low amp signal ?

[killa]

So I am rumming a QSC 850 with a psa 1.1 preamp. The issue is a low signal unless the pre and volume on amp are cranked pretty high. The yellow signal light barely lights up unless I crank the volume on the amp up. Is the signal light suppose to light up more when I adjust the volume on the amp up? I think it should light up more with the signal incoming to the amp and only the signal going to amp but it also lights up more when the actual amp gets turned up.
Also until I get the signal light to stay lit most of the time things just don't sound good (no attack on bass, guitar sounds weak) Issue is once the signal light really starts to light up and things start to sound good it is pretty loud for practicing at home.

[Paul O]

Re: low amp signal ?

So I am rumming a QSC 850 with a psa 1.1 preamp. The issue is a low signal unless the pre and volume on amp are cranked pretty high.

You need to have balanced(3 conductor) XLR or TRS interconnects between the preamp and amp and make sure the preamp is switched to produce 0db output levels not -10db. Then with the poweramp attenuators wide open it should reach clipping levels at about 50% of the preamp volume control.

[kblackmore]

Re: low amp signal ?

The "volume controls" on the amp are actually gain controls. They are used to match the gain of the amplifier to additional amplifiers or lessen the gain of the amplifier in case you have a mixer that has a hot output to keep the system manageable. Most DJ's and musicians turn the gains wide open and leave them there. You won't cause any damage to the amp by running it that way. As Paul suggested, make sure you have the proper connectors.
To properly set the gain structure on a system with a single amplifier, turn the preamp\mixer to 50% and adjust the amplifier gains up to the desired volume. This gives you plenty of room to adjust the volume up or down on the mixer\preamp while ensuring the system has the headroom for any peaks that might arise.