The audio power amplifier plays an essential role in every system that generates audible sound. For decades, amplifiers have been produced using analogue (Class A and AB) designs, which are very inefficient and result in voluminous, heavy and rather expensive products. The innovation cycle of analogue audio power conversion has come to its maturity and hardly any innovation can be made there.

On the other hand, switching or Class D amplification techniques are only at the beginning of their development. These technologies carry a large potential for delivering much higher efficiency and audio performance, making audio products more reliable, of higher quality, smaller size, and involving lower costs.

Instead of linear power regulation used in Class AB amplifiers, which leads to energy losses in power transistors, Class D amplifiers use switching transistors that operate only at two stages – “on“ or “off. Nearly no energy loss occurs at the transistor and nearly all the power is carried to the transducer.

Class D technologies have been around for decades, but until the 1990s their design and integration characteristics have not been developed to the level necessary for achieving high performance in quality audio and Hi Fi applications. It is only in the 1990s that the semiconductor and digital technologies have been developed to enable enhancement of Class D technologies. We have pioneered in developing new technologies to enhance Class D amplification and bring the audio quality to the level accepted by audiophiles. This allowed for subsequent introduction of Class D technologies into a wide range of audio applications.


ICEpower® Class D amplifiers have the following advantages:

    •  Audio performance on the level with or better than Class AB amplifiers

    •  Significantly higher energy efficiency of audio products

    •  Audio products can be made much smaller and lighter, external heat sinks can be eliminated

    •  Significantly decreased manufacturing costs

    •  Higher integration of components is possible

    •  Resulting in more design freedom and more attractive products

    •  Due to the possibility of designing smaller products, more channels can be integrated into a
       single solution or audio product
      
    •  Higher quality of products

    •  The possibility of increasing the standard of existing products

    •  All of this taken together benefits our environment in numerous ways and makes Class D
       amplification a “green”  technology   

For examples, the 10-channel solutions that ICEpower has created for Pioneer Electronics’ Susano A/V receiver could not have been developed without applying switching technologies – Class AB amplifiers could not sustain this amount of channels with high audio quality in a single product. 

 

Below is the graph of an ICEpower amplifier efficiency compared to the highest theoretically possible efficiency of a Class AB amplifier (the latter calculated under ideal conditions which can never be achieved in reality):

 

                     Green graph: actual measured efficiency of the ICEpower Class D amplifier
                     Conditions: mains 230V AC, load 8 Ohm, frequency 1 kHz sine, 1 channel driven
                     Red graph: the best theoretically possible efficiency of a Class AB amplifier 

 

Vice versa, below is the graph of energy loss in an ICEpower Class D amplifier vs. power loss in a Class AB amplifier with the best theoretically possible efficiency.



                     Green graph: power loss of an ICEpower Class D amplifier
                     Conditions: mains 230V AC, load 8 Ohm, frequency 1 kHz sine, 1 channel driven
                     Red graph: power loss in a Class AB amplifier with the best theoretically possible                      efficiency