There are very few pedals that are designed to take AC voltage (vs. DC voltage). If you feed your 9VDC (battery voltage) pedal AC, it usually will destroy much of the electronics. Once in a while, the pedal will survive, needing only minor repairs. However, most of the time the entire circuit board needs to be replaced. If you have an AC powered pedal on your pedalboard (Line 6 DL4 for example), be very careful to not plug the AC adapter into any of your other pedals… not even for a few seconds. Always look at the adapter label for the Output Voltage and make sure it’s 9VDC, not AC, before you plug it in…or just get a 1 SPOT and put your other adapters away!
The V2 and V3 Series pedals from Truetone include an AC blocking component that will prevent AC voltage from damaging your pedal.