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Hum in channel 1

Discussion in 'Live Sound [BG]' started by JimiLL, Oct 9, 2022.

  1. Oct 9, 2022 #1
    JimiLL

    JimiLL

    Jan 26, 2009
    Hunt. Co., New Jersey
    I’ve been reconfiguring the rack for my bass rig recently, and noticed I’m getting a hum on channel one but not channel two.

    The amp is a carvin dcm 1500. Could sone Schmitz somewhere be the issue?
     
  2. Oct 9, 2022 #2
    Mike Caldwell

    Mike Caldwell

    Feb 27, 2006
    Mid West Ohio
    Need some more info on what else is in the rack, maybe a picture of the back of the rack showing the connections.
     
  3. Oct 10, 2022 #3
    JimiLL

    JimiLL

    Jan 26, 2009
    Hunt. Co., New Jersey
    There’s a ampeg svp going into Sansamp rbi then into the amp. Everything remains the same except the channel on the amp I’m using
     
  4. Oct 10, 2022 #4
    Mike Caldwell

    Mike Caldwell

    Feb 27, 2006
    Mid West Ohio
    How are you operating the amp, bridged, stereo or dual mono?

    Why two preamps in series?
     
    Zooberwerx likes this.
  5. Oct 10, 2022 #5
    Zooberwerx

    Zooberwerx Gold Supporting Member

    Dec 21, 2002
    Virginia Beach, VA
    Definitely need more info on the configuration. I quickly scanned both manuals...appears the FX loop on the Ampeg may be the best way to piggyback the pre's. It will require a footswitch and some judicious gain adjustments. The DCM 1500 has all the goodies (parallel inputs, bridge, etc.).

    Riis
     
  6. Oct 14, 2022 #6
    JimiLL

    JimiLL

    Jan 26, 2009
    Hunt. Co., New Jersey
    I’m running the svp into the Sansamp then into the power amp because that’s the only way it wants to be run. Tried sa into fox loop of the ampeg it was a bad match. Tried sa into front of ampeg it was a noisy mess as well.

    I use one channel of the amp in stereo.
     
    Zooberwerx likes this.
  7. Oct 14, 2022 #7
    Zooberwerx

    Zooberwerx Gold Supporting Member

    Dec 21, 2002
    Virginia Beach, VA
    Got it. A SansAmp pedal would work on the front end of the Ampeg...I woulda thunk the rackmount would do the same with some judicious gain shuffling. You're running 1/4" >< 1/4" between the SA and Carvin (channel 1), correct? With the "Parallel Inputs" activated, you should be able to cleanly run an enclosure off each side.

    Riis
     
  8. Oct 14, 2022 #8
    Mike Caldwell

    Mike Caldwell

    Feb 27, 2006
    Mid West Ohio
    Try using an XLR cable between the pre amp and the power amp.
    Are you using an unbalance tip sleeve 1/4 inch cable now.
     
  9. Oct 16, 2022 #9
    crazyBassClown

    crazyBassClown

    Sep 25, 2007
    sydney, australia
    Do you get the hum with nothing plugged in?
    Using something else into the amps?
    If you can identify if the hum is in the amp or the preamps it will help solve the issue.
    If it is only in channel 1 there is probably a problem in channel 1 that needs to be fixed by a tech.