Linn 2250, Owner'S Manual

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Signal Sensing
The signal sensor in the Linn 2250 power amplifier waits about one second before
powering-up the amplifier to be certain the input signal is real, not just noise.
The detection threshold is a good compromise between sensitivity to low-level
signals and immunity to noise. However, residual hiss level from phono preamplifiers
at moderate volume settings can be enough to trigger the sensor. Mute the
preamplifier or turn the volume down after use to prevent this happening.
If there is audible hum from the loudspeakers then you may have enough noise
present to trigger the signal sensor. Always try to eliminate any source of hum as this
is essential for a system to sound its best.
Ten minutes after an audio input signal ceases, the unit reverts to a low-power
standby mode.
Heat
The Linn 2250 power amplifier is very powerful and hence must dissipate a lot of
heat. This is normally done via the internal heat sink and vents in the outer casing.
However, if the amplifier is being worked enthusiastically or has restricted ventilation,
the unit’s two internal fans will operate and will remain running until the internal
temperature had dropped to a pre-set level.
Operation
The blue light on the front panel will be dim when power is first applied, and remains
dimmed when the unit is in standby mode. When a signal is detected the light
brightens as the amplifier is enabled. If the amplifier needs to protect itself (for
example, if the internal temperature gets too high) it will shut down for a few
seconds and the light will dim. There is no half-way current limiting: the unit can
either do what is required of it or will shut down. The amplifier will revert to standby
mode ten minutes after the input signal ceases.
To operate the Linn 2250 power amplifier, select a source on your preamp, wait a
couple of seconds for the unit to power up, then sit back and enjoy it.
English