UltraVox achieves its sound by combining four (or six in version 2) specific algorithms. You can build this same chain for free using a combination of specialized plugins: UltraVox 2 Vocal Plugin - Leapwing Audio
While more comprehensive, Analog Obsession offers numerous "character" strips for free that can replicate the harmonics and air provided by UltraVox's algorithms. ultravox vst free
A highly-rated free vocal processor that focuses on ease of use and high sound quality for creators who need quick results. UltraVox achieves its sound by combining four (or