Руководство Пользователя для Lab.gruppen fp 1150q

•  Make sure that the power switch is set to “off” before connecting any input or output or 

operating the switches on rear panel. See pages 

 about installation. 

 
•  Make sure that the AC mains voltage is correct and the same as the one printed on the rear 

panel of the amplifier. See pages 

, about operating voltage and power consumption. 

 

•  Make sure that the switches on the rear panel for operation modes and clip-limiter switch are in 

 about operation modes and page 

 about clip limiters. 

 

•  It is always a good idea to turn down the gain controls during power-up, to prevent speaker 

damage in case a high signal is present at the input. 

When you power up the amplifier it takes a couple of seconds to check its circuits. This is known as the 
"soft-start" or "slow-start" sequence. The fans then blow at high speed before going into "idle" and the 
four bottom green LED’s illuminate to show the amplifier is operational. 

The four input level attenuators on the front panel adjust the signal level for their respective amplifier 
channel in all modes. They are calibrated in dB to help setting up active loudspeaker systems or cutting 
down unwanted noise from the input signal.  
In bridged mode, both controls must be in the same position, so that the speaker load will be shared 
equally between the channels. 

 

The yellow LEDs at the top indicate if 
any protection circuits are activated. 
These are described on page 

. 

 
The Clip/limit indicator tells when the 
amplifier output is clipping or limiting. It 
has two different indication statuses: 
•  If the clip limiter is engaged it has a 

short time constant and it illuminates 
briefly. 

•  If the clip limiter is not engaged it 

has an increased time constant and it 
illuminates for a longer period. 

 
The ”-40 dB” LED’s illuminate if the output signal is greater than -40dB (with 0dB as reference to full 
output power). These LED’s also act as signal present indicators.  
 
The four bottom green ”ON” LED’s indicate that the output circuits are receiving the correct rail 
voltage.