The history of Quad is one of technical achievements in the field of sound reproduction. Over the years the brand has amassed a large following as well as multiple awards for their innovations in the field. The company was founded by Peter J. Walker in 1936 in London, and was initially called S.P. Fidelity Sound Systems. In 1936 the name was changed to the Acoustical Manufacturing Co. Ltd. The company moved from London to Huntingdon in 1941 after being bombed out of London in World War II.

The company initially produced only public address equipment but after the war they began to produce equipment designed for use in the home as a result of the rising demand for high quality domestic sound reproduction. Within a few years the company had transitioned almost entirely to manufacturing models for the home audio market.

Their commercial success story began with the Quad 1 amplifier, which brought the benefits of 15 years knowledge and experience in professional audio and industrial products to the task of making the most accurate domestic audio amplifier of its age.

Following several successful products Peter Walker has become a very well-respected figure in the industry . His philosophy was perfectly encapsulated in his quote from December 1975 to ‘Wireless World’ magazine “An audio power amplifier is required to produce an output signal that differs from the input signal in magnitude only. It must therefore have occurred to every circuit designer that it should be a simple matter to take a portion of the output, compare it with the input to derive an error signal. It is then only necessary to amplify the error signal and add it to the output in the correct amplitude and phase to completely cancel the distortion of the primary amplifier.”

Peter put this principle into practice using two amplifiers per channel instead of one. The first stage ‘error’ amplifier is low powered but very high quality. The second amplifier is high powered, but of lesser audio quality as it is a lot more difficult to achieve very low distortion in high powered amplifier stages. Peter designed a way to compare the high powered output with the original audio input and derive the required error correction signal which is then injected into the audio path, in such a way that the high power audio output achieves a very low distortion figure, even at very high power levels. This innovative approach earned Quad the Queen’s Award for Technological Achievement in 1978.

Peter Walker was also attributed with the famous hifi quote “the perfect amplifier is a straight wire with gain” – the implication being that nothing would be added, and nothing taken away from the signal, just a bigger version of the same thing at one end. It was an aim, a goal, a description of the perfect amplifier – nobody, including Mr. Walker, ever said they’d attained that goal, and even if they did, the chances were that they were severely handicapped by their test equipment at the time.
The name “QUAD” is an acronym for “Quality Unit Amplifier Domestic”, used to describe the QUAD I amplifier. In 1983, when having become known for their QUAD range of products, the Acoustical Manufacturing Co. Ltd changed its name to QUAD Electroacoustics Ltd.