Convention Paper
Ultra Efficient Linear Amplifiers
AES Convention 142 · Paper 9736 · May 2017
Abstract
“Class-D” switching amplifiers are considered to be the most efficient amplifiers. However, designers must deal with supply rail, and radio frequency interference, and the need to switch power devices at high frequencies. Because of these, and other problems, not everyone wishes to use switching based technologies amplifiers. Unfortunately, linear amplifiers are significantly more inefficient than switching amplifiers under sine wave testing. However real audio signals spend much more time at low amplitudes than a sine wave. By changing the switch point for “Class-G” or “Class-H” they can have efficiencies that rival “Class-D” amplifiers producing the same output. The paper develops optimum switch points for both single and multiple switching points, with respect to the expected amplitude distribution of the audio.
