Pete Shambler has made a nice video demonstrating the Doepfer A-172 Minimum/Maximum Selector module.
In the video he shows some of the ways he tends to use it... pretty interesting...
" Five quick patches with the Doepfer A-172 Max/Min utility module. The first three are in stereo, so headphones are recommended!"
More info at http://www.theshamblers.blogspot.nl/
,and find more about the A-172 HERE