#1
i bought a crate amp and i had an older (yet decent quality) effect pedal. i was screwing with it Monday and it wouldn't work, i was just getting a LOT of fuzz through the amp.

its a crate 65 watt flexwave amp with built in effects. was it just because the pedals are compatible with the amp? or is it just my dumb fault for a faulty connection job?
#2
probably your pedals are not compatible, all my pedals never would work on my spider amp lol, so i got ride of it...best decision of my life
#4
Pedals can't be incompatible with amps---either ur pedal is shot, your cable is shot or your amp is shot. Most likely cable or pedal. Try using it on a different amp and see what happens--use a friend's if you dont have another one.

What pedal is it btw?
#5
a lot of amps with digital effects or even digital amps dont really like pedals in front of them. i dont really have a better answer for why other than just because they dont like one another.

that said, it should still work. i would try your connections to make sure everything is correct before you go tossing out something.
#7
Maybe interference from an electrical device in the same room as your guitar and amp?