BOSS VT-1 Voice Transformer
The VT-1 Voice Transformer is like a simple modern-day Vocoder + Harmonizer and then some! Its purpose is to alter the human voice, ideal for DJ's, techno, and other creative uses. The VT-1 will perform such effects as de-tuning, +/- 1 octave pitch shifting, formant shifting and it has built-in digital reverb. There are four prominent sliders for the aforementioned effects. And the Robot button does in fact produce a somewhat vocoder-like sound by fixing the pitch of your voice and fuzzing it. Using the Robot effect in conjunction with the formant and pitch sliders can get some pretty weird vocoder sounds.
The VT-1 has mic-input with adjustable trim level so you can run your voice, or get creative and feed loops and sounds through the VT-1 and transform away with this affordable and simple table-top effect unit. The VT-1 also has its place in professional broadcast work. It can be used to adjust the pitch or even the gender of a person's voice and still sound natural. Or use it to thicken up or harmonize a vocal track for a jingle or commercial track. It's fun, colorful, easy to use, economical and can be quite a useful source of unique effects and sounds, if you're into this sort of thing! Apollo 440 used it for all vocals on "Stop the Rock".