If this is your first valve amplifier please familiarise yourself with some important issues surrounding the safe use of the QUAD II Classic.
Loudspeaker Connections
Valves Get Hot
Valve power amplifiers generate a lot of heat even with no input so it is vital to ensure adequate ventilation for your power amplifiers. QUAD II Classic power amplifiers should not be placed on a rack; each unit should be on a stable solid
Although the protective cage over the QUAD II Classic gets hot it is very unlikely to cause a burn. For absolute safety the units should be placed out of the reach of children and pets and away from
Valve Amplifiers Work at High Voltages
Valves require a high voltage to function. Do not open any of the cases. Also ensure that nothing is poked, dropped or poured into an amplifier's case.
!
To
Speaker
Strip any outer sleeve from the cable to a depth of around 40 mm (1.5”). Strip the top 7mm of sleeving to expose the bare wire.
!If you are using stranded cable, lightly twist the strands to gather any loose ends.
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!Partially unscrew the knurled portion of the terminal to expose the cross hole at the terminal base.
!Push the bare end of the cable into the hole. Ensure that the polarity is correct and there are no loose strands which could touch adjacent terminals.
!Tighten securely.
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!Connect the Red (Positive) terminal of the loudspeaker to the +ve terminal of the amplifier. Connect the Black (Negative) terminal of the loudspeaker to the
!Ensure that the Left and Right loudspeakers are connected to the Left and Right amplifiers
respectively.
!
The environment should be dry and free from litter. Do not place magnetically or thermally sensitive objects (i.e. credit cards or optical discs) close to these QUAD units.
Valves are Microphonic
Because valves are constructed from fine wires and tiny metal parts they can pick up external vibrations. If you place the power amplifiers too close to the speakers the direct loud sound may vibrate the valves. 1 metre (3ft) to the side of each speaker should be considered a sensible minimum.
Interconnects and Cables
The signal input to the amplifier is via an RCA phono connector. As valve equipment works at high impedances, the phono interconnect from the
Choose good quality loudspeaker cable designed for the purpose rather than general purpose ‘zip’ or ‘bell’ wire. It should be of adequate gauge to maximise bass performance.
CONNECTIONS
Note: Before connecting your amplifiers all components in the system must be unplugged at the mains and the master system volume control set at zero.
Final System Connections
Ensure that the mains switches on the power amplifiers are switched OFF and that the
OPERATION: Read this section to maximise the performance and lifespan of your Quad II Classic.
Switch on the power at the wall. Switch on the power amplifiers and other source units.
When the amplifiers have warmed up, the system may be safely used (see below). Warming up (or running in) should always be done with the volume control at zero.
Always remember to switch the power amplifiers off when they are not in use
Running In New Equipment
Most high fidelity equipment works better after it has been run in. With valve amplifiers running in is very important. Valve components work at high voltages and temperatures and when new they should spend an extended period at those temperatures to bed in. This is especially the case with the output valves and the output transformer.
We recommend a running in period of at least four and preferably twelve hours before you first use the equipment. If you decide to run in your equipment for this extended period, make doubly sure that 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 equipment unattended thereafter, have someone look in every so often to make sure all is well.
Input Connections
230V~50Hz T1AL FUSE |
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115V ~60Hz T2AL FUSE |
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+VE | INPUT | |
Switched Mains | Loudspeaker | RCA Phono | |
Socket with | |||
Terminals | Input Socket | ||
Integral Fuse | |||
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The Quad II Classic must be connected to a pre- amplifier line output, or to the line output of a source component which has a variable volume control. You must not connect the amplifiers to any source which has only a fixed output.
Decide which of the two power amplifiers is to be the left channel and which the right channel and place the units in their intended locations.
Using an appropriate screened RCA phono cable, connect the input socket of each QUAD II Classic amplifier to the requisite line output socket of your
When running signal cables, keep them away from sources of interference. Do not run signal cables parallel to cables carrying mains or digital traffic.
Warming Up Before Use
Allow at least fifteen minutes for the amplifiers to 'warm up' before use.
Valve amplifiers need time to reach their correct operating temperature. 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 both voltage and current. The resulting distortion is unpleasant to listen to and potentially damaging to the amplifiers' valves and your loudspeakers.
Valve Lifetimes
The valves in the Quad II Classic will perform to specification for years if used properly.
Valves contain a heating element. This heats up the valve's cathode, which is coated to give off a steady stream of electrons. After a few years this coating will begin to wear out and performance will start to deteriorate. In the QUAD II Classic amplifier the KT66 output valves are likely to deteriorate first but the EF86 driver valves will also eventually wear out.
Do not leave the amplifiers permanently switched on or you will seriously shorten the lifespan of your valves. Always switch the amplifiers off when not in use.
Intensive use of the equipment before it has warmed up will also shorten valve life.
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