How do you get rid of electrical noise on stage? SOLVED

  • My KP gig setup is usually very silent, but, in a new stage I am hearing electrical noise.

    Maybe the venue's AC supply is poor, the outlets are not earthed well, the lights, etc..

    Only when the guitar volume is down the noise is gone.


    Just in case, I've tried isolating the usual suspects from my gear, by keeping it simple, just guitar/kemper/headphones; zero gain profiles (Kemper factory rigs); different shielded guitars (no single coils), different high-end shielded guitar cables. I've tried RFI and EMI filtering like Furman power strips, but the noise is still there.


    - Could you share some tips to deal with "noisy" stages or bad electric conditions and Kemper?

    - What device would you recommend to kill any electric static noise, ground loops, AC noise/hum, electric magnetic interference, etc. in a single box?

  • Hellu.

    Is it only your gear having this noice or does other guitarists

    in your band or other bands have the same issue ? :/

    If so, maybe there´s some electrical problem on that stage / venue ...

    And if that´s the case, tell the owner to check it up .....

    Safety first ! Don´t fry your equipment or yourself !

    Just sayin´ .......


    Cheers!

    The adjective for metal is metallic. But not so for iron ... which is ironic.

  • Depends what you're connecting to - sometimes a DI box between your KPA and the P.A. can help, since it separates the KPA from the rest of the setup. It's a bit overkill (DI is supposed to make an unsymmetric signal symmetric, while the KPA already delivers symmetric output), but the galvanic separation can definitely help on any ground noise issues.

  • try moving it to a different place on the stage . Sometimes that noise is cause by being in proximity to something else. Also, I always take a simple Circuit tester in my gear bag, to make sure the wiring is correct at the venue, I've seen the Hot and Neutral are reversed at an outlet

  • Thank you guys for all your suggestions.


    I followed your advice, except Wheresthedug’s “noise killer” 8o


    1) I am not sure if KP Ground lifts would help in this case. Remember that during my early tests, the noise appears, even with nothing connected to the KPA but the guitar and headphones. I do have a KPA Head, by the way.


    Anyway, since Live I use all the outputs, just in case, based in your advice, now I have all GROUND LIFT buttons pressed, except DIRECT OUTPUT. From the manual (pages 71 and 224): “At least one GROUND LIFT button must be off at any time (which means ”grounded”). Often you get best results if the DIRECT OUTPUT is the one connection with no ground lift.“ :thumbup: Hope this prevents further potencial issues.


    2) I’ve made additional tests today. I believe this venue has some issues. Daylight sound check, no noise at all. 7/8PM the noise appears but with less intensity than previous day.

    The noise disappears using the Global Noise Gate at 0.1 (at least today):thumbup:

    Edited once, last by Syntek ().

  • Depends what you're connecting to - sometimes a DI box between your KPA and the P.A. can help, since it separates the KPA from the rest of the setup. It's a bit overkill (DI is supposed to make an unsymmetric signal symmetric, while the KPA already delivers symmetric output), but the galvanic separation can definitely help on any ground noise issues.

    Do you mean something like this?

    - Behringer MicroHD HD400 Hum Destroyer

    - Ebtech HE-2 HumEliminator

    Does it color the sound?

  • Only when the guitar volume is down the noise is gone.

    Your sentence says 'It's the guitar Pickup" that get Hum from an EMF.

    Try to detect the EMF source using an EMF Meter or EMF Detector.
    The Venue owner should help to fix that, because it will have impact for every Live-Band.

    Be the force with you ;)

  • Your sentence says 'It's the guitar Pickup" that get Hum from an EMF.

    Try to detect the EMF source using an EMF Meter or EMF Detector.
    The Venue owner should help to fix that, because it will have impact for every Live-Band.

    That!

    You stated earlier that you even have noise with only guitar and headphones connected. Thats a situation where you can not have any ground loop, so ground lift switches are not the solution (well, doesn't hurt to try to flip em and hear any difference....). But there are other noise sources:

    * A bad power supply, for example noise that is injected on the power source by dim packs. Allways try to have your lighting, fridges, and other heavy equipment electrically as far away as possible from your sound equipment: ie by having a totally separate 3x380V cable to the generator for your sound equipment. A power conditioner can help, but be carefull with like 12V to 230V converters. My Kemper particularly does not like my campers battery power! noise all over te place!


    * EMF... We guitarists are proud to use technology from the 50s, but it's very very flawed. Those pickups are antennas. For example, when my robot lawn mower starts to do my lawn a get all sorts off noise through my cans, and this gets worse when a switch to high gain, is muted when my guitar volume is rolled to 0... That lawn mover is battery powered, completely wireless, so that noise can't travel through ground or live wires, the EMF noise is airborne....

    PS: ground lifts make ground loops better but EMF noise worse... Wires can act as antennas...

  • Do you mean something like this?

    - Behringer MicroHD HD400 Hum Destroyer

    - Ebtech HE-2 HumEliminator

    Does it color the sound?

    Yep, those should do the job - that is: if your problem is caused by a ground loop. So if you have a nice and solid 50Hz hum, then those beasts can save the day. Sometimes, they also work on "chirping" high-frequency noises, especially coming from connecting a laptop to a PA.


    What they won't help you with are other phenomena, like e.g. "microphonic pickups" or electrical interference going into your pickup (e.g. lighting interfering with single-coil pickups - humbuckers have a definite advantage there.


    It never hurts to have one of those little boxes in your kit bag - you never know when you'll need them. Don't forget to pack XLR to TRS adapters as well (both male and female XLR).


    To normal ears (as opposed to "golden" or "bat ears"), these adapters won't color the sound - nothing you'll hear in a live context anyhow.


    Cheers,

  • Yeah, exactly. Ground lifts and DI Hum killers are very useful solutions to have at hand. In this case they won't make any difference, based on the source of this noise.


    About EMF, EMI, RF,potential airborne sources and the relation with the pickups. I don't have an EMF meter, but I did a basic test, no guitar at all: Kemper + Headphones + high quality cables (Mogami shielded gold contacts). I did ground the static noise by touching the connector (not the contact tip). Same result: during daylight no noise, at night the noise was back and I had to increase the noise gate around 3.0 to get rid of it.


    So, as we all mentioned above, the source might be noise injected from poor power source. In fact, I see what you described, all over this place: dimmer illuminated pop art pieces, some neon lights, ceiling air fans, and cold beer in a refrigerator in the bar close to the stage. Nice and cozy place, but an electrical haunted stage. The owner needs to check this, for sure.


    I will test a power conditioner, soon. Meanwhile, my workaround is drink some beers and add a bit of KP global noise gate!! Noise gone.