QUAD 99 Series - Manual (Page 3)

Since Peter Walker formed the company
in 1936, all Quad products have
displayed an originality in design, born
from a full and proper understanding of
every aspect of sound reproduction. A
world leader in audio amplifier and
electrostatic speaker design, Quad has,
over the years, made a major
contribution to the improvement of
sound quality. This contribution has been recognised by
awards from around the world including the Queen’s
Award for Technological Achievement in 1978.
Quad owners enjoy the confidence of knowing that the
complete system has been engineered to achieve optimal
performance, free from compatibility problems.
The history of Quad is one of technical achievement in
the field of sound reproduction. It is a story that 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.
A few years later, in 1953, the product which set the
standard for amplifiers was the Quad II power amplifier.
This amplifier pioneered the principle of cathode
coupling through the output transformer to reduce
harmonic distortion to almost negligible levels. Such was
its clear superiority that this model remained in
production for 18 years.
Three years later, in 1956, Quad demonstrated the first
true full-range electrostatic loudspeaker. This
remarkable product (known later as the ESL-57) used a
virtually mass-less plastic film as a moving diaphragm
between two charged plates. Compared to the
loudspeakers of the time, the ESL was free of unwanted
colourations and distortions. This product remained in
production, virtually unchanged, for 28 years.
A decade later in 1967 Quad introduced its first
transistorised amplifiers, the 33 Control Unit and the
303 power amplifier. These amplifiers introduced a new
‘Triples’ output stage that solved all the thermal
instability problems that plagued early transistor
designs. Radical in both circuit design and appearance,
they went on to win a prestigious Design Council Award
in 1969.
Amplifier performance took a further step forward in
1975 with the arrival of the Quad 405 ‘Current
Dumping’ amplifier. This remarkable new circuit
topology remains one of the few truly original amplifier
designs and has featured in Quad products ever since.
For this technology Quad was awarded the ‘Queen’s
Award for Technological Achievement’ in 1978.
In 1981 Quad announced the ESL-63; a full-range
electrostatic loudspeaker based upon two sets of
concentric annular electrodes fed through sequential
delay lines. This patented system produces a sound
pressure pattern identical to the theoretical ideal of a
point source origin. Once again a Quad Electrostatic
loudspeaker became the reference standard around the
world.
These are just some of the highlights from Quad’s
pedigree line of technological achievement. However, it
must always be remembered that Quad has never
indulged in technical ‘one-upmanship’. The technology
is there for a purpose – and that purpose has remained
constant over the years. To reproduce music in a form
that is the closest approach to the original sound.
The closest approach...
“It is so much better in terms of high fidelity, in its purest
sense. It reminded me how Quad retain an almost unique
grip on the concept.”
– Noel Keywood, Hi-Fi World
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