diyelectroniclab

  Jean Hiraga is a renowned figure in the world of audio, particularly known for his influential Class A amplifier designs, which were first published in the French audio magazine l'Audiophile in the late 1970s and early 1980s. His most famous designs are "Le Monstre" and the "20W Class A" (later a "Super 30W Class A"). These amplifiers, while relatively low in power output, are highly regarded by audiophiles for their exceptional sound quality. The key principles behind Hiraga's designs are simplicity and purity of the signal path. He believed that quality takes precedence over quantity (power) and that a minimalist, well-designed circuit with high-quality components and a robust power supply would produce a more natural and musical sound.

  The JLH Class A amplifier, designed by John Linsley Hood in 1969, stands as a classic and enduring example of a simple, high-fidelity audio circuit. It operates in pure Class A , meaning its output transistors are constantly conducting a significant amount of current, even when there's no input signal. This constant current draw eliminates the crossover distortion that can occur in Class B or AB amplifiers, resulting in a smooth, warm, and highly linear sound that many audiophiles find exceptionally pleasing. While its low efficiency generates a lot of heat and requires substantial heatsinks, its straightforward design and excellent sound quality have made it a popular choice for hobbyists and a foundational circuit in the history of audio electronics.