Revenge of the crackling/buzzing sound

    I've already sent my KPA in for repair for this issue once before and they replaced my DSP board and said everything thing should be fine. Unfortunately, it's not. On my high gain patches, I get a horrible buzzing, crackling noise. I thought it was related to the electricity in my house but I took it to my dad's house and it was making the same sound. Here is an example clip to show you what I'm talking about: Clip


    The first section is with everything plugged in as normal. The signal chain is KPA -> Presonus Inspire 1394 -> PC
    The second section is with the KPA plugged into a Furman PL-8C and everything else plugged into the usual power strip.
    The third section is with the entire signal chain plugged into the Furman PL-8C.
    The fourth section is everything plugged in as normal, but in the middle of it, I raise the noise gate from 3.0 to 6.5. It helps the ringing out of the noise, but the buzzing is still coloring the guitar tone.


    I used palm muted chugs because they most prominently display the crackling noise, but it also happens when playing normally. It's frustrating because I paid so much money for this machine I can't even enjoy playing because this noise drives me crazy. Can anyone offer me any insight?

    ok to me this sounds like pickup noise , its noticeable when you let chords ring and the guitar volume knob is up , i get this issue also with different guitars it changes. Try moving around the room while you play , specifically away from noise sources , move the guitar away from even the kemper itself and your computer and audio interface and see if the noise changes. If it does its just noise from your pickups and its a problem with high gain and certain guitar pickups

    Thanks for your response. I've tried different guitars, different cables, different power strips. I've tried moving away from the unit and the sound is consistent. I've tried unplugging the input cable and turning off the noise gate and the crackling is there.


    I know a bit of noise is natural in high gain amps, as I've owned several, but the noise my KPA is making does not sound normal. Even my wife was walking by while I was playing and said "what is that awful sound?" (not just my playing :P )

    Try turning the master volume down, maybe below 7.
    Don't know if it's normal, but it happens in my unit as well - the main PL output overloads inputs. The XLR out does not.

    "But dignity is difficult to maintain
    stamina requires constant upkeep
    repetition is boring
    and you pay for grace."

    Alright guys, had some time to sit down with it again. Tried adjusting the master volume, that didn't help with the sound. Tried with headphones and it also makes the sound. Even on a clean sound, if you ring out a chord, you can hear a strange static come in. The noise is a bit reminiscent of a sine wave LFO filter the way it comes into a ringing note.


    Also, HELL-G, I think I know what you mean about the XLRs. When setting up my KPA to record into my interface initially, I had to drop the KPA volume significantly, because even though my levels were showing green on my inputs, it was clipping hard when playing into the PC.

    I've tried many different guitars, to the same result, and all of them have passive pickups. I've played with the pickup height and that also made no difference.

    So I guess I have no choice but to open a new ticket with support. I've been emailing with the guy who worked on my KPA the first time and his answers were to try a ground lift or a power conditioner. Nothing so far has solved the problem. I wish there were a simple solution, because it sucks to not even want to play this great machine I paid so much money for because of the noise that it makes, and I certainly don't want to contact tech support just for the fun of it.


    Can someone please confirm that the sounds in my recording are not typical before I contact support again?

    If you can post the rig you used for the clips, I can try to replicate later. I can't remember hearing that sound.


    It does seem like interference or a bad cable of some kind - not bad enough to destroy your tone but it does seem to seep in as you sustain. But if you're getting it on multiple guitars, in multiple homes, with multiple cables, using headphones plugged directly into the unit...


    Turn the noise gate completely off. Is the sound ALWAYS there? Or only when you feed the Kemper some signal? Can you post a clip of this happening on a clean patch?

    At times the noise is actually audible over the guitar notes, but it hasn't done it when I've been recording test clips to show you guys.


    I did unplug the input cable and turn off the noise gate and it does make noise, but I think it's made worse when the guitar is feeding it signal.


