I'm not sure what to tell you, other than making sure all your levels are set right. Double check everything to make sure that the Deltafex is receiving a good signal, make sure that the mix knob on the deltafex isn't set all the way to dry, make sure the deltafex's output level is up, make sure the amp's level is up. If used in an effects loop with a send and return make sure that the send and return levels are up. If all the levels are set right, and you still get no sound from the Deltafex, it's time to contact Peavey. They've alway's been good about getting back to me with helpful information. Or, you could look around on their forum for some advice >here<.