Doepfer

I'm looking for effects units to voltage control with my Doepfer. Effects units that have a 
voltage control input? (something like the ADA Flanger that has a Voltage Control input 
jack) I like the idea of different kinds of equipment breathing voltages into one another. 
I'm having a difficult time finding units on the web.

I'm curious how many people do this and what units are out there that allow it? 

Thanks for your help,