ekco EV55SE, User Manual, Page: 9 / 12

FURTHER INFORMATION
Running In New Equipment
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.
We recommend you run the amplifier in for at least four and preferably twelve hours
before you first use it. If you 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 unit unattended thereafter,
look in occasionally to make sure all is well.
Warming Up Before Use
Allow at least fifteen minutes for the amplifiers 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 amplifiers' valves and your loudspeakers. Intensive use
of the equipment before it has warmed up will shorten valve 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 electrons. After a few years this coating will begin to wear out
and performance will gradually deteriorate. the KT66 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 amplifiers permanently switched on or you will seriously shorten the
lifespan of your valves!
Output Transformer
After installing or changing 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 high voltage, low current conditions in
which the output valves operate to the low voltage high current requirements 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 circuit, the
output transformer will soak up a lot of energy before failing, but if the short persists the
transformer could be damaged.
Operating a valve amplifier at high output levels with no loudspeaker connected can
also damage an output transformer.
Never operate the amplifier with the Speaker A/B switch set to a position where
no speakers are connected.
Overall Volume Levels
Output levels from different source components in a high fidelity system can vary
widely. A CD player can produce levels significantly higher (>18 dB ) than an FM tuner. It
follows 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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