A “Class H” amplifier is a type of audio amplifier that combines characteristics of both Class AB and Class D amplifiers to achieve efficient and high-quality audio amplification. Class H amplifiers are known for their ability to deliver power efficiently while maintaining low distortion levels. Here’s a brief overview of how Class H amplifiers work and their key characteristics:
- Class AB and Class D Hybrid: Class H amplifiers use a combination of Class AB and Class D amplifier technologies. Class AB amplifiers operate as linear amplifiers, which means they are relatively efficient but generate more heat when operating at higher power levels. Class D amplifiers, on the other hand, are highly efficient but can introduce some distortion, especially at lower power levels.
- Voltage Rails: The distinguishing feature of Class H amplifiers is the use of multiple voltage rails. Instead of operating at a fixed voltage level, Class H amplifiers dynamically adjust the voltage supply to the output stage based on the input signal’s requirements. This allows the amplifier to track the audio signal’s amplitude and provide higher voltage (and therefore more power) when needed and lower voltage during quieter passages.
- Efficiency: Class H amplifiers are prized for their efficiency, especially in applications where power output varies widely. By adjusting the voltage supply to match the audio signal, they waste less energy as heat, making them more energy-efficient compared to traditional Class AB amplifiers.
- Reduced Heat Generation: The dynamic voltage adjustment in Class H amplifiers helps reduce heat generation, which can be a concern in high-power amplifiers. This feature allows for smaller and more compact amplifier designs without the need for excessive cooling.
- Improved Linearity: Class H amplifiers aim to maintain the linearity of Class AB amplifiers while offering higher efficiency. This results in lower distortion levels and cleaner audio reproduction, making them suitable for applications where high-quality sound is crucial.
- Applications: Class H amplifiers are commonly used in professional audio and live sound reinforcement systems, as well as in high-end consumer audio equipment. They are well-suited for powering speakers in various settings, from concert halls and theaters to studio monitors and home audio systems.
In summary, Class H amplifiers are a hybrid design that combines the efficiency of Class D amplifiers with the linearity and low distortion characteristics of Class AB amplifiers. They are valued for their ability to deliver clean and efficient audio amplification while minimizing heat generation, making them a popular choice in both professional and high-quality consumer audio systems.
