Developer Eventide posted an official overview for their newest effect to come to AUv3 and VST.
Spring Reverb models the sound and character of popular spring reverbs found in guitar amplifiers, popularized by Surf, Garage and Rockabilly music. Spring takes this a step further by allowing manipulation of physical parameters not normally available in a real spring tank. The results vary from faithful recreations of real springs to distinctive new sounds that push the physical boundaries of reverb. Now available for your desktop and iOS devices.
Visit http://eventideaudio.com/Spring to learn more.
Subscribe to the Eventide channel for more demo videos and tips https://www.youtube.com/EventideAudio