4.3.a) Signal presence indicators "SIGNAL" (5)
They show the presence of a signal at the amplifier inputs. They shine when the input
level is greater than -40dBV.
4.3.b) Protection indicators "PROTECT" (3)
Besides lighting up during stand-by mode (when switching on the unit), these
indicators will light up for following reasons:
1- Because there is a short-circuit at the amplifier output. In case of a permanent
short-circuit, the protections will disconnect the amplifier in less than 70µs (Models 1100 and
2100); models 4100 and 6100 continuously protect and disconnect in 15s. The protections
also become active when there exists an excessive high frequency clipping, thus protecting the
tweeters
2- If the amplifier is supplying DC signal or very low frequencies that could damage
the loudspeaker. The protections detect frequencies under 4Hz. A CROW BAR system is used
to separate the loudspeakers from the output terminals.
If the indicators are permanently lit, this is a symptom of malfunction and the cause
should be investigated.
The Autoreset system will cyclically restart the amplifier after about 15-18 seconds.
If the problem still persists, please consult our Technical Services.
4.3.c) Clipping indicators "CLIP" (2)
They will shine when the output signal is 0.3dB under the true clipping. This system
takes into account the possible changes of the mains supply and always gives a true measure
independently of the mains voltage. It is usual that the CLIP indicators shine following the bass
frequencies when the amplifier operates at high power levels. Take care that the CLIP indicators
are not permanently lit.
4.3.d) "MONO BRIDGED" indicator (6)
It shines when the back panel "STEREO BRIDGE" switch is placed on the BRIDGE
position.
4.3.e) Thermal protection indicator "THERMAL" (4)
It shines when the cooling tunnel temperature reaches 90ºC. The amplifier will
automatically restart when the temperature lessens to 80ºC.
4.4. Operation at 2Ω
Operation at 2Ω considerably reduces the sound quality and the system efficiency; e.g.,
the loss on the loudspeaker cable reduces the Damping Factor by a 76% because of operating at
2Ω instead of 8Ω.
All manuals and user guides at all-guides.com
9