Grounding issue?

[Sly Fox]

Playing a gibson es through vox ac15 and have an intrusive buzzing most noticable when playing clean. If I load up the rat pedal and play high gain some hum and hiss when not playing is acceptable but on clean it makes the amp totally unusable. If I touch the metal parts on the guitar it goes off. If tremelo effect is turned up it's even louder. Now, you might be thinking, this sounds like a guitar ground issue. Here's what I've done so far:

-Tried different cables
-tried a different amp, was still there but not as loud (mesa express 5:50)
-brought my guitar to music shop and tried the same model amp..cranked up tremelo and volume and was silent or very acceptable.
-tried using power conditioner
-tested ground in outlet with circuit tester, outlet is grounded.
-tightened ground connections at breaker panel.

Only thing that I can think might be contributing is the house is older, built in 1957 and I have identified 3 outlets that have 3 prong receptacles but tested as not grounded. When I removed the outlet cover I verified there is no ground wire but I don't really use those outlets for anything so hasn't occurred to me to do anything.

Any ideas?

 

[fitz]

Have you confirmed it's not a guitar ground with a meter, or just the same amp at a music shop?
See if you have continuity between the strings and the jack sleeve on the guitar.

 

[Pete Farrington]

If I touch the metal parts on the guitar it goes off

That seems normal, and is why the strings and all external metal bits are connected to socket screen / circuit common.

tested ground in outlet with circuit tester, outlet is grounded.

Most basic testers can’t differentiate between neutral and earth.

 

[william vogel]

If by removing the receptacle covers you see only two conductors, it means the receptacle isn’t grounded. The panel cover (where the breakers or fuses) needs to be inspected. If there’s truly only two conductor wire run then your home receptacles aren’t grounded. This can lead to a lot of issues.

 

[Sly Fox]

I brought my guitar to the store to try the same model amp. I can test continuity with the guitar but what I heard at the store was silent and the volume was cranked.

 

[Sly Fox]

That seems normal, and is why the strings and all external metal bits are connected to socket screen / circuit common.


Most basic testers can’t differentiate between neutral and earth.

I did test the circuit and open the cover to see a ground wire. There were other receptacles i dont use for music that I know arent grounded, 3 anyways.

 

[Dogs of Doom]

In my house, built in '42, it was originally wired positive/neutral - no ground.

When I was working construction, just starting as a teenager, my boss told me to check the receptacle box. Usually they are grounded, & they used pipe & all boxes are connected together to ground that way. So, when it came time, here, I tested the boxes & sure enough, they are grounded, so I hook up all the ground to the box. Put a self tapping screw into the rear of the box, add a green wire to bridge the box & the ground on the receptacle, & you should be good. Just get a receptacle tester. If it tests good, you're good to go...

 

[aikiguy]

I've been in situations where room lighting has caused equipment buzzing... Are you playing near a flourescent light or something else than can turned off? It seems to me that if it were in fact a wiring problem, you would expeirence problems everywhere you've plugged, which if I'm reading thos correctly, you're not having this experience.

 

[Sly Fox]

I've been in situations where room lighting has caused equipment buzzing... Are you playing near a flourescent light or something else than can turned off? It seems to me that if it were in fact a wiring problem, you would expeirence problems everywhere you've plugged, which if I'm reading thos correctly, you're not having this experience.

I tried playing with the light switch on and off and made no difference. Many of the rooms had ugly ceiling fans that I replaced with light fixture only and if I remember correctly, there was wire I just capped off with one of those electrical twist on caps that went to the box unit part of the fan. Not sure if that tidbit is helpful but maybe the more details I can provide maybe something will make sense.

Interesting enough, I have a bankers lamp on my desk and when the buzzing is happening it does reduce when I touch the metal part of the lamp, even with the lamp off (but only if its plugged into the wall). This with my extensive physics and electrical knowledge makes me think it is a residential grounding issue lol

 

[aikiguy]

I tried playing with the light switch on and off and made no difference. Many of the rooms had ugly ceiling fans that I replaced with light fixture only and if I remember correctly, there was wire I just capped off with one of those electrical twist on caps that went to the box unit part of the fan. Not sure if that tidbit is helpful but maybe the more details I can provide maybe something will make sense.

Interesting enough, I have a bankers lamp on my desk and when the buzzing is happening it does reduce when I touch the metal part of the lamp, even with the lamp off (but only if its plugged into the wall). This with my extensive physics and electrical knowledge makes me think it is a residential grounding issue lol

Out of curiosity, have you tried to move them amp to another room and see if the problem still exists?

These ground issues can be a nightmare to nail down...

 

[fitz]

I can test continuity with the guitar but

.

 

[South Park]

the guitar bridge strings and turners have to be grounded to the center tap on the main power transformer,you should have a wire from the guitar jack to the bridge that grounds the guitar to the amp.when you touch the strings you become the ground and the noice stops

 

[zachman]

I'd start with presuming it's a ground conflict between your amp and your pedals.

