Class GH
UBUY has been the industry leader in Class G/H Amplifiers in the mobile marketplace.
Class GH Amplifiers have a more complicated power supply then a traditional Class AB amplifier. But that pays off in higher efficiency, especially with music. Resulting in smaller heatsinks, and lighter, more compact shipping weight. All while maintaining the sonic accuracy and feel of a Class AB amplifier.
Below are a couple of illustrations showing where the increase in efficiency is gained. By reducing the voltage on the output power transistors during normal operation, efficiency is improved greatly.
More Reading.
http://caraudiomag.com/articles/anatomy-power-amplifier
http://en.wikipedia.org/wiki/Electronic_amplifier#Classes_G_and_H