How do I properly manage power amp gain?

Discussion in 'Amps and Cabs [BG]' started by Arranger, Mar 1, 2004.

  1. Arranger


    Mar 9, 2003
    This may be the simplest question of all...

    I have a Samson Servo 550 (275w/channel@8ohms, 550w bridged@4ohms) stereo power amp that I'd like to run for PA or bass rig setups. Do I just leave the gain all the way up on both channels and control my final output at the board when used for a PA system or with a bass preamp when used for my bass rig?

    ...or should I really back off the power amp gain by some reasonable level to keep it from clipping? I've been in the habit of running it for a stereo keyboard application with the gain control knobs set around 75%.

    For a bass rig, I'm now considering taking the XLR out of my Hartke Kickback12 and going into a mixer, then through the power amp into my Ampeg Cabs. What type of sound quality should I expect? This way I still get the Kickback for a stage monitor, too.

    Thanks for your experienced replies.
  2. TimmyP


    Nov 4, 2003
    Indianapolis, IN
    The amp's sensitivity is rated as +4dB input (1.23v) for full power. Running the level controls at full should be fine in most situations.

    Backing off the gain controls will not keep the amp from clipping. It will just take more output from your bass preamp or mixer to clip it. Since most preamps and mixers are capable of putting out at least +12 dB (many can do more than +20), unless you turn the input controls down ridiculously far, the amp will always clip first.
  3. Arranger


    Mar 9, 2003
    Thank you very much, TimmyP. That makes sense.

    By the way, I checked out your links and have learned much more. I appreciate you sharing your expertise.

    Enjoy the day!