ABSTRACT
The domestic amplifi er is unlikely to be operated at high output levels for a signifi cant length of time, and the power supplies are often therefore designed to deliver high currents for short periods to take care of short, loud passages. A power supply big enough to supply high currents for lengthy periods is probably wasted in a domestic amplifi er. Also, the thermal inertia of the transformer and the heat sinks means that unacceptable rises in temperature are unlikely. Although there are one or two domestic speakers which are notoriously diffi cult to drive due to various combinations of low impedance, low effi ciency (leading to high power demand), and wide phase swings (current and voltage being out of step with each other due to crossover components and driver behavior in a particular speaker enclosure), the majority of domestic hi-fi speakers are a comfortable load for an amplifi er, and usually the speaker leads will be less than 10 meters in length.
