Component of all electronic devices used to transform the electrical power supplied through a wall outlet into power the electric component can use. The capacity of the power supply is measured in watts. enerally, a well designed, powerful power supply benefits audio/video components by providing sufficient clean power to operate at peak efficiency and highest quality. Power supplies are of particular importance to amplifiers, which need large amounts of power to drive speakers. he power supply consists of three parts, the transformer, the rectifiers, and the capacitors. The most commonly used transformer is the toroidal transformer. Its job is to collect power from the wall outlet and convert it into a voltage useable by the amplifier’s other circuitry. Typically, a well built power supply must include a very large, heavy transformer capable of large power output (this is one reason heavier amplifiers tend to be better quality with better power supplies though weight is certainly not the defining factor in amplifier testing). The toroidal transformer generates low hum and noise making it a widely used power supply feature. he power output by the transformer is passed on to the rectifiers. The rectifiers change the alternating current to direct current (electricity carried through the walls and over electric lines is alternating current meaning that it swings from positive to negative at a certain frequency; direct current is steady with no alteration and is used in batteries). The power is then passed on as direct current to the capacitors. apacitors store energy for later use and eliminate residual noise in the voltage. When the amplifier’s circuits need power to amplify a signal and output it to a speaker, they draw the power from the capacitors. A good power supply should have a large total capacitance (measured in microfarads in amplifiers) in order to store a large amount of power. he power supply is one of the most important pieces of an amplifier along with the amplification devices (typically bipolar or MOSFET transistors). Without a well-designed and powerful power supply, an amplifier does not have the ability to output large amounts of power to the speakers. All exceptional amplifiers are built around exceptional power supplies. No amplifier with a poor power supply can provide quality power or sound. ypically, mono amplifiers (amplifiers with a single channel of output) are able to provide the ultimate in audio reproduction (all things being equal – a cheap mono amp will not equal an expensive, well-designed stereo amp) because they enjoy their own power supplies not shared with any other channels. In the same vein, integrated amplifiers and receivers in particular often suffer from lesser quality amplifiers due in no small part to the fact that in most cases their amplification sections must share a power supply (and often not an optimally designed supply at that) with multiple other sections. R>