fuzz channel which is mixed with the other three filtered channels) and Volume (effect output level). By tweaking the controls, you can adjust the settings for a wide assortment of sounds with varying levels of dirt and sizzle. The Mix control helps keep the effect from getting too dirty or muddy, depending on the sound you’re looking for and the gear you’re using. Effects range from the basic overdrive and fuzz to full-on maximum dirt and heavy fuzz. The three tone knobs provide useful control over the EQ to fine tune the tone. It’s great for getting low-tech sounds, like that broken-speaker or transistor radio effect. Or, set it for a massive wall of fiery fuzz. If you’re in need of a flexible fuzz box that allows full control of the EQ and effect level, the Ultraviolet 2 may be ideal.

Ultraviolet 2
Type Of Effect: Quad Channel Fuzz
Features: Controls for Fuzz, Low Freq, Mid Freq, Hi Freq, Mix, Volume; true bypass on/off stomp switch; operates on 9-volt battery
Price: $330

The Oxygen is a compressor/limiter/noise gate that can also deliver high-gain overdrive and distortion. Controls include Comp (compression), Limit (limiting threshold), Gate (gate threshold), Release (release time for compression and limiting, and sets noise gate attack time – includes five presets), Gain (amount of post compression gain or signal padding) and Dirt (amount of saturation and signal distortion).

The pedal includes an LED indicator and can be used with an optional 9-volt DC power supply. Unlike many typical stompbox compressors, the Oxygen pedal offers many more features that are usually only available on high-tech studio gear. It’s perfect for recording, when you may want a compressor to help stabilize the volume of each note. In live situations, it can be useful for a guitarist playing cleaner passages on electric or acoustic. You can also set the controls to achieve a bit of added dirt for texture. Compressors are frequently used by bass players, and the added overdrive capabilities gives this one an added bonus. Settings will vary based on the instrument and the player’s attack, as well as the desired effect.

Type Of Effect: Compressor/limiter/noise gate
Features: Controls for Comp, Limit, Gate, Release, Gain, Dirt; true bypass on/off stomp switch; LED indicator; operates on 9-volt battery or optional DC power supply
Price: $340

All Blackbox pedals are very responsive to playing dynamics and demonstrated quiet performance – there was no extraneous noise in the signal chain when we used them alone or with other pedals. They operate on 9-volt batteries and include true bypass on/off stomp switches. And each carries a non-transferable lifetime warranty.

Blackbox Music Electronics, 1113 3rd Street NE, Minneapolis, MN 55413, (612) 623-7957, email:, website:

This article originally appeared in VG‘s April ’02 issue. All copyrights are by the author and Vintage Guitar magazine. Unauthorized replication or use is strictly prohibited.

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