A.C (alternating current) amplifiers first became popular in the late 1920s when technology permitted, for the first time, enough electrical power to approximate the acoustic volume of an original musical performance with loudspeakers. Advancement was slow and it wasn't until the late 1940s, with the introduction of the long-playing record, that it became possible to widen the overall frequency range of recorded music so that a reasonable facsimile of the original could finally be attained. Improvements in broadcasting equipment and the introduction of FM (frequency-modulation) radio provided still higher quality, and by the early 1950s the general public had begun to develop an interest in 'high fidelity'.

Originally, the term high fidelity (or hi-fi, as it was later shortened to) referred to an assemblage of equipment (more often than not built by the hobbyist himself) designed for music reproduction with as great a faithfulness to the original as possible. Amplifier designs were published in Radio Magazines and equipment in 'kit' form was offered to the 'do-it-yourself' enthusiast. Early hi-fi systems were always mono, and usually consisted of loudspeakers which had been originally designed for movie-theatres and auditoriums, since speakers of high quality were rarely used in conventional radios. Amplifiers designed for public address systems were adapted for home use, but in many ways these early systems were makeshift and less than ideal.

The Williamson amplifer was probably the first 'true' high fidelity amplifier, the design of which was published in the spring of 1947 in "Wireless World". It soon became the benchmark for the many new amplifier designs that sprung up in the early 1950s and although Williamson never sold his amplifier commercially, many manufacturers produced versions of it. During the early 1950s it was quite common to see the name 'Williamson' being referred to in amplifier descriptions on both sides of the Atlantic.

Sufficient demand was recognised by the late 1940s to warrant the design, development and production of amplifiers, record-playing equipment and high-quality loud-speakers intended primarily for home-use, and by 1954 the industry had over 200 manufacturers engaged in building components in the USA alone.

By the time stereo burst onto the scene in 1958, amplifier designers were ready with stereo models. Some manufactures offered (for a short transitional period) 'Stereo Converters' for those already set up with mono equipment. These converters consisted of an integrated stereo preamplifier and mono power amplifer, the idea being to supplement the existing mono amplifer and speaker by simply adding the converter plus one other speaker.

Valve (or tube) amplifiers dominated the early stereo years, but by the mid 1960s they had been all but replaced by their solid state (transistorised) counterparts. The established British companies began to fall by the wayside, not being able to compete with the Japanese giants (Sony, Pioneer, Akai, Sansui etc) and in the United States, those that survived were quick to switch to solid-state technologies. By the late 1960s, valve hi-fi amplifiers were almost a thing of the past, although to this day valves have always been the technology of preference by electric guitarists and have constantly kept a majority market share.

In the late 1970s however, a 'rennaissance' of valve equipment began, fuelled by a few die-hard enthusiasts and aesthetes. New technologies and the retro look made the new generation of valve equipment extrememely appealing. By the late 1980s, companies like Marantz, McIntosh, Quad and Radford had even begun to reissue their classic valve models.

Today there is a very healthy interest in valve high-fidelity equipment, both new and old. This CD-ROM attempts to take you, the viewer, down memory lane for a glimpse of how things used to be.

... now read on!