An ultrasonic unit manufacturing system and process are based on a universal ultrasonic generator unit that operates interchangeably with either one of piezoelectric and magnetostrictive ultrasonic devices, and optionally as well as with either on-off or power level control footswitches. The ultrasonic units use a generator unit having a detector that determines whether the connected device is piezoelectric or magnetostrictive, and activates the generator for the appropriate piezoelectric or magnetostrictive operating mode. The ultrasonic units so made and methods of using them are also disclosed.