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The
Control unit is at the heart
of the Quad 22 system, as it performs many
functions...
- accepts stereo inputs from sources - tuner, tape,
disc etc...
- switches between sources and stereo/mono modes.
- distributes the necessary voltages to power valves
in other units such as the FM tuner.
- controls the power-on, volume, balance EQ, and
filter functions.
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| The design
of the unit won many awards,
and broke many conventions at the time of manufacture. It still remains
striking, but
at the same time, is tremendously functional. |
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The filter control allows
subtle variation of the unit's frequency
response - to remove high
frequency hiss, crackle and distortion. It should nominally
be set to the level/7K position, but would
be set to 5K for older recordings, and 10K
for high quality transmissions. When the left-hand control is set to cancel,
both the filter and bass
& treble controls are disabled. |
| This is the famous Quad logo light
which illuminates when the unit is switched
on. Predictably, Quad
didn't go for the standard red neon indicator,
but instead employed their own design iconography.
I think it adds to the glow-in-the-dark
feel of vintage Quad equipment, and Quad
used the same type of indicator for many subsequent
models... |
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The push-button section
of the control unit tells us much about the
time when the Quad 22
was produced. There are inputs for microphones,
two radios and two disc
players - this is indicative of the
fact that home hifi was in its formative
years, and no one was quite sure where it
was going. Also, the change-over from mono
to stereo was taking place, so here we find
buttons to choose from stereo,
mono right, or mono
pair options. Aswell as selecting the
input source, the push-buttons
control where the high and low
tension voltages are sent (eg to the FM
unit). |
| The elegant
volume control also acts as the main power on
switch, and below it is the balance control.
Swinging it from left to right
changes the loud speaker balance accordingly. |
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These two leads emerge from
the back of the control
unit (see picture below) and connect to the
two Quad II power amps. They carry mains
voltage and output signals down to
the Quad II's, and carry
low and high tension supplies back
up to the control for
distribution. |
| The rear of the control
unit accepts all the signal inputs via
a choice of phono (interestingly slightly
smaller than today's) or adaptor sockets.
The colour coded connections supply the low
and high tension valve supply voltages. The
mains supply and Quad
II connection leads (described above) also connect on the rear
panel. |
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control...