QUAD Vacuum Tuber Amplifier Systems QUAD II-FORTY User Manual
Page 10

Quad sound systems have always provided
high levels of listening pleasure to their owners.
our philosophy has always been one of repro-
ducing the ‘live’ experience in the comfort of
your own home.
Whilst many modern amplifiers are stunningly
accurate and offer breathtaking resolution and
distortion figures in tiny fractions of a percent,
many also loose sight of the overall aim - which
for Quad, is to bring pleasure to the listener by
recreating the entire range of sensory experi-
ences felt at a live performance.
For many audiophiles, just as vinyl will never
be truly replaced by digital music, the vacuum
tube communicates on an emotional level that
can never really be surpassed by a transistor
based design.
The Quad II classic is one of the finest of these
vacuum tube amplifiers. Although small in di-
mension and modest in design, the purity with
which it conveys, not just the musical score, but
the sense of space; the passion of the vocal and
the range of textures from the instruments in any
performance, is without peer.
As a piece of audio history, the Quad II circuit
was pivotal in creating what we know of as genu-
ine ‘hi-fi’ today. As a design statement, the Quad
II is not only as relevant today is it was over fifty
years ago, it is remarkable in its absolute longev-
ity. Yet the only important factor is that the Quad
II Classic can bring the same pleasure to today’s
discerning customer 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-twentyfour
4 x 6111
‹0.08% (A-weighted)
20hz–20khz (+0dB/-0.5dB)
Better than 60dB
47Ω
10Ω
1.3mV (MM)/130uV (MC)
2.6mV (MM)/260uV (MC)
5.2mV (MM)/520uV (MC)
1.0
Selectable MC/MM cartridge
1 x fixed line level
1 x variable line level
15 VA maximum
QC-twentyfour P
Valve Complement
Thd @ 1V RMS
Frequency Response
hum and Noise
Line Stage Gain
Recommended Min. Load
Inputs
Valve Complement
Thd
Frequency Response
hum and Noise
Input Impedance
Moving magnet
Moving coil
Stage Gain
high sensitivity
Medium sensitivity
Low sensitivity
Nominal output level
(ref 5.2mV, MM, Low)
Inputs
outputs
Power consumption
“The Quad II Classic
uses the finest quality
components, each
hard wired onto a
robust chassis with
solder tags..”
specifications
40W RMS
0.3% @ 40W
0.03% @ 1W
Better than -80dB
10hz–30khz(+0dB/-0.5dB)
20 @ 700hz
180W maximum
4 ohm and 8 ohm
2 x 6Sh7 Input
2 x KT88 output
1 x 5U4G Rectifier
1V
RMS
15W RMS
0.3% @ 12W
Better than -90dB
10hz–20khz(+0.2dB)
11.75 @ 700hz
90Va maximum
8 ohm
2 x EF86 input
2 x KT66 output
1 x GZ34 Rectifier
1.4V RMS
Model
II-forty
II-classic*
Power output
Thd @ 700hz
Residual hum & noise
Frequency Response
damping Factor
Power Consumption
Loudspeaker Taps
Valves
Sensitivity
*The Quad II Classic power amplifiers are supplied in matched pairs.
80W RMS
0.3% @ 40W
0.5% @ 80W
Better than -94dB
10hz–30khz(+0dB/-0.5dB)
16 @ 1khz
180W maximum
4 ohm and 8 ohm
2 x 6Sh7 input
4 x KT88 output
1 x 5U4G Rectifier
1V RMS
II-eighty
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