 

[mickeydg5]

Playing a gibson es through vox ac15 and have an intrusive buzzing most noticable when playing clean. If I load up the rat pedal and play high gain some hum and hiss when not playing is acceptable but on clean it makes the amp totally unusable. If I touch the metal parts on the guitar it goes off. If tremelo effect is turned up it's even louder. Now, you might be thinking, this sounds like a guitar ground issue. Here's what I've done so far:

-Tried different cables
-tried a different amp, was still there but not as loud (mesa express 5:50)
-brought my guitar to music shop and tried the same model amp..cranked up tremelo and volume and was silent or very acceptable.
-tried using power conditioner
-tested ground in outlet with circuit tester, outlet is grounded.
-tightened ground connections at breaker panel.

Only thing that I can think might be contributing is the house is older, built in 1957 and I have identified 3 outlets that have 3 prong receptacles but tested as not grounded. When I removed the outlet cover I verified there is no ground wire but I don't really use those outlets for anything so hasn't occurred to me to do anything.

Any ideas?

When the guitar, in clean playing mode, is unplugged from the cord attached to amplifier input and the cord is dropped to the floor, is there still buzz from the amplifier?

And when playing clean and there is noise, is there still noise when you stop playing and not touching the guitar?

 

[XTRXTR]

 

[Sly Fox]

I'd start with presuming it's a ground conflict between your amp and your pedals.

While trying to isolate the issue I have been plugging straight into the amp, no pedals.

 

[zachman]

While trying to isolate the issue I have been plugging straight into the amp, no pedals.

Test your cables. If you have a fan near your amp, move it. If you have dimmer switches on the walls (that's a likely culprit) Turn them all the way off or on, not in between. It's possible you have lame wiring in the house and you may have an appliance on the same circuit as your amp, causing the problem.

If you're using an extension cord from the wall to your amp, the ground may be faulty. Have you tested your speaker cable?

I went back and re-read some of your replies, and I'd bet it's dirty power at your house, due to the age of the home, as described. Have an electrician test the ground and update your outlets

Best of luck

 

[Sly Fox]

I powered the amp on and started flicking the light switch/dimmer in adjacent living room and then the kitchen light/dimmer. That's what the problem was! The light in the kitchen is on all the time pretty much and the dimmer was set in probably the worst position for humming. Problem solved!

 

[MilosP]

Playing a gibson es through vox ac15 and have an intrusive buzzing most noticable when playing clean. If I load up the rat pedal and play high gain some hum and hiss when not playing is acceptable but on clean it makes the amp totally unusable. If I touch the metal parts on the guitar it goes off. If tremelo effect is turned up it's even louder. Now, you might be thinking, this sounds like a guitar ground issue. Here's what I've done so far:

-Tried different cables
-tried a different amp, was still there but not as loud (mesa express 5:50)
-brought my guitar to music shop and tried the same model amp..cranked up tremelo and volume and was silent or very acceptable.
-tried using power conditioner
-tested ground in outlet with circuit tester, outlet is grounded.
-tightened ground connections at breaker panel.

Only thing that I can think might be contributing is the house is older, built in 1957 and I have identified 3 outlets that have 3 prong receptacles but tested as not grounded. When I removed the outlet cover I verified there is no ground wire but I don't really use those outlets for anything so hasn't occurred to me to do anything.

Any ideas?

I've had the same experience with my Fender Player Plus Strat with Noiseless Pickups running through a Marshall JVM 205c. After setting up my music room in a different room of my house I started getting that annoying buzz/hiss that had not been happening before the relocation. My Band's Sound Engineer came over and suggested that it was electro magnetic interference being generated by either our roof top solar panels or my desk top computer monitor. Sure enough, at night when the solar panels are not active, the problem disappears. I've experimented with moving the amp to different parts of the room as far away from the solar panels and computer monitor as possible and, although it doesn't remove the buzz/hiss totally during daylight hours, it does make a considerable difference. If you haven't done this already, maybe try different locations to see if this reduces the noise.

 

[Dan Sing]

Adding my few cents:

All electric stuff that is connected to the electric circuit in front of our music stuff will influence the music-signal. The fridge starts? If it is connected in front of the music stuff, chances are great we'll hear that. Our partner uses the power drill? We'll probably hear a whistling noise. Something is defect - like the switch/dimmer of Sly Fox's kitchen light -? We'll hear it.

The best way to avoid these influences from our own household is to gift to our music-installation an own circuit (with +, - & ground: 3 cables !!!) and it has to be the first circuit after the main-fuse (!!!!!).

Connect there the ground-cable well to the ground-bar which should be in the near of the mainfuse, at least the cable to it.

And then connect nothing else to that circuit than the music-stuff, even not a lamp.