Getting rid of ground loop buzz with Axe fx and Elec. Guitar. Good way of fixing it?

G

Guitarplayer490

Member
Okay so I have found the problem on why I'm getting feedback after I stop playing with my electric guitar and my Axe fx 2. When I'm playing, especially distorted, on any guitar I have with active or passive pickups, I get that feedback buzz. I've asked around here, as well as doing some research, and I'm positive my patches do not have too much gain, too much master volume or anything like that. I've tested the cable, switched it out with other cables, switched guitars with it, and that's not the problem either.

I think my problem is ground loop buzz and/or EMI feedback. What I am doing now to try and fix this, is to put some copper conductive tape in the cavities off all of my guitar, after a user on here linked me a video on how to fix ground loop buzz. I am also going to clean the pots on all my guitars, as I have heard this contributes to the sound.

The last thing I am going to do to ensure I don't get any unwanted feedback, is to buy an Ebtech Hum X, and put it on my power strip. The problem I have though, is I don't know what could be causing the ground loop buzz, so I don't know which electronic I should plug into the hum X. Currently, I have my Axe fx 2, Desktop computer, computer monitor, and external hard drive as part of my studio setup. I saw a video on a user that bought it, and he plugged his laptop cord into the Hum x, and all the hum was gone. I am wondering if I should plug in my PC into it, which is what I think I should do, or if I should plug in my Axe fx, or something else in it to eliminate the ground loop buzz? Thank you.
 
Guitarplayer490 said:
I think my problem is ground loop buzz and/or EMI feedback. What I am doing now to try and fix this, is to put some copper conductive tape in the cavities off all of my guitar, after a user on here linked me a video on how to fix ground loop buzz. I am also going to clean the pots on all my guitars, as I have heard this contributes to the sound.

The last thing I am going to do to ensure I don't get any unwanted feedback, is to buy an Ebtech Hum X, and put it on my power strip. The problem I have though, is I don't know what could be causing the ground loop buzz, so I don't know which electronic I should plug into the hum X. Currently, I have my Axe fx 2, Desktop computer, computer monitor, and external hard drive as part of my studio setup. I saw a video on a user that bought it, and he plugged his laptop cord into the Hum x, and all the hum was gone. I am wondering if I should plug in my PC into it, which is what I think I should do, or if I should plug in my Axe fx, or something else in it to eliminate the ground loop buzz? Thank you.
Click to expand...

Logically, you should plug all equipment behind such type of protection if you don't want any ground hum coming through the mass of one of your equipments that would not be protected. If you're using good quality equipment (ie galvanically isolated inbuilt power supplies and all plugs I/O isolated from ground) this should be no issue however. I use the axe without any additional artifices with no significant problems wherever.

What guitar you use & what PU -> HB, SC ? Once you screened the inside of the guitar, do take care of following : interconnect by wire soldering all metallic masses to mass of the input jack, bridge or tremolo system, metallic housing of the volume and tone pots, mass of input jack. Impedance of shielding is not always very low depending on what cavity shielding material you use (graphite spray, copper spray, or copper foil) and inter connecting the masses therefore can make a huge difference beyond cavity shielding.

If the problem persists try to use just a simple an unearthed power plug to isolate any "polution" coming into your electronics from the earthing of your electrical installation. However never ever experienced such problems with Axe Fx on stand alone basis (did have when using Axe Fx as effects box only through two tube amps, and this resolved the case). If this works then better be sure the power circuit you are using is protected by an earth leakage device for personnal safety. Playing close to old neon lighting armatures is not recommended, but when guitar is correctly shielded this should not influence too much however.

Courage, hold on !
 
I get the same thing with my ESP on my high gain patches. it shits me. The hum is always there it is just most noticeable when you stop playing.
 
If you want any info on the Ebtech products, let me know. I use two of their 2 channel units, and one of their 8 channel units (that also converts -10db to +4db). I no longer need them in the studio, but have them here to test or sell.

Pete
 
You still have not mentioned wether you tried a different guitar?

Before you go buy some expensive transformers or anything like that, try to find the thing in your rig that is causing this.

I'd start by switching the guitar,
then removing USB connection or let the laptop run on battery (a laptop on battery is powered by DC, not AC),
then disconnect any stuff between your monitor and your Axe,
then try using headphones instead of a monitor,
then try to connect your rig on a different power circle (go to a friend's place or something),

and THEN, FINALLY, I would go ahead trying a transformer, if nothing of these helped.
 
Hum is caused by your guitar pickup up magnetic interference from something in the vicinity. Transformers, fluorescent lights, dimmers, etc. create magnetic fields which your guitar will pick up (since it has magnetic pickups). Remove the offending devices or move away from them.
 
^^^ Bingo.

It's a difficult, but common problem. Go the EMG route, or try other good passive noiseless pickups. Make sure your guitar is shielded and very well-grounded (star-grounded). Check out guitarnuts.com.
 
