go to
http://www.guitargeek.com and have a look at some rigs to get some ideas...
Basically you can do almost anything you want! You can have many different preamps, FX units, eq units, etc and change all the ordering with a routing system!
As far as loops go, I find the extremely usefull. i have my preamp and FX unit in each other's FX loops, so I can choose where each effect goes in relation to the preamp, I also use it this way because it gives me the best sound, but with rack systems ther's a lot of experimentation to be done as to wjhere to put what, and it takes a while to get running, but it is fun...
(Edited by 7 Dying Trees at 12:27 pm on Oct. 5, 2001)