Some of the most iconic tones ever recorded involve the sound of the Leslie Rotary Speaker. A staple sound for jazz, R&B, gospel, and rock music, the Leslie speaker was invented by Donald Leslie in the late 1930s to give the Hammond organ a more expansive sound similar to a pipe organ. Leslie’s design used a spinning horn for treble frequencies and a spinning 15” drum for bass to create a rich, vibrato-like sound via the Doppler effect. Rock guitar players also gravitated to the sound, and in 1968 the Univibe pedal unleashed a swirling sound close enough to a Leslie that Jimi Hendrix, David Gilmour, Davey Johnstone, and Peter Frampton quickly embraced it. Leslie speaker cabinets can weigh well over 100 lbs., so a guitar and keyboard pedal version was a welcome alternative.
Over the decades there have been dozens of effects pedals that have emulated the famous Leslie sound. Enter the BOSS RT-2 Rotary Ensemble. BOSS, one of the most popular and successful effects pedal companies since 1976, and famous for its CE-1 Chorus Ensemble, is no stranger to modulation effects. MC received and tested their new RT-2, and quite simply, this may be the best sounding emulation of a Leslie speaker to date. Usable in stereo or mono, it sounds spectacular and is extremely versatile.
The RT-2’s three-position mode switch selects the classic rotary speaker voice and two modern variations. Mode I is a modeled reproduction of the most famous vintage Leslie 122 rotary speaker design. Mode II is also the vintage rotary sound, enhanced with a wider tonal range. This mode provides increased spatial performance when paired with overdrive and distortion pedals. Mode III provides enhanced definition for soloing and has a separate tube saturation drive control dial.
A hallmark of the Leslie sound is the ability to speed up and slow down the rotors to achieve emotional vibrato and tremolo tones. The RT-2 enables this in real time in several ways. Four selectable pedal switch modes for controlling the rotor speed can be toggled by holding the bypass switch down when the effect is on. For more precise control of the speed, an optional BOSS Expression Pedal can be connected for all the in between speeds. For some users, the ability to precisely control the speed is an essential feature. An optional BOSS footswitch can also provide brake control. A virtual rotor display the size of a penny lights red and blue to indicate treble and bass rotor speeds. A Rise/Fall Time switch adjusts the transition time between rotor speeds and a Drive/Balance switch assigns the Drive knob to control the saturation amount or the volume balance between the treble and bass rotors.
The RT-2 can be powered via an optional BOSS 9-volt adaptor or 9-volt battery. For a look at even more features and an informative video, check out the Boss website. Exclusive members-only services and support from the free Roland Backstage website is available with your purchase. A must have for musicians who love a great Leslie sound. $239.99
