Multi-channel effects loop with feedback

[DallasoftheDead]

Hey guys, sorry for the long post. Just got into building pedals recently and I'm still having quite a time wrapping my head around some of this stuff.

I recently built this feedback loop pedal (http://68.media.tumblr.com/tumblr_lfwjj510Ya1qemwmy.gif) and really enjoy it, but now I'm thinking about expanding on it and adding more channels, but this seems like it might be a bigger endeavor than I thought at first. My first though was I could just piggyback connections from the in/out to each adjacent fx send (I'm planning on having three seperate effects loops, so three different send/return pairs for each), but the switching is where I've run into some problems, because I also thought I'd be able to piggyback connections on each of the 3pdt's, but then I realized that I would have to turn each one on and off seperately if they were all just daisychained together. I'm looking to be able to hit each footswitch and go to that effects loop, and possibly have a master so all channels could be activated as well. Each send/return doesn't necessarily need their own feedback loop, I was thinking maybe just on the master? Any help would be greatly appreciated here, thank you!