Leslie Effect recreates the sound of a rotating-speaker cabinet: a spinning high-frequency horn and a low-frequency drum baffle, each with its own motor inertia. The plug-in models the three ingredients that make the effect musical — amplitude modulation as each rotor sweeps past the microphones, Doppler pitch modulation from the moving sound source, and true motor inertia: switching speeds ramps smoothly, with the horn spinning up in about a second while the heavy drum takes several.

A tube-style drive stage, adjustable 24 dB/oct Linkwitz-Riley crossover, virtual microphone distance/width and independent horn/drum controls extend the classic cabinet into modern sound design. Primary use cases: guitar, saz, bouzouki and keyboards/organ — plus vocals, synths and mix-bus motion.

Features

Dual-rotor engine — independent horn and drum with SLOW / FAST / BRAKE motor states and per-rotor speed, ramp, depth and level controls
Tube-style drive stage with loudness compensation, before the rotors
Adjustable crossover (200 Hz – 2 kHz, 24 dB/oct Linkwitz-Riley) splitting drum from horn
Doppler pitch modulation, virtual microphone distance and stereo width
47 factory presets in 9 categories — Essentials, Keyboard & Organ, Guitar, Saz & Bouzouki, Vocals, Synth & Keys, Sound Design, Mix & Bus, Extreme — plus renamable user presets
MIDI Learn on every control via the standard Rona right-click menu; mappings follow the plug-in across formats and the standalone app
Analogue-style VU meters with tube-style amber warm-up and cool-down
All 20 parameters host-automatable under stable IDs; click-free bypass and preset changes
Zero latency at all settings, 44.1 – 192 kHz, mono→mono / mono→stereo / stereo→stereo
Online activation with a privacy-preserving machine identifier; 3 computers per serial, managed in RONA License Manager

Great things are on the horizon