Quad 99 Series Manual Do Utilizador

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

3