T-RackS Leslie: Rotary Speaker Effect Plugin by IK Multimedia

The module includes 11 Leslie models: five amps and six rotary-speaker cabinets. The Leslie 122 is a vintage unit from the early 70s, with a slightly warmer tone than the 122A. The 122A is a more modern model with a balanced amp input and a medium-tall cabinet. The Leslie 147 is a mid-60s vintage unit with no reflectors on the horns, which gives it a different character from the 122. The 3300w pairs a 300-watt RMS solid-state amp with a vacuum tube preamp. The G-37 and Studio 12 are compact dual-rotor designs, with the G-37 voiced for guitar and the Studio 12 aimed at keyboard players.

IK Multimedia uses Dynamic Interaction Modeling for the amps and Volumetric Response Modeling for the cabinets, which were recorded in a high-quality room to capture their real behavior.

The interface is split into three areas. The control panel has Setup, Amp and EQ pages. Setup covers mic distance, drum and horn rotation speed, and acceleration and deceleration, plus a spring reverb knob placed before the amp. The Amp page provides Gain, High-Pass Filter, Volume, Contour, Tube Drive and Tube Mode controls. The EQ page is a full parametric EQ.

The central area lets you choose amp and cabinet models and set mic positions at 90 or 180 degrees, which changes the perceived Doppler effect of the rotation. The mixer view gives level and pan control over the four microphone channels, so you can combine a centered mono drum signal with a stereo horn signal.