10
6.3. Indicators
GPA2-400ES
amplifiers include a simple yet effective indication system.
CLIP/STBY indicators show the absence of loudspeaker output signal. These indicators
may light up for following reasons:
1.
During start-up, until the STANDBY time has passed. This time period is needed
for the internal operating voltages to settle.
2.
A short circuit is detected at the loudspeaker terminals (PROTECT function).
3.
The amplifier is outputting direct current or very low frequency signals that could
damage the loudspeaker.
In any case, should these indicators light permanently, this is a sign of malfunction and
the causes should be investigated.
The CLIP/STBY indicators light up just before the actual clipping threshold at the
loudspeaker output is reached. The clip detection circuit considers supply voltage
oscillations, so that a dependable clip reading is achieved, even when operating with
unstable mains voltage. It is usual that the CLIP/STBY indicators shine following the
bass frequencies when the amplifier operates at high power levels, as these frequencies
carry the main energy. Take care that the CLIP/STBY indicators are not permanently lit.
SP Signal Presence indicators indicate the presence of a valid signal at the amplifier
inputs.
The TH (THERMAL) indicator lights when the unit has entered the protection mode due
to excessive temperature; normal operation is recovered when the amplifier internal
temperature comes back down to regular operating levels.
7.
CLEANING
The front panel should not be cleaned with dissolvent or abrasive substances because
silk-printing could be damaged. To clean it, use a soft cloth slightly wet with water and
neutral liquid soap; dry it with a clean cloth. Be careful that water never gets into the
amplifier through the holes of the front panel.
