A: The big one is that a stepped attenuator can easily repeat a setting with 100% accuracy. This is very difficult with a rotary or slider potentiometer. In some cases, the components used with a stepped attenuator (resistors) may be “cleaner” than a potentiomenter, which has a variable resistance that can introduce subtle artifacts — we want to emphasize the “subtle” in that statement, though. We’re not talking about a night-and-day difference, and in some cases there may be no difference. It depends on the application, the circuit design, and the specific components in use.