Fx block, if you're using it as a replacement for your amp/cab stuff, pretty much goes in the same place in the line-up as your amp. Wah, compressor, pedals, other kinds of pre-preamp stuff first (the usual stuff you put after your guitar, but before your amp), then the fx loop (when you're using either an outboard preamp or the preamp section of yur amp), then the delays, chorus, etc., then out to your noise making - power amp or return on the fx loop on your amp head or combo. The chart made by mrstrat just above your post shows it exactly. The second amp in the diagram is if you want your output to be stereo. So: signal flow for the 4CM - guitar, to AxeFX input, Axe-FX fx send (marked on the back), to amp front input, amp send (from it's fx loop), to AxeFX return (marked as such on the back), AxeFX out, to amp head return, amp head out to speakers. The loop on your amp has to be engaged, the fx loop in the AxeFX (as long as it is not bypassed) routes the signal to/from your amp's preamp section. Super simple - only three/four hours of head scratching, feedback, choice obscenities, eventual manual reading and re-reading, in addition to reading all the on-line stuff, such as my little word-festival. Volume balancing and control is another discussion, but don't forget to be sure everything has some volume up (7 or 8 o'clock, just to be sure you get signal), then - well, go for it. One of the benefits is you can mix/match, change the order, add and/or subtract stuff at will without a single cord, power supply, or rack. Downside - learning curve - and if you're here in the first place, you've got to know that's a part of it. Hope there's a little bit of help here.
