Class H Power Amplifier Output Stage

Class H Power Amplifier Output Stage

No-compromise audio performance with improved efficiency

It is useful to expand Class AB amplifier technology with “Class H switching”, especially high output power amplifiers. This idea seems to be very simple at first sight. The AB amplifier is provided with an additional power supply unit operating with half the voltage. As long as the power amplifier does not require a high output level - which is the case for most applications, especially fixed installations - it is supplied by the lower operating voltage, thereby significantly reducing power loss. Signal peaks are detected immediately and the Class H power supply dynamically takes over the provision of high voltage by means of a superfast field-effect transistor (FET), see diagram 1. Any potential switching artifacts are perfectly regulated by the high operating voltage suppression of the semanpro Class AB amplifier kernel. Like all semanpro amplifiers, Class H power amplifiers can be operated in bridged mode, are 2-ohm stable and are equipped with high-quality output relays. Electronic protection circuitries and associated protection algorithms constantly monitor the operational condition, reliably protecting the connected loudspeakers and the power amplifier if necessary. A comparably low permanent voltage strain of the kernel components, minimum thermal power loss and the associated positive affecting on all reliability parameters make semanpro's Class H power amplifiers the ideal choice for a permanent operation for example in fixed installation applications.