Hissing Output that goes away after ~5 minutes

  • Guys,

    Is there a warm up time associated with the Kemper? I bought my Kemper new from Sweetwater and noticed when I plugged into my Alto speakers that there was a rather loud high frequency hiss that gradually went away after 5 minutes or so. When it goes away it almost sounds like the the hiss is stuttering. I unfortunately thought that this was the Alto speaker doing this cause I didn't get that same sound on the headphone jack, however, I noticed it when going into other speakers and when plugging the main outs into my DAW interface. So in other words, its the main outs doing this. Anyone else experienced this? I'm unfortunately past my 30 day return, but maybe I could talk with them at Sweetwater if this is a faulty system. After the hiss goes away I do get the random buzz sound that go buzz...click on the output but I haven't fully determined if that's the Kemper or something else. Thanks all.

  • There is no warm up time.


    The fact that the hissing stutters sound like the main noise gate is set just on the threshold of being too low or too high and is only catching some of the high gain profile’s noise floor.

    This happens on any profile, clean or dirty. It's really loud relatively speaking for 5 minutes and then goes away. The fact that it goes away makes me think it is something different than the noise gate.

  • OK so that would seem to suggest the noise gate isn’t the cause. If it isn’t doing it on the headphones it is unlikely to be software related either. Therefore, the most likely culprit is hardware fault (either Kemper or something else in the chain).


    Is the buzz similar to a ground loop?


    Do you have a computer connected by USB and/or SPDIF?


    Have you tried plugging the monitor out into the Alto with monitor out set to Master Mono? Does it do the same?

  • I will try those suggestions to see if there's any changes and get back to you. Thanks for your help.

  • Are you still experiencing this issue? I've been getting this too ever since I bought the kemper and never figured out what the problem was. Happens through headphones too for me, but doesn't seem like it's as loud as what you were getting

  • I had the exact same thing for a few years after I got my Kemper (2014)


    It eventually went away on its own, or possibly with an update. I have no idea what was going on with that. I may have even started a thread about it. Will check.

  • Are you still experiencing this issue? I've been getting this too ever since I bought the kemper and never figured out what the problem was. Happens through headphones too for me, but doesn't seem like it's as loud as what you were getting

    I don't seem to get it through my headphones. I haven't been playing through speakers much lately so I assume it still happens but will check.