Dan converts regular pianos into player pianos for a living. He wants to know how he can make sure he isn't drawing too much amperage or wattage and damage the power device. How can he prevent that? Leo says that in general, a power brick won't work if it doesn't match the wattage. Leo says that watts are volts times amps. So watts are where he'll want to be careful. So take the volts and multiple by amps, and see what voltage it can take. Both should be on the power supply or adapter.