    When I get off work I will record the noise it makes with no noise gate, with and without guitar signal, and I will record the noise that washes in at the tail of notes on clean sounds. Is there anything else it would be helpful for me to record?


    The rig in the first 3 sections of my demo clip is Chris Munday's Cobra Crunch link , and the last section is Thomas Van Beeck's TOTW 04 link, just with a noise gate, and some slight EQ to roll off the extreme highs and lows.

    That does sound very much like EMC ,, have you tried without a computer on, just kemper and cans ,, i have a simular problem when my mac pro is on,
    I have to put the mac outside the room and plug it in to a filter, but as soon as i hook up the input to the fire sound modual which is seperate and use a hi gain preset , i can still hear chatter from the mac, if i then run a program on the mac it gets a lot worse,,
    Only happens on hi gain presets,
    Hope this may be of some help

    Steve
    Mainly my own built valve amps and Kemper

    sorry i didn't get to test the patch yesterday.


    the first half of the clip is with no instrument cable connected? It sounds like there's a hum that punches in and out like when you touch the tip of an instrument cable.


    Have you tried outputting to your interface via SPDIF if available? I'm wondering if the outputs have a short or something like that. And back to the point made above, have you tried listening through headphones with the KPA completely disconnected from the interface/computer?

    Some questions:


    Does the noise disappear when you turn down the volume pot of your guitar?


    What is the gain setting of the specific rig?


    Do you use additional booster or distortions in this rig?


    Do other rigs (factory rigs e.g.) produce the same noise?


    -The noise is only there when playing, unless I turn off the noise gate. When the noise gate is off, the sound is reduced by turning down the volume pot, but not eliminated.


    -In the rig I've been using to demonstrate, the gain is at 6.2


    -There is a green scream in slot A on the rig I used to demonstrate, set at Drive 2.0 Tone +0.3 Volume +0.7. Disabling the green scream does reduce the noise a bit, but it dulls the tone, and the noise is still there.


    -The noise is most prevalent in very high gain rigs (including factory ones), which is unfortunate since those are the main ones I use! It seems the more gain on a profile, the worse the noise gets (an obvious conclusion, I guess haha).



    and for meambobbo, I took it to another room and plugged into the outlet on the brand new breaker and tried with headphones. It actually seemed like the noise was worse out there!

    Now after 6 days without an explaination, the boss has to fix it :)


    All that noise sounds very familiar to me, nothing special. Welcome into the guitar world. :)


    Your amp with gain to 6.2 is not really high gain, but you add the Green Scream with the maximum treble boosting (your Tone setting), some additional drive and some volume.
    This adds to a reasonable high gain sound with loads of treble boosting of the hum and noise of your guitar.


    Adding "treble boosting" with a tube screamer into a gained amp will amplify the guitars hum and noise in the way you can hear on that clip.
    Finding that out is no rocket science. Just turn some knobs to see where the noise rapidly goes down. That's the parameters that emphasize the noise. You might find the Green Screamers Tone knob controls the noise by a great impact.


    You will have to overthink your Tone setting for treble boosting, unfortunately.


    Now if somebody thinks this would not happen with real amps: I have a Marshall rigged up at the moment and I made the same test with a real tube screamer and similar settings.
    Same result, same noise, same hiss. Awfull. And I did not even have a noise gate to turn on :)


    People might have had this problem 40 years ago with contemporary equipment. No need to send your Profiler back for repair.

    Thank you for your prompt response CK. The only reason it makes me panic is because I did not have these issues when I first got the KPA. Even the tech who worked on my KPA said he could not get it to make the sound in my recordings. I also have rigs with much higher gain settings and an OD in front that don't make the noise as severely. But if you say this is normal, then I guess I just have to tweak my settings until I can get that noise to a manageable level. Thanks again.

    If you didn't have these issues first, then you might have used a different setting, or you weren't that sensitive at that time.
    As I said, you have the same trouble even with the analog pendants.