The power supply you use with your MTH Protosound 2/ 3 equipped trains (and with your DCS Control equipment like the TIU) is important for two reasons:                     1) Possible control issues/malfunctions with the engines and                      2) Possible actual damage to the electronics.                                  (Note:  You can damage your train electronics with too high a voltage or with PWM(Pulse Width Modulated) voltages of a high enough voltage spike frequen