FOH noise (Solved)

    Hey guys, So after about a week with the kemper I finally was able to setup e different rigs based on different amps at it sounds and feels amazing, but tonight was the first time I used the kemper live, I play in a church, the tones where really awesome but there was this really strong noise even when the volume on any of the rigs was off, I would describe this sound as ground noise or but when I switched the ground button on the back on or off it did not have any effect at all. I run the kemper out to a snake with then goes out to the mixer, I tried different channels and it was the same in all of them, and also didn't matter which rig was on or if volume all the way or 0...Anybody has experience this and knows how to fix it?


    the hum is very loud, the kind of loud that you can't ignore



    thanks!

    I had similar issues with my KPA. The static noise was present in all outputs (Both XLR and 1/4" main outs and monitor output) and it was loud enough to make our sound engineer very frustrated. I contacted Kemper support and provided them with some sound samples of the issue. I was told to send my KPA for repair. According to the service the culprit for the noise was "defective audioboard".

    Were you sending a direct line before you started using the Kemper?


    Does anyone else send one? If so, did they have the problem? If they are not having the problem, plug into the AC power they are using.


    If if no one else sends a direct line, you may have discovered a grounding issue between where the mixer is plugged in, and where you were plugged in.


    You may have to try plugging it into a different AC outlet.

    Thanks guys, From where I am in the stage right now no I have not used that power outlet before so Ill try changing to a different one. Before I was in the other side of the stage and the base player and me when I used the axe ultra went direct and never had any issues with noise. The thing is that in my house I use the same output to plug in to my power speaker and it does not give me any hum noise at all, its completely clean. Did the same thing happen to you Weetm? This sunday ill plug to a different power source like Paults suggested but if it still happens I might have to exchange it for another one since I'm still under the 30 days.

    Quote from julindres

    Did the same thing happen to you Weetm?


    No, the noise in my KPA was present regardless of the environment. When playing at home I didn't notice it that much because I usually play at relatively low volume. On recordings it was clearly audible, though and in the gig situation with louder volume levels it was really annoying.

    I agree with Paults. If it were an issue with your Kemper, you would likely have this noise regardless of where you plugged in. But the fact that you're not having it at home, but having it in another location, points toward a grounding issue.


    From my experience, it's always best practice (when possible) to plug all of your rig into one outlet. So for exmple, don't plug a powered monitor into one outlet and then your Kemper into a different one. They may be on different circuits and that could lead to a grounding issue.

    It's not clear to me if you are hearing the typical 50 (60?) Hz "hum" or something different :)
    Anyway...


    Are you using a balanced (XLR) cable to go to the mixing desk?


    Another thing I'd check is whether the mic preamp is switched off for the mixing desk's channel you are using.


    What is your output level set at (in dB)?

    I ran into something similar to this at home the other day right after upgrading to 3.30 as a matter of fact.


    Seriously loud hum from my studio monitors. I was going crazy trying to figure it out. Checked the usual suspects - noise gate, cables, other inputs on my interface, etc.


    I then turned off the Kemper and turned it on again... and the problem was gone. I have no idea what caused it.


    Next time this happens, do try to switch off the unit and switch it on again, might resolve such a problem when you're on stage, though boot up time can be vexatious.

    Agreed Gianfranco, but rebooting doesn't fix it; that was what happened in nightlight's case. The OP hasn't said whether or not he's tried that.


    The OP mentioned that it didn't happen when he was on the other (usual) side of the stage, so I'm figuring it's a grounding issue with the power outlet he used, which might be "solved" with the switch. This assumes the Kemper's OK, 'cause he was using an Ultra when positioned on the other side, both literally and figuratively(!).


    It goes without saying that when it comes to electronics, I've no idea what I'm talking about. The suggestion only came to mind 'cause it was a button that hadn't been pushed yet in the OP's attempt to fix the problem.

    Quote

    rebooting doesn't fix it; The OP hasn't said whether or not he's tried that.


    Not sure I follow your logic here Nicky ;)
    it seems that we just need more information :D
    Meanwhile, every trick may make the boat float... ^^

    Quote from viabcroce

    Not sure I follow your logic here Nicky ;)
    ^


    Well, I did say that "that was what happened in nightlight's case" and that the OP hadn't tried it... hang on...


