MUK series power amplifier belong to class H which is a lightweight and space-saving power amplifier, ideal for use in high quality touring sound systems as well as in demanding permanent installations. Heat and cooling are fundamental problems in many extreme high power amplifiers similar to the class H. In 2006, we launched a high efficiency class H amplifier. This development was an evolutionary step past the class D amplifier. class H obtains the same high efficiency as class D, while avoiding the main drawbacks. class D has a power-amplifier topology using Pulse Width.