Shit - this scared me - any advice?

  • So I have used the Kemper (Rack, no power amp) for 3 weeks and I am fully impressed.
    Today I got scared however.
    At band rehearsal the Kemper started to act strangely.
    After, say 45 minutes, I am playing a clean sound. and slowly the sound gets more and more distorted. After 2-3 minutes it sounds like full distortion, lost of noise and stuff.
    It doesn't matter if I change to different rigs. Awful.
    So I shut down the Kemper and restart. Everything is fine and after 2-3- minutes it starts again.
    I change cable, guitar, where I get the power from and so on but this is really happening inside the Kemper.
    Shut it down a few times, keeps repeating.
    So I switch back to my normal amp and after an hour I try agin with the Kemper. No issue, play happy for 1,5 hour.


    This makes me very worried. If this would happen during a gig I would be screwed.
    Has anyone had a similar experience before? Or any advice on what to do? Everything looks fine again but I am scared that I do not know what happened here... ?(
    Could there be interference with my Sennheiser 300 IEM G3 In Ear unit that I have in the same rack?

  • I've never had anything like that happen, and I don't think interference could play a part either. Double, no triple check your firmware version, buy all the Michael Britt profiles, then profit! I gig with mine regularly, ASA well as record & practice with it and it's rock solid.

  • I am now wondering if it may have to do with "bad quality" power at the location where I was.


    In this case I would recommend a power conditioner. I personaly use a small UPS system for aprox. 60,- Eur.
    Anyway what you decribed I never heard about.
    Contact support

  • Had something similar in a way. I had just gotten the KPA and set it up, to play through my power amp and cabs. In my case the noise was there a litt,e but the sound just dropped, then came back or gone, back, gone, back. Until total silence. Until I turned the master, than it sometimes would come back.


    Eventually the reason was analog, a bad cable somewhere in my chain. Maybe worth the elimate.

  • Yes, I will do that in case it happens again. Unfortunately can't replicate it today...


    Something similar happened to me two years ago. I could play without problems for a hour or so and then the noise and distortion appeared. The problem was always in one of the main outputs, but only one of them so sometimes I couldn't replicate the problem without I was using the other one...


    I had to send it back to Kemper to replace part of the hardware.

  • Not sure what your cause is but i had a similar issues several times that only ever occurred in the practice space and managed to resolve it.


    The symptoms were:
    Every few hours a Rig would get noisy with a static digital sounding crackle/hum that would grow in volume over 15 seconds or so until it was as loud a s the profile volume. Turning guitar volume down, switching wireless body pack off, switching to silent tuner mode (via kpa remote) all silenced the guitar signal, but not the growing crackle/hum (which made my clean patches appear distorted when playing). Output signal chain was simply: KPA Main out (mono)> xlr> to mixing desk>desk main outs to PA


    The cause:
    After going through everything I could think of (ground loops, wireless interference, KPA memory refresh, FW downgrade/upgrade, different power circuits etc, etc) the issue was solved by simply replacing the xlr I was using to go from the KPA main out to the mixing desk. I still don't understand how a bad xlr would cause the symptoms, but swapping it out fixed it. ?(
    It only occurred in the jam room as we have permanent cabling that is always strung out at the jam room and a second complete set that is used for gigs. Safe to say that particular XLR got cut into tiny pieces for being a jerk and promptly thrown in the trash.


    Possibly not the cause of your noise, but the description of your problem sounds damn close to what I was fighting. Hope it helps!


  • Hi Greenly,


    what you described was exactly what I experienced. You described it better than I did at the start of this item. So you you so much for taking the effort to help me. I will change the XLR cables in my rack from the KPA to higher quality and am hopeful this will do the trick.


    Note: I hope it is not because we both play a Nick Huber, love your guitar :) (I actually changed the guitar yesterday to see if it mattered...)

  • Every few hours a Rig would get noisy with a static digital sounding crackle/hum that would grow in volume over 15 seconds or so until it was as loud a s the profile volume. Turning guitar volume down, switching wireless body pack off, switching to silent tuner mode (via kpa remote) all silenced the guitar signal, but not the growing crackle/hum (which made my clean patches appear distorted when playing). Output signal chain was simply: KPA Main out (mono)> xlr> to mixing desk>desk main outs to PA


    This is exactly what happened to me. But unfortunately, it was not the cable but the internal electronics.


    I hope EdRaket problem is only the cable! Good luck.

  • I have exactly the same symptoms in one of my home-stereo monitors, an Alesis 720DSP (my old studio set). The noise (gritty, crackling white noise) builds slowly for around 15 seconds, and sometimes frustratingly takes a minute or two, then after reaching its peak, stops altogether. Sometimes when the stereo's set quite loud I think it's pelting down with rain before I realise it's the speaker.


    I've had this issue for at least 5 years, assuming all along it was a capacitance build-up in the monitor, but after reading this thread, I'm keen to swap the XLRs that feed the pair. Nothing to lose, right? It's the only thing I haven't tried as the plugs and cables are of the "highest" quality and were bought new for the setup. Still, you never know, so thank you Ed for sharing your issue.

  • :( Latest status update. Unfortunately the problem is back. I am now 100% sure it is the Kemper itself that causes the problem. Guitar in at the from input, headphone out at the front and I still hear the all distorted sound. There are no XLR cables or other components involved.
    I am now arguing with the shop where I bought the Kemper that I want to replace it. The are reluctant to send me a replacement, which I think is ridiculous as I bought it on Februari 25th. I did make a small movie of the problem occurring and will try to post that later today to this mail. To be continued.
    Oh yes, I have also logged a ticket with Kemper a week ago. I send them the movie showing the problem. My first priority is to get a replacement before the gig I have coming Saturday... ;(

    Edited once, last by EdRaket ().