Hartke HA5500 XLR Buzz

Discussion in 'Amps and Cabs [BG]' started by littlebooner, Jul 11, 2013.

  1. A few months ago I picked up my new Hartke HA5500 and 2 Hydrive 1x12 cabs. I've been really happy with the rig for tone. However, I'm getting buzzes and hums when using the XLR out. In a live setting, I get a big crack when I turn the amp off and then a constant buzz in the PA when it is off. When recording, there's an underlying hum on the signal even when my bass level is 0 and my amp is powerd on or off. The only thing that stops it in either case is removing the power chord from the amp.

    Here's some trouble shooting I've tried with no success:
    -Ground lift switch
    -Unplugged my bass while amp is on to make sure it's not the instrument
    -A different XLR cable (different ones were used between live and recording)
    -Making sure the amp is on a separate breaker from stage lights/computers and other possible electronic interference.

    Any other thoughts for troubleshooting?
  2. Tried a different power cord?
  3. I've encountered this when running sound--lots of amp XLR outputs buzz and make bad sounds, like the circuit is an afterthought instead of an intelligent design.

    (FYI, you'll always get a loud crack or pop through the PA if you turn a connected amp on or off, so never do this unless your channel is muted at the mixer, or be prepared to pay for new speakers and get called bad names. I've also seen a lot of amps buzz the PA when off, but not when on.)

    One thing to try is a modified XLR cable: Open up the female connector (that plugs into your amp) and cut a gap in the wire to pin #1, which is the ground wire.
    This eliminates any possibility of ground-loop hum.
    (I carry a foot-long XLR cable with this mod just in case).

    If you still have hum, there's something wrong with your amp and it needs service.