How is your AC voltage in your basement?
Did you double/triple check that everything is hooked up right?
Could you have a bass boost or contour button pushed in that you don't normally have engaged-- could have bumped it in transport...
Could you have a battery in need of replacement somewhere in your signal chain?
I'm not trying to insult you, but all of these things have had me blaming innocent parties
Edit: Well, I don't type very fast.