Pickup Hum and/or Ground Loop

    I apologize if this has been covered already, but I didn't see anything doing a quick search. I run my Kemper through a powered mixer and into two passive speakers. I typically play a Hagstrom guitar. Historically I've had no issues with noise whatsoever, unless I to the coil tap and go to single-coil mode. When using the humbuckers, the rig was insanely quite! It was perfect.


    Yesterday I move the whole setup literally 5 feet to the left along the same wall, using the same outlet. All the sudden, the noise is terrible, even with humbuckers. I did note that when using a clean profile (gain very low), I the issue doesn't exist. It gets steadily worse as I turn up the gain knob in any profile. Also noteworthy is that the problem is the same whether I'm using headphones or the PA.


    To troubleshoot, I moved the Kemper to the other side of the room and the problem went away. I'd like to avoid moving the whole rig again if at all possible, for a few reasons.


    One other thing to mention is that the electrical breaker box for the house is now just a few feet away from the rig...I'm wondering if that's the issue. Lastly, I did tinker with the ground lift buttons on the back of the Kemper.


    Any ideas on the issue???

    When you moved the Kemper, did you also move your playing position? Forgetting ground loops for a moment, a fairly likely cause is that your pickups are doing what they do best - picking up noise :)


    To trouble shoot:-


    1. Select a problem profile with your guitar. Turn the noise gate all the way down. Listen to the huuuummmmmm.
    2. Turn the guitar's volume knob down to zero.


    If your hum is gone then it's not the Kemper's position that is the problem.


    In my little studio (I call it a studio to sound grand - it's a spare room with the fusebox way too close and a bunch of rockwool to make it sound better) I can cause terrible hum by simply turning my seat to face 'the wrong way'..... The amount it anywhere between 'fine' and 'horrendous' just by the angle I sit at. Thank heavens for revolving chairs :)


    If your hum stays loud and clear with the guitar volume down then you've got other things going on such as ground loop.


    Hope this helps as stage one of fault finding - good luck with chasing this down.

    I play with a strat with Lindy Fralin SC pickups.


    I have my entire pickup area surrounded with copper tape and grounded, but even then there are issues with noise sometimes.


    Recently, I noticed with some rigs that I was getting noticeably higher noise from my KPA than usual. As described in this thread, I turned down the guitar volume and found that the noise went away.


    That does not mean that you don't have a problem.... it just isn't with the KPA.


    My issue was caused by being plugged into a circuit with a computer plugged into it as well. This circuit also has some other loads on it. I found that plugging into a different circuit (not just a different socket) fixed the issue completely (whew).


    .... but then I got to thinking ..... what if I play a stage with noisy grounds? I did some searching around and ended up buying a Furman power strip with RFI and EMI filtering. Now even with my KPA plugged into a very noisy circuit, the guitar is very quiet.


    Keep in mind that no real single coil rig is going to be completely quiet in every orientation. This is especially true around light dimmer packs or florescent lighting (both cause lots of EMI in the air that is picked up by your single coils). This can be minimized by using shielding (copper tape) around your pick guard area (under the pick guard obviously ;) ).


    My rig isn't silent on high gain rigs, but it is fairly quiet (only a slight buzz even on very high gain rigs when using a SC).


    Hope this helps.

    When you move the rig around, are you moving closer to or farther from any specific lights/lamps, anything that can put out RF? I wouldn't know enough about the electrical panel, but I generally think that could be a possible source. Is it definitely a lower frequency hum, or a higher frequency hiss/noise?

    Thanks for all the feedback. It is more of a low hum as opposed to a high hiss. It does go away when I turn down my guitar volume, similar to normal hum when I plug my strat into my tube amps. It also does diminish when I find that sweet spot (angle).


    What I find puzzling is that it went from absolutely NO noise at all when using my humbucker pickups, to all of the sudden having terrible noise after I moved it a few feet down the wall. Also how it gets worse as I increase the gain seems odd (it gets REALLY loud as I turn up the gain past 12:00).


    I'll try using a long instrument cable and move to the other side of the room where I had no noise when I moved the Kemper over there and see if it still happens when I stand over there.


    Thanks again for your ideas.

    It can be as simple as now being near the wrong electrical circuit.... I used to get intermittent noise that drove me nuts. Turned out to be an energy saving light bulb in the hall. This was nowhere near my playing position but seemed to throw a lot of noise back onto the mains. Consequently, the socket I was near would give me hassle. Replacing that bulb with a newer LED meant better energy use and a problem solved :)


    As to distance? As an experiment, turn up your guitar and hold the pickups next to you computer, then move it back. A couple of feet away probably equals no problem but next to it? Weird squelchy noises may well be your reward. A few inches can matter :)

    I'm having the same issues, as soon i get close to the wall, it gets terrible. I shutdown everything in my house and nothing helped. It sounds like a ground loop issue. I'm contacting the electrician to take a look