That type of circuit may not like certain pedals in front of it.
definitely experiment with your order - in my experience any pedal before it it doesn't work out well because of the super sensitive input. it is set up on the board so my bridge pickup goes directly into it - then it goes directly into an amp. i mute by switching to neck pickup only.
this is definitely true. i wouldn't give up the interaction between guitar volume/pedal input by putting a pedal before it either. maybe a passive volume pedal, if that, to control it with feet.
I'll have to keep these things in mind. Most of the play time I have had with it thus far has been without the rest of my board. I do really like the speaker cranker in front of it, but I have much experimenting to do. As it stands, I have the speaker cranker and a Rat in front of the Cthulhu. Though that may change, Cthulhu will stay.