These power amplifiers operate with a conventional toroidal transformer power supply. The circuitry is completely balanced with a feedback of only 20 dB, resulting in a very fast power amplifier with only slight distortion. In particular, the rough, unpleasant sound associated with TIM distortion is suppressed. The amplifier has a Class A/B design, which means that the operating voltage changes depending on the signal level. This improves efficiency, considerably reducing the amount of heat generated by the amplifier. Superfast, high-performance bipolar transistors are used for the power amplifier. They are rated for three times the maximum power dissipation of the amplifier, thus providing an enormous safety factor. Short-circuit protection is therefore not required until there is a load of less than 2 Ω and a phase shift of 45 degrees due to reactive load. These power amplifier naturally features all of the other standard protection circuits, including a clip limiter.