Help: Kemper makes crackling noises

  • Hi there,


    Since yesterday, I have a very annoying crackling.


    I made a quick recording.


    My usual setup Guitar -> front input -> Headphone out. I also hook up the output of my mac via the Aux In. This setup has been working without any flaws for more than 2 months.


    I'm on today's latest OS release, but the noises started before I updated.


    What I tried:

    • Using Alternative Input as well as monitor out and main out
    • Different guitar and different cable
    • Not using Aux In and USB
    • Hooked up the Kemper to different power sockets
    • Tried the ground lift switches
    • System reset as well as Flash Init.

    Nothing worked, except for the Flash Init, but the noises came back when I restarted the unit. I tried another Flash Init, but that had no effect.


    I can't use the unit like that... I bought it used via Paypal and can still send it back to the previous owner and get a full refund.


    I have the feeling it's a DSP issue, but I might be wrong.


    I will also open a support ticket, but I was hoping that you might have had similar issues that you were able to solve.


    Thanks for your input in these desperate times ;(

  • Sorry I can't hear the crackling on my CrapMac™ system, Yannick; probably too much ambient noise here, so I can't hear any clues as to what might be causing it.


    Something to consider 'though:

    The noise only began yesterday, and it's possible it's line contamination caused by someone else in the neighbourhood or immediate vicinity. If it's not practical to take your unit somewhere far from where you are and plug in there to test, maybe you could pop over to a nearby-neighbour's house in the meantime.


    Failing these options, it might be worth waiting a few days to see if it clears up.


    Sorry, mate; that's all I've got. I feel your pain! ;(

  • Thanks Nicky!


    I'v been playing the last hour and it suddenly stopped. I guess it can't be the DSP failing...


    You're probablw right about line contamination. No I don't like my neighbour anymore!


    I'll check again tomorrow.


    Generall, it's really frustrating to have this issue as I'm not able to do something about it.

  • There you go, Yannick! Had a strong feeling that'd be it.


    No new appliances in your house? How about ones that might be getting old and "running rough"? I'd still suggest, next time it appears, trying it over at a nearby house, preferably not next-door but a number of houses' separation. At least this way you might be able to tell if it's something generated at your property or not.


    As for not being able to do anything about it, if you're unable to track down the source, you could always try a quality line conditioner. Good ones are expensive, but they can reconstruct the AC waveform so it's perfect.

  • almost sounds like a typewriter in the background. Have you tried to use the unit at a different location/house?

    Not yet... I tried different sockets everywhere in the house with the same result. Right now, there's no noise. But it comes back and disappears every now and then.


    I'm pretty sure it's got to do something with the the power line, probably related to grounding? I dunno. I'll try the device at my parents' place.


    And now whilst I'm typing, noise is back again...


    I'll also buy a new multi plug extension this pm. I'll try to find something with shielding.

  • I tried plenty of things (unplugging and re-plugging several appliances in my electrical network, switching off phones, switching off baby-phone) and nothing had a direct impact. The crackling stops and re-starts randomly.


    In order to rule out an issue with the Kemper, I still have to try it at another place. I'll be staying at my parents this weekend and try it out.


    If it really is the electrical network, the only possibility I see is buying a power conditioner. There's the Furman AC-210 A E which isn't too big.


    But before buying that I'll report back with next weekend's test ;)

  • So I still didn't try elsewhere (gonna do it this weekend) and noises are still there.


    I noticed however that the noise disappears when I use the in-between positions on my strat. I'm not a technical expert, but I guess that the in-between position is practically a humbucker (as it is using 2 pickups). That means that I definitely have something going on in the electric-magnetic area. It's just weird because I never had it since having the Kemper (4 months now).


    Several questions:


    • Is it possible that the wiring on the guitar is bad? I have the noise on all single coil positions (1, 3, 5), but not on position 2 and 4. If it was bad wiring, I guess it would be more likely that only one coil would be affected and not all three?
    • If it's an electro-magnetic field issue, will a Furman power conditioner solve the issue?

    EDIT:


    No other guitar at hand at the moment. So I just took the jack out of the guitar input and held it against my finger. I still cleary can hear the noise. I also just noticed that the noise is also present in the in-between positions; but only at a very low intensity. I guess that the humbucking position filters out most of the noise.


    Thanks for your input!

  • As ColdFrixion says definitely try it in an other location as soon as possible. Also definitely try it with another guitar. If positions 2 and 4 on a Strat don’t cause the noise that strongly suggests EM interference. The middle pickup on most strats is Reverse Wind Reverse

    Polarity making those two positions humbucking.

  • For the people that are interested (and because I don't like unfinished posts in which the original poster never posts back when a solution has been found) : It's definitely an issue with noise coming through the power grid. I checked the KPA at different places and never had any noises. I'm going to buy a Furman ac-210. Hope that it'll solve the issues.