Eventide DSP 4000 Digital Effects Processor Ultra Harmonizer (used)
Eventide DSP 4000 Digital Multi Effects Processor (used)
The Eventide 4000 series Ultra-Harmonizers are multipurpose programmable digital audio signal processors with pitch change capability. They are considered by some to be the greatest in a line of pitch changing special effects units stretching back to before most audio manufacturers ever heard of digital.
The 4000s are capable of creating effects you've never heard before, with built-in patch editor to let you create your own effects algorithms.