In our house, dimmers are the main offender. There's also a noisy street light in the alley behind our house. The noise is always worse at night.

It's particularly bad in the winter, when the air is drier which means less water molecules (why you get shocked when touching the door handle (like Peter Gibbons).
 
Divide and conquer. You have to start eliminating possible sources of the noise until you find the one that is causing it. Listen to the frequency of the hum. Does it change? Mains noise is a fixed frequency. US mains is 60hz and most everywhere else is 50hz. Changing hum frequency usually means you are picking up something else like radio interference. Here are some things that can cause hum:

the mains wiring - if not properly wired and grounded, your entire house's wiring can act as an antenna for noise. Plug in somewhere else and see if the problem follows you or stays at home. You might have to call an electrician for this one.
nearby electronics - PC's, TV's and monitors (especially old CRTs), fluorescent lights, dimmer switches on lights and fans, appliances, etc. all emit EMI. Move things around to find a quiet spot, or play inside a faraday cage.
power and signal cables run too close together - keep power cables as far away from signal cables as possible and don't run them parallel to each other like in cable bundles.
wiring on your guitar - check the ground wire going to the bridge on electric guitar. Shielding tape or paint in guitar cavities can help. Use shielded wire for longer wire runs inside the guitar too. Use humbuckers.
bad cables - check shield connection to the plug ground on instrument cables. Use quality cables that have a really good shield.
rack ground loops - sometimes the rack itself causes a ground loop by physically coupling one rack device to another. Use non conductive spacers like Humfrees tabs to isolate the units from the rack and each other.
cable ground loops - cable routing for things like pedal boards and effects loops are notorious for causing ground loops and hum. Isolation transformers can break the loops and stop the hum. Balanced cables can eliminate hum much like humbucking pickups do.
device specific issues - If all else fails, the hum could be coming from the Axe itself or some other device internally. Call support if that's the case.

Test each part of your rig one and a time and you'll eventually nail down what's causing it. It can be a real pain in the butt and very frustrating.
 
Putting together a Humbuster cable did wonders to my hum problem. I live next to a train line. The noise was there even when no guitar was plugged in. And now - dead silence.
 
I had a similar problem for months and it drove me crazy. To fix this issue I started using noise gates to help deal with the noise a little bit when I stopped playing. I place a noise gate at the front and end of my chain and it usually does the trick. Just make sure not to choke your tone too much. I'm not able to move my computer equipment and such, so this was what finally worked for me. Might not work for some, but 'tight tone+minimal noise=win' in my books.
 
The bottom line is the noise can come from a variety of places. Listen for the type for interference you are getting. Is it low frequency, is it high frequency? Does it change when you move your guitar. Is it a steady low hum? Mr. Fender's advice is great.

If it changes when you move your guitar, it is like coming from some device in the Area putting out an EM field (transformers, dimmers, CRT monitors, lots of things). Try to eliminate the source of the noise if you can. If not, lots of shield and find a place where it interferes the least. Humbuckers can help. noise gates can eliminate it when you are not playing.

If you are get high pitched whining or clicks it can be from things like cell phones to computers. It happens to me a lot with USB connections. I have a USB isolation former for devices that do not need hi-speed USB and are causing high frequency noise. I've had some luck (but not always) with USB cables with ferrite cores on one end as well. Many time by using an isolation transformer on an audio connection can stop the high frequency ground loop as well. My I pad which was connected to my MIDI USB device and its audio out to my DAW interface caused high frequency interference. A isolation transformer between the ipad audio out an my DAW interface corrected the issue.

For the typical 60/50hz ground loop hum. Proper rig wiring ensuring only one patch to ground is the best way to keep it from happening in the first place (be sure you plug all interconnected devices on one circuit). Short of that, ebtech Hum X can eliminate ground loops if you put it on the right device, ground lift switches on balanced connections can help. Isolation transformers can help to eliminate group loop hum. (make sure to avoid impedance mismatches that will dull your tone - i.e. plug your passive pickup guitar into an ebtech hum eliminator then into your amp ). Humbuster cables with Axe-fx can do wonders for eliminating 60/50 cycle hum.

Other things that help reduce interference is to keep your cable runs as short as possible and not run high-power cables in parallel and close proximity to long audio cable runs. If you have to cross audio power cables, try to do so at right angles.

There are quite a few articles out there from reputable source on reducing hum and other types of interference. I would read as much as I could on the subject. It will save you a ton of time in the long run.
 
Your jack cables should not lay on top of adapters etc. Have run into hum at gigs. Turned out that my guitar cables was passing a adapter for a pedal board.
 
Kriig said:
Your jack cables should not lay on top of adapters etc. Have run into hum at gigs. Turned out that my guitar cables was passing a adapter for a pedal board.
Click to expand...

Or really close where the power supply transformer is for rack gear.
 
You must log in or register to reply here.
Back
Top Bottom