Vocal DIY Effects?

[Marcos - Munky]

The octave circuits generate a octave up (or down), but don't filter the original note. The whammy looks like a giant bend (or whammy bar, I think this is the origin of the name), the original note is filtered, only the octave up or down note is heared. In Mark Hammer's site, you can find a octave divider schematic that have a mix pot, maybe this will work if you use the mix pot to get only the octave note.