Seymour Duncan SFX-07 Shape Shifter

WHETHER YOU WANT smooth vintage amp-style tremolo (sine wave) or more modern, choppy helicopter effects (square wave), the Shape Shifter does it all. The rate ranges from 1 to 20 cycles per second, which maxes out in a stuttering warble that’s about as fast as the human ear can perceive. The effect produces warm, noise-free tones that preserve the fullness of your guitar’s original signal. The SFX-07’s unique effects lurk within its shape control settings. At the center 12 o’clock setting, the SFX-07 operates like all those other tremolo effects you know and love, but when you dial the shape control to the left, the effect rises in volume more quickly and fades more slowly. When you dial the control to the right, the opposite happens—the effect rises in volume more slowly and fades quickly. Turn the control all the way to the left and the guitar’s attack becomes very percussive and aggressive, while at the rightmost setting the effect sounds similar to a backward recording. The tap tempo function works very well once you’ve gotten used to the “action” of how the footswitch clicks, and it’s easy to nail the perfect tempo every time. The ability to switch ratios from quarter notes to eighths, 16ths or triplets without missing a beat provides numerous creative options to explore, especially if use the Shape Shifter with a device like the T.I.P. Third Hand, which will let you adjust the ratio control with your foot.

THE BOTTOM LINE WITHOUT A DOUBT, the SFX-07 is the most versatile tremolo pedal in its price range available today. If you want to emulate the classic tremolo effects of vintage amps that are priced well beyond your budget, explore modern textures and new effects or all of the above, the Shape Shifter is a great choice whether you’re looking for your first tremolo pedal or the last one you’ll ever need.

Chris is the co-author of Eruption - Conversations with Eddie Van Halen. He is a 40-year music industry veteran who started at Boardwalk Entertainment (Joan Jett, Night Ranger) and Roland US before becoming a guitar journalist in 1991. He has interviewed more than 600 artists, written more than 1,400 product reviews and contributed to Jeff Beck’s Beck 01: Hot Rods and Rock & Roll and Eric Clapton’s Six String Stories.