    You sneaky bugger, Gianfranco. You cherry-pickin' quoter, you! LOL


    Quote from viabcroce

    ... it seems that we just need more information Meanwhile, every trick may make the boat float... ^


    Agreed. More info would be good.


    Being a silly poke-it-with-your-finger-and-see-if-it-bites type of monkey, I'd have pushed the Ground-lift button for sure and as you say, "every trick may make the boat float"...

    Thank for all the advice guys, This sunday I will play so I will try a different outlet or try to see what else I can try or change, I have lower the sound of all my profiles in performance since the kemper sends a really high signal, My output volume is currently set at -20db

    Quote from Monkey_Man

    Being a silly poke-it-with-your-finger-and-see-if-it-bites type of monkey, I'd have pushed the Ground-lift button for sure and as you say, "every trick may make the boat float"...


    :thumbup:


    I'm rather the "mhhh... I want to know more about it before I poke that" kind of guy :D
    But in this case I'd push that button too... I've read the manuals, I know it doesn't bite...
    ... unless all the others were pushed and it was not (might actually bite)


    :D



    Quote from julindres

    This sunday I will play so I will try a different outlet or try to see what else I can try or change, I have lower the sound of all my profiles in performance since the kemper sends a really high signal, My output volume is currently set at -20db


    Sadly you did not give any answer to the many question... hard to be of help if not for a hit of fate :)

    I don't think the hum is the 60 hz hum. I used to own an axe ultra and went direct and never heard this kind of hum. As far as the preamp I have to wait until sunday to check how the sound guy has it set up. And yes I I'm using a balance cable. At home I can't run it up too loud but I checked and when the kemper is connected the hum is a bit louder than the normal speaker hum, so it might be when the signal is amplified, Il try rebooting it if it happens on sunday, I will also take power conditioner to plug the kemper so if its that hen that should fix it. The ground button on the back made no difference on the hum wether on or off.

    If you output -20 dB and the sound is "very loud", chances are the mixing desk strip has a mic pre engaged. Some can't disengage it unless you use a 1/4" plug... It might be worth a try.


    :)

    Good point, Gianfranco.

    Quote from viabcroce

    :thumbup:


    I'm rather the "mhhh... I want to know more about it before I poke that" kind of guy :D
    But in this case I'd push that button too... I've read the manuals, I know it doesn't bite...
    ... unless all the others were pushed and it was not (might actually bite)


    Ha ha ha... I'm actually like you too; I don't believe in pushing blindly. I was just havin' a laugh at my alter-ego's expense. He's a simian. He represents all that is silly about our natures. Impatience, ignorance, incompetence and so on. I like to put myself down (self-deprecating nature), so I often describe myself as I did in that post. In that case, I was imagining being in the OP's position and not knowing what to try next, so I suggested giving in to that part of us that resorts to "blind" poking and prodding in order to get something to happen when nothing else works. I'm so very careful I can't think of the last time I did this, but, being human... I mean, simian, I'm aware deep down in the bowels of my mind that the option's always there should all else fail, which it usually doesn't.


    Research and considered actions are hard to beat in the real world IMHO, and it's generally the "lucky" types (and foolhardy, an all-too-common combination) who resort to this sort of action at the first sign of trouble. I'm thinking kid in a candy factory, pokin'', proddin' and pushin' buttons in the hope of scoring the mother load of lollies. Monkey Man likes this; it's his way I reckon. I only defer to his way as a recommended course of action (such as this one) as a last resort.


    Phew! Well, we'll all sleep better tonight now that we know that. Not! :D

    Hey guys, so after checking two times the noise came from the mixer, its a digital berhinger x32 and what we had to do was to bypass the eq, that seemed to solve the problem, the noise was gone. Now some of the patches sounded really nice but some of them i need to work on....Its kind of weird some of the overdrive tones I got sounded almost clean today, its usually the other way around I usually have to turn gain down but on this case it seems like for most low overdrives i need to add more gain, I also got to work a lot on the delays, seems like at home i was getting some nice ones but playing live I could barely hear them...


    thanks for the help everybody