We are all aware that electricity is needed to operate an audio amplifier. We casually say that we cannot get something for nothing. We pay the electric company an amount that is based on the number of kilowatt-hours of electricity used. In fundamental physics terms, electricity is a form of energy that is needed to power and operate an amplifier. The expenses of the electric company include the production of electrical energy from other forms of energy and the transmission of this form of energy from the electrical generator plants to your home.