The development history of sound technology can be divided into five stages: vacuum transistor, electronic tube, transistor, integrated circuit, and field-effect transistor.

Foldable transistor

In 1906, American De Forrest invented the vacuum transistor, pioneering human electroacoustic technology. In 1927, Bell Labs invented negative feedback technology, ushering in a new era in the development of audio technology. Representative examples such as Williamson amplifiers have successfully applied negative feedback technology, greatly reducing the distortion of amplifiers.

Folding electron tube

In the 1950s, the development of electronic tube amplifiers reached a climax, with various types of tube amplifiers emerging one after another. Due to the sweet and mellow sound of electronic tube amplifiers, they are still favored by enthusiasts to this day.

Foldable transistor

The emergence of transistors in the 1960s opened up a wider world for audio enthusiasts. Transistor amplifiers have the characteristics of delicate and moving sound, low distortion, wide frequency response, and dynamic range.

Foldable integrated circuit

In the early 1960s, the United States first introduced a new member of sound technology - integrated circuits. By the early 1970s, integrated circuits were gradually recognized by the sound industry due to their excellent quality, low price, small size, and multiple functions. Up to now, thick film audio integrated circuits and operational amplifier integrated circuits have been widely used in audio circuits.

Folded field effect

In the 1970s, Japan produced the first field-effect power transistor. Due to the combination of pure thickness and sweet sound of electronic tubes, as well as the dynamic range of 90dB and THD<0.01% (at 100kHz), field-effect power transistors quickly became popular in the audio industry. Many amplifiers nowadays use field-effect transistors as the final output.