Years of unsolvable (RF?) noise stopping everything.

drivepilot

New member
Hey all. Would love some help or troubleshooting advice as I don't know what else to do any more.

I've been doing studio stuff fairly professionally for 20+ years and never ran into anything like this before. It's really wreaking havoc on my motivation to record, as it's impossible most of the time.

I have a static / crackling noise, in everything, that has prevented me from recording and I've tried everything I can think. It's persistent, but will suddenly vanish for some period of time, maybe 2 minutes, maybe 30 minutes, I think even maybe days at some points in the past, but inevitably returns. When it disappears, it's sudden and random and very noticeable (SEE VIDEOS). It sounds like a mix of radio static and someone rubbing their thumb on a mic. I don't have ground loop 60hz hum issues or buzzing issues when properly plugged in/normal use.

I'm in a single home that isn't particularly old, maybe 70s I think. Its every amp I have or tried (loudly), in amp sims when I DI into my UA Apollo Twin (loudly), it's in monitors (a bit more subtly). I was doing mostly ITB stuff for the first few years at this house so I didn't notice until I got more into analog/outboard/amps again. Its loud enough it really interferes in clean recording or how gates open/close. Any gain and it's pretty unusable. It will be gone sometimes and I have a perfect noise floor when this happens. As soon as I get in a groove it'll strike again. I feel like I'm being haunted.

What I have done:
• Furman PL PLUS C, as well as my original cheaper Furman, as well as EBTech HumX I use to remove a minor ground issue from a sub
• Cables — I have all pretty high grade cables, and have tried all Mogami, Caulfields, etc, direct into amp or interface and get this interference.
• Ferrite wraps
• Shut off/unplug everything in house, kill all breakers except one wall with just amp, and still have the interference
• Tested wall outlets with one of those testers that says if things are grounded right, all good
• Have tried 5 amps, 7 guitars, all share the problem, as well as my studio monitors (to a lesser degree)
• Rolling off volume pot on guitar does kill signal and noise together, so not just amp tube or something crackling, which wouldn't make sense anyway
• Bought a weird RF signal handheld visualizer thing, but haven't sat long enough and waited for static to disappear while watching to see if I see anything correlating
• Just bought a battery powered little amp that hasn't arrived to see if I get the interference when not connected to the mains whatsoever
• Asked friends online, none have had anything like this

I've not had problems in other houses, with cheaper gear, lesser cables. I don't think I've got power lines around, and I'm not sure of any radio station broadcasting in my area (97078). I was almost convinced a neighbour had a weird RF broadcast device to torture me for being too loud.

Here are a couple videos that show the problem

This one is pretty good since it shows the sound, and then suddenly stopping. The background hum is fine since it's coming from an ungrounded unplugged cable during this test


Here's another through a different amp on a different day, and its throughout the whole clip as kind of that rubbing-on-a-mic sound. I've got a guitar plugged in but idle sitting on a chair, and the amp turned way up, so some background hum-type noise is appropriate here too.


Please help if you have any thoughts! :(

Thanks so much for your time
Ellis
 

rob aylestone

Well-known member
Some of that just sounds like a high gain amp with a single core pickup guitar turned up and leaning against the wall. When you play, how far below the notes is that hum? Those crackles sound like some kind of arcing. This can propagate through the house wiring, like those network systems that send data superimposed on your house wiring. So some device with a loose live/line screw in a plug or socket. Anywhere in your house. The arcing just follows the cable.
if the guitar has the volume controls all on off, I.e.silent, does that noise vanish? If you hold the guitar vertically and slowly rotate it through 360 degrees so it passes through all points of the compass, does the hum change in type or tone? Do all guitars do it? Does another guitar do exactly the same?
 

