My Sunn has two effects loops, and I still just always put everything in front because I'm too lazy. Does it really make such a difference to put your delay and reverb in the loop? Yes, you'll want to put them after the dirt on your pedalboard. I've got my delay and reverb in front of the amp, the other guitarist in my band is going in the loop, but I don't think his necessarily sounds any better or different than mine. I'm curious to know why people started doing that in the first place.