As Submadreamgun said you can do it with a good preamp and a good DI. But there is a great solution for that matter, this box that combines booth for doing it very easily during live gigs : http://sub-continental.com/dd/bodyplug.html

Here's how to plug your setup : http://sub-continental.com/dd/modules/bodyplug/bodyplug.pdf

It combines a high-end class A preamp with a good DI, and you can blend dry vocals and effected sound, also has a true bypass (which is not often the case with digital vocal processor, ask live techs), every live sound engineer who dealt with the bodyplug was happy with it. The quality of the preamp even improves the vocal sound on most mixers.

As Submadreamgun said you can do it with a good preamp and a good DI, but there is a great solution for that matter, this box that combines both for doing it very easily during live gigs : http://sub-continental.com/dd/bodyplug.html

Here's how to plug your setup : http://sub-continental.com/dd/modules/bodyplug/bodyplug.pdf

It combines a high-end class A preamp with a good DI, and you can blend dry vocals and effected sound, also has a true bypass (which is not often the case with digital vocal processor, ask live techs), every live sound engineer who dealt with the bodyplug was happy with it. The quality of the preamp even improves the vocal sound on most mixers.