Weird buzzing behavior - pots/wiring

[abbnyc]

I set up in a new space, and I'm getting an irritating buzzing from my Eastman T185. I've unplugged everything else electronic in the area, turned off lights, etc, and none of that made a difference. Initially I assumed it was my amp, but it goes away when I unplug the cable, so it's definitely in the signal itself.

I noticed some odd behavior, though. My volume pots are set around 80%, and the buzz goes away below maybe 40%. At 100% the noise changes in character - tightens up and gets more treble. This happens identically on the bridge & neck pickups. But in the center position the noise gets way quieter.

Does anyone with a better understanding of wiring than me know what this suggests about the cause?

[wyndham]

Are you sure it's a problem with your guitar and amp? The fact that you're in a 'new space' suggests it may be related to issues in that space. Can you try your gear in another place just to see if that's the problem?

[pingu]

yes good advice there also
try different leads ....
and a different amp ....

[abbnyc]

Are you sure it's a problem with your guitar and amp? The fact that you're in a 'new space' suggests it may be related to issues in that space. Can you try your gear in another place just to see if that's the problem?

I'm sure it's related to the space. Just given the odd way that the pickups/pots were producing/responding to the noise makes me wonder if something about the wiring or pickups themselves could be exaggerating or allowing the interference.

I can try it in another room, but since the noise didn't respond to turning off all the lights and unplugging everything else that uses power in the room, I suspect it's something like the wifi router or the refrigerator (both on another floor), so another room might not change much. I'll give it a shot tomorrow PM, though, can't hurt to try.

[abbnyc]

try different leads ....
and a different amp ....

Unfortunately this is my only amp, but I can try another cable easily enough. Not likely to be an amp problem, anyway, since it goes away when I unplug the cable from the amp.

[sgosnell]

Lots of things can cause interference. Computers, lights, phones, wifi routers, etc. Sometimes it's the wiring in the walls. Moving the guitar and amp around can sometimes change it. My first inclination would be to move the guitar around, and then the amp.

[John A.]

So the problem arose when you moved the same amp, guitar, and cable to a new space? Unless one of the three got damaged in the the move, the explanation likely lies in the differences between the old and new spaces. Look for light dimmers, fluorescent neon or LED lighting, nearby heat/ac/ventilation equipment, refrigerators, elevators, anything nearby (doesn't have to be in the same room; could be next door) that puts out RF noise. In my apartment, the worst offenders are halogen track lighting connected to a dimmer and the building's elevator (which is next to my apartment).

John

[Cunamara]

John is spot on in that the source of the problem may not be in that room but may be in a neighboring space.


In my house, which admittedly was built in 1908 and has a mix of modern and not so modern wiring, I get a ~120 Hz buzz that occurs in the evening but not during the day, even with all the room lights, etc., turned off. I have yet to figure out the source of this noise. It seems to be something that affects the wiring in my signal chain rather than the pickups, since it occurs with both humbucker and single coil pickups.

Dimmer switches are notorious as are of course fluorescent lights. I have also found that timers for lights are problematical.

[Mark M.]

I have a similar issue with certain guitars when I play them downstairs in my practice room. I assumed it was the lights and have just been living with it. The wireless router is on another floor on the other side of the house, but the refrigerator is right above me. Interesting.

[rpjazzguitar]

I'd suggest turning off your cell phone.

It seems far fetched, but I read someplace that the output of the phone does depend on the proximity to the cell tower, or something.

Anyway, turning it off is easy enough.

[Cunamara]

Having my cell phone or iPad close to the pickup causes buzz.

[sgosnell]

If the noise only occurs at night, do you have a security light, or something else, that comes on at dark? Some older security lights can create a lot of interference.

[Cunamara]

If the noise only occurs at night, do you have a security light, or something else, that comes on at dark? Some older security lights can create a lot of interference.

There has to be something, I just haven't been able to figure it out. We don't have an automatic security light on our house, but the next-door neighbors do and I have thought about that as a possibility. I am wondering about the interference actually being on the powerline rather than radio frequency interference.

[KirkP]

Try using your pickup’s coil as a direction-finder. When you hear the buzz, try rotating your guitar at various angles, both azimuth and elevation. If you find an angle that nulls the buzz, the axis of your pickup coil is pointing toward the source of the buzz. Note that the source may be either in front of or behind your guitar.



Then bring your rig into a couple of other parts of the house and go through the same process. Try to discern where all the null axes intersect. This point might be in your house, a neighbor’s house, or maybe a power pole outside.

I must admit I’ve never tried this, but I get a buzz when my dimmers aren’t at 100%, so I’ll use the process sometime to confirm it works. It should, as RF direction finding is about as old as radio technology.

The assumption here is that you have a single point source at a distance. If the source is very close, if it’s distributed (such as from a long power line), or if it moves around with you (e.g., something in your amp) it probably won’t work. If you suspect your amp is the source, you might instead try moving the guitar various distances from the amp. If it’s loudest when you are closest to the amp, that’s probably the source.

I’m just shooting from the hip here. If you try it please report your results.