background image

‘the closest approach to the original sound...’ has been a 
Quad philosophy since 1936. More than just a slogan, it 
underlies the company’s commitment to producing the 
finest audio equipment, capable of reproducing all the 
elements and emotion of a live performance.

This  is  a  faithful  reproduction  of  the  original,
the  new  Quad  II  Classic  offers  audiophiles  the 
chance  to  recreate  the  spirit  and  atmosphere 
produced from one of  the most famous amplifiers 
in audio history.

The original Quad II was first launched in 1953, 
designed by Peter Walker. At the time, many of 
his  contemporaries  were  also  producing  good 
quality valve amplifiers. The Quad II looked, in 
comparison,  very  simple  and  unassuming,  but 
its  performance  was  far  beyond  that  which  its 
diminutive dimensions might suggest.

The property which set the Quad II amplifier apart 
from other amplifiers of the time was its output 
stage.  It  was  arranged  such  that  the  cathode 
coupled  circuit  emulated  the  performance  of 
triode operation, but with the size and efficiency 
characteristics of pentode operation. It was this 
breakthrough  that  ensured  the  Quad  II  was  to 
remain in continuous production until 1970.

Peter’s  circuit,  notably  the  design  of  the  output 
transformer, has become the stuff of legend amongst 
electronics  engineers.  Studied  and  analysed  by 
the  finest  minds  in  the  industry,  the  elegance 
and coherence of the design is still regarded as a 
reference today.

Given the quite modest components of the day, he 
was  able  to  engineer  something  which  was  quite 
literally greater than the sum of its parts.

The Quad II classic has been recreated accurately 
with output valves and input valves the equivalent 
of  those  used  in  the  original  design.  The  same 
balancing act has been employed to ensure the same 
wealth of detail and gentle tone of the original.

The output valves produce around 15w per channel, 
operating  in  Class  A    which,  although  slight  by 
modern  standards,  allows  a  gloriously  sweet 
and  refined  sound  with  appropriately  matched 
contemporary loudspeakers.

II-classic

The Quad

17

16

Summary of Contents for Vacuum Tuber Amplifier Systems II-FORTY

Page 1: ...the closest approach to the original sound s e r i e s VACUUM TUBE AMPLIFIER SYSTEMS C l a s s i c...

Page 2: ...ower amplifiers use a circuit dating back over fifty years to the time when vacuum tubes ruled the electronics industry and Peter Walker considered by many to be the master of audiophile design He oft...

Page 3: ...ring build quality finesse and refinement Quad products have always been amongst the finest au dio products in the world When Peter Walker started making com mercial PA systems in 1936 few could have...

Page 4: ...l cathode loading in the output transformer This method reduces distortion when compared to the usual Ultra Linear or triode methods however it does require a greater grid driving voltage This is achi...

Page 5: ...9 8...

Page 6: ...s hard wired to the circuit and has an estimated life of nearly 100 000 hours Together with transformers designed by one of the World s leading authorities and relay input switching the musical signal...

Page 7: ...e total line gain is 15dB with a high quality potentiometer controlling the output levels Reminiscent of the original QC 22 control module there is a simple balance control allowing for variation from...

Page 8: ...he QC 24 phono stage which allows direct connection of a turntable with an internal switch to change between moving coil and moving magnet cartridges This can be fitted as standard or added later For...

Page 9: ...thode coupled circuit emulated the performance of triode operation but with the size and efficiency characteristics of pentode operation It was this breakthrough that ensured the Quad II was to remain...

Page 10: ...that has been experienced by generations of Quad enthusiasts 1 x 6111 twin triode 0 2 0 02 1W 5Hz 50kHz 0dB 0 5dB Better than 80dB 15dB 50k ohms 5 x Line level 2 x Buffered tape loops Model QC twenty...

Page 11: ...n Court Ermine Business Park Huntingdon Cambs PE29 6XU Tel 01480 447700 Fax 01480 431767 www quad hifi co uk The information in this brochure is subject to change without notice All rights reserved 20...

Reviews: