If anyone happens to know... if I wanted to put a switchable cab sim inside a DIY box (kind of like a less impressive Palmer PDI09) would I wire it as Input -> Cab Sim -> Active Direct Box -> XLR Out?
Yes, that's the order that I'd do.
Follow up question: in terms of switching the cab sim, would it make more sense to
1. run always-on power to the DI board and have a switch to turn power to the cab sim on or off?, or
2. to actually switch the cab sim board out, more like the switchable pre-boost wiring in the Offboard section?
#2 is what you'll want to do. If you kill the power to the cab sim but don't switch the signal route, your signal will die the moment it hits a dead opamp. Leave the power on, and switch around it like that pre-boost wiring you're looking at.
Q: Why is a drummer like a scud missile?
A: Both are offensive and inaccurate.