Problems with grounding buzz

Did you try to push one of the ground lift buttons on the back? Is the line frequency on system menu set to auto?

Also make sure that your guitar is grounded properly and stay away from computer screens/neon lights

What lights do you have in your garage / nearby?

Reason I'm asking is that it could be airborne interference. If you get a considerably quieter signal when you touch the bridge of your guitar then that says to me that it's your body acting like an aerial for all the airborne noise. When you touch the bridge, all that energy goes to ground and things improve.

The worst things for this? Fluorescent lights and dimmer switches. Nearby computers can also give you a different kind of high-frequency 'chatter' noise.

As an experiment, take some candles or battery operated lights in there. Turn off not just every light in the garage but every light in the house. Might sound crazy but stick with me!

See if it improves. Then turn on the lights one by one and see what happens.

I also play in what used to be a garage - it's built in to the house here and long ago was converted into a room. I had installed LED lighting (which has given no issues) but I was *still* getting bad problems. It was actually the energy saving lightbulbs (fluorescent) which were in the hallway. Now these are a good 12 or 13 feet away with a cupboard and a brick wall between me and them but they still did it! Both these kind of lights and dimmer switches can put all kinds of crap into the rest of the wiring and, even if your lights are off in the garage, you could still get issues! I also got a lesser issue from the kitchen which has halogens but a dimmer switch. It's a looooong way away but it still caused me problems!

I solved mine by replacing the hall lights with energy saving LED. Brighter, cheaper to run and no noise issues.

Another thing I always do is screen by guitars. The body cavity on a Strat and the back of the pickguard can be treated with taylor made material or, in my case, turkey foil It does make a significant difference to this issue but check out the lights first.... if you live with candles only in the house and still have an issue then I don't know what to suggest and the guitar screening is unlikely to make you happy.

Good luck with solving this - noise drives me absolutely nuts.

Have you tried to unplug the mains contact and rotate it 180 degrees and plug it in again?

Ideally you want a type of "Star grounding" system.

Theres lots on google on this, but in essence, you want everything you have routing back to the same power ring.

Or in much simpler terms, to get this, instead of using different plug sockets in your garage, get a multi-plug adapter, and plug everything into that, and the adapter into ONE of your power sources. This way, everything is guaranteed to be on the same ring - ie., connected to the same grounding point.

There is more detail to it than this, but this is good enough for most. If the buzz remains, you may have a ground loop problem. So try to plug into a different power outlet in your house. If it remains, then your entire circuit may have a ground loop problem, for which you'd be best calling an electrical engineer out to your house to resolve it.

Of course, it could be your gear, so maybe bring it over to a friends house and see if it still buzzes there (and that their gear doesnt, to make sure that THEY dont also have a grounding issue). If it doesnt buzz at their house, then your gear is fine.
If it still buzzes, then your gear may need a service.

EDIT: Oh and some may suggest on forums to remove the grounding pin.
UNDER NO CIRCUMSTANCES SHOULD YOU EVER DO THIS!!! IT IS EXTREMELY DANGEROUS AND A BUZZ IS NOT WORTH YOUR LIFE!!! (Not to be overdramatic, but electricity can (And does) kill! - be safe with it! )

I had some buzzing to with my Dxr15 so I connected it using a TS to XLR cable. Now it's silent. I use monitor out with no ground lift. Try that and see if it helps.

I think is the neutral that is on the phase side and the phase is on the neutral side of the mains net, so if you rotate the mains plug 180 degrees, perhaps this will solve the problem.
Other thing is also that the signal cables should not be next to the power cables, this will cause buzz, interference from the power cables to the signal cables.
A good doulbe shielded cable is also good to have.

In my experience, this is always an electrical problem, rather than a problem with the Kemper.

It might be a bit expensive, but if you get a power conditioner of some kind, you should be able to kill that hum. Alternatively, if you can have the problem electrical sockets isolated and properly wired, the issue should go away. Neither is cheap, but in the long run, this is the best solution.

Yup try a power conditioner, I haven't been without one in years. They can be picked up on ebay for around $50.

If the hum dissappears when you turn your guitar volume down, then it's no ground loop.

Hopefully on topic enough...is there any reason that rack mounting my Kemper (rack model, to state the obvious) will have increased the noise floor? I mainly just use it sitting on my desk with headphones when I'm at home and ever since I put it in the SKB Roto X rack I got, I swear the hum and noise has increased. The grounding switches have no effect on this, but it may be worth mentioning I also have it plugged into my interface via TRS 1/4" on the main outs. I first thought maybe some additional plastic washers would help, but the screws will still make contact yeah?

Quote from DrDreas

Hopefully on topic enough...is there any reason that rack mounting my Kemper (rack model, to state the obvious) will have increased the noise floor? I mainly just use it sitting on my desk with headphones when I'm at home and ever since I put it in the SKB Roto X rack I got, I swear the hum and noise has increased. The grounding switches have no effect on this, but it may be worth mentioning I also have it plugged into my interface via TRS 1/4" on the main outs. I first thought maybe some additional plastic washers would help, but the screws will still make contact yeah?

It is on topic, and my previous post has answered your question in advance.

In other words: if you turn down the volume on your guitar and you hear no noise, then there is no grounding issue.
If there is residual noise, you have a ground loop.
All the noise that you turned down by the guitar volume came from your guitar.

Single coil pickups will always pickup noise since they are essentially unshielded antennas. There are ways to lower your noise by using shielding inside your guitar. There are kits made for this, or you can make one yourself with aluminum foil and spray glue. I have a little 60 Hz buzz going on in my strat that has Lindy Fralin pickups in it. Nothing horrible (for single coils), but just the same, I am going to install a shielding kit on it to reduce it to a minimum.

You can never eliminate the buzz entirely since the pickups themselves are part of the problem, but you can get it so low that it really doesn't matter any more.

If anything, I have found that the Kemper has raised my awareness of my buzz since I now have rigs that bring out the noise more than my old tube amp did. Some rigs are nearly immune to it, while others amplify the 60 cycle buzz quite a bit.

It isn't likely the kemper though.

Right said!
There is two possible reasons that you get more noise on certain rigs than you got from your old tube amp:
More gain, or more high frequencies from boutique amp profiles.

Had same buzz problem in the studio we were recording in yesterday. Have had KPA for a year and never had this problem elsewhere so clearly something to do with the electrics in the studio. We tried most of the approaches suggested above but made no difference. Only thing that worked was grounding me in some way - hand across all strings got rid of buzz but needed to be all strings so if played a 3 string chord then buzz still there. As it seemed to be a grounding issue we tried it with me sitting on the KPA and it worked! Was able to record the rest of the day with no buzz as long as stayed sitting on the KPA but if removed butt from KPA the buzz returned. So can now report that the KPA in addition to being the most amazing piece of kit on the planet is also strong enough to support 70Kg guitar player for at least 8 hours. By the way also pleased to report I didn't have to remove my pants to achieve the grounding.

Yes - the thing that made me say 'airbourne' was the OP saying that touching the bridge on the guitar improves the problem.

Quote from ricky50

So can now report that the KPA in addition to being the most amazing piece of kit on the planet is also strong enough to support 70Kg guitar player for at least 8 hours. By the way also pleased to report I didn't have to remove my pants to achieve the grounding.

I nominate you the Kemper tester of the year. Seminal conclusions from your research.