Originally Posted by GentleBen
I was thinking about adding some flanger or phaser to my voice like ZZ Top and wondered if I could insert a guitar pedal into the mixing board
That sort of thing is better done with an outboard rack unit, such as a Yamaha SPX990, Lexicon PCM90, TC M One or any similar box. Guitar pedals are designed with low level high impedance signals in mind. Rack gear is designed to handle the line level low impedance signals encountered with mixers. Plus you get multiple effects & many available presets in a rack device.