LEGACY OF THE TUBE AMPLIFIER

The first audio amplifier was invented just two years after the invention of the original rectifying diode thermionic valve in 1904. In 1906 American inventor, Lee de Forest known as the “Father of Radio” invented the three element triode vacuum tube and thus, the first amplification device. Lee de Forest held over 180 patents and his engineering advancement of the vacuum tube led way to countless applications. He was responsible for the first AM radio, greatly improved long distance telephone line transmissions as well as adding sound to motion pictures.

Effectively all forms of electronic amplification were originally developed utilizing the three element triode valve – vacuum tube. The diode thermionic valve passes current in one direction and is primarily used to rectify AC voltage to DC. By addition of the third element the triode valve can regulate the flow of current by modulating voltage to the third element, otherwise called the control grid. Simply put, advent of the triode vacuum tube made electronic amplification for numerous applications possible.

For over a fifty year timespan virtually every electronic consumer product was built with vacuum tubes. Radios built with valves and built-in audio tube amplifiers became a trend first in the 1920’s. This was a growing consumer trend until the 50’s when transistor radios emerged and subsequently replaced the more bulky and heat producing tube-style radios. Tube amplification was an integral aspect of technological achievement in loud speaker systems, radio broadcasting, telephony and scientific research for many decades after the advent of the vacuum tube, considered the dawn of modern electronics.

The “golden age” of valve tube technological achievement began during and after the close of the second world war. Prior to the war valve tube amplifiers were constructed of a common circuit topography, the single ended triode gain stage – Class A mode. The war itself drove further development of vacuum tube technology in various military intelligence applications. The post war affluent American society fostered an increased consumer demand for radio, hi-fi and later television consumer products – all based upon vacuum tube technology.

The term, hi-fi became a generic term for home audio equipment in the 1950’s. In this phase 33RPM records were beginning to replace 78RPM records and stereo was gradually replacing mono as a standard of high fidelity sound. All hi-fi amplifiers were tube-type until the 60’s when silicone transistor amplifiers started being favored for their compact size and reduced heat output and because American consumers historically are prone to change in trends and always wanting the latest in technology.

Manufacturing of vacuum tube-type home stereo components experienced a very sharp decline through the 70s and became nearly extinct in the 80s with the advent of the digital age. The term ‘hi-fi’ as a generic term to describe home audio systems was replaced with the term, ‘stereo’ during this phase too – perhaps rightly so.

Only professional guitarists who knew better, a handful of audiophile die hard enthusiasts and the Japanese keep the craft and science of tube amplifiers alive through this otherwise cold and harsh era of digital music and sound. Modern audiophiles and enthusiasts of truly high fidelity sound quality should take a moment of silence in respect of the Japanese audio enthusiasts who led us back to tube amps as a main staple of acceptable listening standards. Japanese component manufacturers never stopped manufacturing tube-type amplifiers. American Tube Amp offers a formal note of appreciation to our friends in Japan for carrying us through and delivering us out of the dark tunnel of the initial digitized sound era. Thank you, Japan!

We are also happy to acknowledge our neighbors in Russia for retaining use of the vacuum tube throughout the cold war. The Soviets were aware of the valve’s ability to withstand nuclear detonated instantaneous overloads that will destroy a transistor. If you have ever replaced a Russian made tube in a music instrument component like a preamp with let’s say, a low-noise Mullard 12AX7 then you know first hand how the Russian tube you removed is truly built like a tank and actually a much sturdier construction than the British made Mullard tube.

But Americans are not known to sit idly and watch the world go by. Though the only vacuum tubes produced today are made in Asian and Eastern European countries, in the past two decades we have seen the emergence of some very fine and respectable hi-fi tube amplifier manufacturers on American soil that American Tube Amp is proud to join ranks with. With the comeback of vinyl records and tube-type amplifiers enhanced by modern improvements, today we can safely say that the term high fidelity is again common among us and that we as a community have achieved new levels in audio performance and sound quality.