Audio output pops during startup & shutdown

  • hi folks, kemper stage..

    audio outputs make a very nasty pop both during startup and shutdown. And i mean nasty.


    before folks say "power down the PA first" etc - that's not always possible. I'm doing theatre shows and i'm buried in a pit with no communication to the FOH engineer. The PA is well and truely powered up before I arrive for the night, and various foldback sends around the venue are live, including the rest of the musicians headphone mixers. So me arriving and powering on my kemper has the real possibility of hurting some ears.


    In addition, if there's an issue during the middle of the show (accidental loss of power to the kemper, or it has a hissy and needs to be rebooted) - the pops will go through to the massive FOH system to the audience and scare the crap out of the engineer.


    We know it's possible to have muted outputs during start/shutdown, plenty of other devices do. My helix doesn't do this.. it's totally 100% silent during bootup and i can confidentally not only reboot it mid show without anyone ever knowing - but even un-plug the XLR outputs and plug back in with zero pops through the PA.


    hoping there's a way of achieving this..

  • Do you use a power sequencer for your live rig?


    I have several monitors that would pop on power-on in my studio so I just added a sequencer and --- problem solved.

    Larry Mar @ Lonegun Studios. Neither one famous yet.

  • Until Kemper comes up with a silent shutdown/startup, consider getting cables with silent switches in them. That way, you can cut off the signal from the Kemper before you start or shut down the unit.

  • I totally agree a mute for silent power on/off would be a great function.


    I understand the benefits that you experience with your Helix and agree the KPA should be able to do the same.


    However, the part about plugging/unplugging cables shouldn’t be linked to a mute function. The cable connection happens after the mute so surely you should still be able to unplug the cables from the KPA without any pop in the same way as you do with the Helix.

  • Do you use a power sequencer for your live rig?


    I have several monitors that would pop on power-on in my studio so I just added a sequencer and --- problem solved.

    Sorry, that doesn't help in the slightest. I'm not talking about a small setup in one room. I'm talking about a theatre with line array PA, 70+ channels of audio and foldback sends around the venue for days. The power on sequence for the audio team each night is substantial as equipment is spread throughout the venue.. and this is done well ahead of me arriving. I'm buried down in an orchestra pit miles away from the PA system as a whole. (as in for me to walk from my rig to FOH would literally be a 5 minute walk by the time i've traversed 4 flights of stairs!!)

    A power sequencer also doesn't solve the issue of pops occuring as a result of needing to reboot the Kemper mid-show if there's a glitch.

  • I totally agree a mute for silent power on/off would be a great function.


    I understand the benefits that you experience with your Helix and agree the KPA should be able to do the same.


    However, the part about plugging/unplugging cables shouldn’t be linked to a mute function. The cable connection happens after the mute so surely you should still be able to unplug the cables from the KPA without any pop in the same way as you do with the Helix.


    Right you are. Kemper does seem to be silent with respect to plugging XLR's in and out. :)

  • Until Kemper comes up with a silent shutdown/startup, consider getting cables with silent switches in them. That way, you can cut off the signal from the Kemper before you start or shut down the unit.

    Interesting idea.

    Unfortunately that would add a point of failure that i'm not sure the audio guys would want... as i'd basically be plugging an adaptor (or short patch lead) with embedded switches into the kemper that then in turn plugging into the XLR cables that run to me from the digital multicores. We (for obvious reasons) try and avoid joining cables in this way. I'll do some research but not totally keen on the idea.

  • ofcourse, based on the discovery that the XLR's don't seem to make any pops upon plugging in/out - i "could" unplug the XLR cables each night and plug them back in after booting.

    However, i guess my issue is I shouldn't HAVE to do this. And, in an environment where my rig is set up and cables are all taped down, and it's basically a permanent installation for a month or so - we actively avoid plugging and unplugging things to reduce potential for faults.