Review: T-Rex Shafter Wah and Quint Machine

Founded by guitarists and engineers Lars Dahl and Sebastian Jensen, T-Rex Engineering has been making guitar and bass effects since 1996.
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Founded by guitarists and engineers Lars Dahl and Sebastian Jensen, T-Rex Engineering has been making guitar and bass effects since 1996. The Danish company now has a broad product line that also includes power supplies, cables, and pedalboards. Recent introductions include the two pedals on review here, which showcase T-Rex’s dedication to improving the performance of classic effects.


This versatile pedal features a sturdy metal enclosure and does not use a potentiometer in the rocker—a factor that takes a wear-prone part out of the system, as well as the scratchy noises that pots often create. A 3-way switch on the top panel selects Wah 1, Wah 2, and Yoy Yoy—the latter being a reference to the vintage Schaller Bow-Wow Yoy-Yoy pedal that produced the kind of vocalized “wah” sounds that the name implies (say it to yourself a few times and you’ll get the idea). The Shafter ($199 street) does a good replication, and the Slope control lets you play with the voicing to get just the right response needed for rhythm or lead playing. Basically, the more the Slope knob is turned up, the more dramatic the effect. Slope provides great control over the other two settings as well, with Wah 1 sounding a little sharper and Wah 2 being more full-range and closer in timbre to Skip Pitts’ wah tone on “Shaft.” Lastly there’s a Hotspot button hiding next to the output jack that gives the standard pedal response when pushed in and a more subtle response in the “out” position—the latter being useful when you want to be able to use the full throw of the rocker but with less overall wah effect. Finally, a Boost control adds a lot of gain when turned up and is handy for making the wah stand out a little better, or to actually overdrive an amp or other pedal.

Kudos A flexible wah with a wide range of sounds.
Concerns Not true bypass.


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Offering a lot of sonic thrills for the money, the Quint Machine ($229 street) features +1 Octave (up), -1 Octave (down), and +1 Fifth controls that can de independently adjusted to create everything from classic octave-divider and faux-bass sounds to much more effected tones as you blend different ratios of the controls. The sparkling harmonics created by the +1 Fifth (which adds a note that’s a fifth above whatever you’re playing) are the pièce de résistance here for creating expansive textures that can turn a single note into a shimmering chord, and with the Mix control set to where you’re not hearing any dry signal, the Quint Machine essentially becomes a pocket-sized synthesizer with superb tracking—polyphonically even—at any picking speed. Whether you want to be able to fake 12-string parts on the fly, add subtle dimension to picked-harmonic lines, or nail the lead tone on “Owner of a Lonely Heart,” the Quint Machine does it all, and without sucking volume either. The only thing on my wish list would be an expression pedal input, but otherwise the Quint Machine is pure fun.

Kudos Tons of sounds from a very simple set of controls.
Concerns Not true bypass.