Antares recently released Auto-Tune EFX+ ($199) the latest plug-in in its Auto-Tune EFX series. As in the previous version, Auto-Tune EFX 3, you get Auto-Tune vocal tuning, including the ability to create the warbly "Auto-Tune effect." It also improves the Auto-Motion feature, which lets you impose melodic patterns on vocals.
But the biggest news here is the addition of the Auto-EFX Multi-Effects Rack, which enables you to add doubling, tube distortion, pitch and throat effects (changing formants and more), mutate effects (ring modulation), filter effects, and vocoder effects.
Basically, this plug-in can do everything from fixing some pitchiness in a vocal, to changing its character, to turning a voice into that of a robot or alien.
The vocal tuning offers less parameter control than on Auto-Tune Pro but is still quite effective. In addition to setting the key, voice type and scale, you get knobs for Retune Speed, which when turned close to 0 (counterintuitively, its fastest setting) gives your vocals the Auto-Tune Effect. The manual recommends setting it between 10 and 50 for a more natural sound. You also get the Humanize control, which slows down the tuning speed on the sustaining part of long notes, which also helps keep things sounding natural.
The Auto-Motion feature is a melodic generator that imposes an arpeggiator-like rhythmic and melodic pattern on your voice from an extensive included library. This feature was in Auto-Tune EFX 3, but in EFX+ it adds an Auto mode, where the pattern is triggered by incoming audio.
The Multi-Effects Rack feature lets you run up to four effects at a time. Because there are six effects types, you choose a template from various combinations of the included effects in an assortment of orders. Once you have your four effects, you can turn them on and off individually, and you can edit two parameters for each using an XY Pad.
The effects are excellent. The warm-sounding Tube Amp effect lets you go from mild to heavy saturation. Pitch and Throat let you mess with Throat Length (changes the formants) and pitch. You can do stuff like turn a male voice into a female, and vice versa, turn an adult voice into a child, and so forth.
The Duet effect transforms a single voice into a stereo double (or mono if you're using a mono instantiation of Auto-Tune EFX+) and is useful for fattening up lead vocals or stereo-doubling harmony parts You get adjustable parameters for Time and Pitch difference on the XY pad, allowing you to tweak it as you like. You can use the Mutate and Vocode effects to create some otherworldly or robot-like effects.
Although I've only had a short time to mess with Auto-Tune EFX+, I like it a bunch. It's a multifaceted plug-in that gives you the ability to both tune and manipulate vocals. Although designed for voices, its Auto-Motion and Multi-Effects rack features can be used on other instruments. I tried the Tube Amp on a rhythm guitar and it sounded great. I also tried the Auto-Motion on a synth, with equally impressive results.