Further Information - Quad Electroacoustics QUAD II Classic Integrated Owner's Manual

FURTHER INFORMATION
Running In New Equipment
Running in k very important. Valve components vrark at high voltages and
temperatures and when new th^ should spend an eittended period at those
temperatures to bed in. We recommend you run the amplifier in for at least four and
preferably twelve hoius before you first use it. If you run in your equipment for this
extended period, make doubly sure dtat all the safety conditions covered in this manual
are fully met. Supervise the equipment for the first hour or so and if you have to leave
the unit unattended thereafter, look in occasionally to make sure all is well.
Warming Up Before Use
Allow at least fifteen minutes for the amplifier to 'warm up' before use. If you play
loud music while the system is cold the output valves will not be fully operational and
the amplifier will be starved of voltage and current. The resulting distortion is
unpleasant and potentially damaging to the amplifier's valves and your loudspeakers.
Intensive use of the equipment before it has warmed up will shonen vaKc life.
Valve Lifetimes
Valves contain a heating element. This heats up the valve's cathode, which is coated to
give off a steady stream of elections. After a few years this coating will begin to wear
out and performance will gradually deteriorate, the Kr66 output valves are likely to
deteriorate first but the driver valves will also eventually wear out.
As the valves start to wear out the sound will become less well defined and a lack of
dynamics and power will become evident. Replacing the valves with a new set will
fully restore the audio performance of the amplifier. When replacing valves it is
essential to use the highest quality available. Poor quality valves will adversely affect
the sound quality and may in extreme cases damage the amplifier. When replacing the
output valves, use matched sets for best results.
Do not leave the amplifier permanently switched on or you will seriously shorten
the lifispan of your valves!
Output Transformer
After installing oi changii^ the wiring to your speakers, keep the volume control at
zero, let the amplifier warm up and turn up the main volume gradually. If you don't
hear sound, switch off immediately and investigate.
The output transformer is designed to match the fai^ voltage, low current conditions
in which the output valves operate to the low voltage high current requiremencs of a
loudspeaker. Although robust, an output transformer can be damaged and, in extreme
cases wrecked, by careless use. If you play a valve amplifier into a short cirruit, the
output transformer will soak up a lot of energy before failing, but if the short persists
the transformer could be damped. Operating a valve amplifier at high output levels
with TU! loudspeaker connected can also damage an output transformer.
Overall Volume Levels
Output levels from different source components in a high fidelity system can vary
widely. A CD player can produce levels significandy higher (>18 dB ) than an FM
tuner. It foUows that the position of the volume control is not a guide as to 'how loud'
the equipment will go. Though the overload characteristics of the amplifier are such
that you can play your music at surprisingly high levels, if the sound is distorted, you
are overloading your equipment whatever the position of the volume control.
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