drivepilot

New member
Some of that just sounds like a high gain amp with a single core pickup guitar turned up and leaning against the wall. When you play, how far below the notes is that hum? Those crackles sound like some kind of arcing. This can propagate through the house wiring, like those network systems that send data superimposed on your house wiring. So some device with a loose live/line screw in a plug or socket. Anywhere in your house. The arcing just follows the cable.
if the guitar has the volume controls all on off, I.e.silent, does that noise vanish? If you hold the guitar vertically and slowly rotate it through 360 degrees so it passes through all points of the compass, does the hum change in type or tone? Do all guitars do it? Does another guitar do exactly the same?
So yeah, The crackling/static noise is the only offending noise, the hum from the coil is only there because it's cranked up and never a problem. Both of these vids were from trying to pull the noise out and capture it clearly since it's intermittent. Even when amps are down, it's very obvious in normal playing when it's there, and was never a problem with the same gear in any of my other studio spaces or homes. This static is still there in humbuckers as well fwiw when the it's around.

• Yes, it disappears with rolling off the volume. I also do get this static at the same time in my studio monitors.
• No rotation, movement or change in room, or anything changes the tone of the static or amount of its presence when it's around.
• Every guitar (I have 7 w different p/u styles) and all of them and every amp is affected when this static is around. DI to interface as well is completely unusable and I've been tracking DI for years and years normally.

The static/crackling will suddenly disappear and then suddenly reappear any random amount of time later. Doesn't appear to correlated to any device a neighbor might turn on or off. It's also a problem more than it isn't— probably 90%+ of the time— so doesn't appear to be like a hair dryer or something a neighbour might run.
I did power off all breakers, save for one wall, and still have the problem so not sure if that interesects with your theory about a screw in a socket arcing? Though not 100% what you meant. Have a battery powered little amp coming tomorrow to see if I get interference through the air or if the noise is strictly from the mains.
 
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rob aylestone

Well-known member
Good tactics. You’ve sort of proved a few things. Rotating a guitar is very directional. If it was radio frequency noise, as in direct interference, rotation would change it. This suggests noise via the wiring. I know you’ve tried the breakers, but have you tried plugging it into the power in a room served by a different breaker and switching off the breaker that supplied the music room? That is your final proof as the only breaker you cannot turn off is the one that supplies the amp.

this will either silence it, or not, crackle wise.

the bad news is that it is actually possible for an amp to produce this kind of noise internally - usually faulty or aged capacitors. A reasonably common fault and one reason why many people recon amps with new capacitors as step one in doing them up. Tubes can also crackle. Faulty and worn out tubes/valves can make most weird crackly noises. Swapping the amp for another will point the finger. Your process so far suggests the thing is knackered. British term, but quite suitable.
 

rob aylestone

Well-known member
Oh - I missed that. I must have read it wrong - I thought we'd tied it down to the amp. Apologies. Got to be an electrics problem. Swap the amp and see what happens.
 

drivepilot

New member
Thanks for all the thoughts. Definitely not the amp. It's every amp, & every situation involving unbalanced cables or pickups of any kind.

And importantly:

I bought a mini battery powered amp to test if the pollution is through mains/power -or- over the air, and it arrived today and unfortunately it seems like it's over the air. I get the exact same static even not connected to mains.

So definitely something completely in the air, which to me seems like literal worst case. As far as I understand now I need to get an AM radio and walk around and see if I can find where it's coming from? The weirdest part is that it will completely go away for minutes or hours or days, but it's probably there 95% of the time. I DO know that there is a guy who works on cars in his garage up the way and I will certainly be starting there first. The fact it goes away the way it does and is constant seems odd though. Im not around any power lines.

Thanks again for helping think through things. I'm honestly at the end of my wits and trying to work on music has become painful and depressing.
 

TalismanRich

Well-known member
This is a toughie! I was thinking about getting a good power filter, but your testing with a battery powered amp kills that idea. I thought about something like a bad mercury vapor lamp but that normally wouldn't be on 24/7. Is there a manufacturing site close by that works 24/7? Maybe some place that does something like robotic welding? Tracking down airborne interference can really be tough. Depending on the source, stopping it might be tougher, short of building a Faraday cage,
 

drivepilot

New member
The other weird thing is that it's usually there, but it will just drop quiet for some (usually small, not always) amount of time, but returns.

I'm in a residential neighbourhood for the most part. I'm a quarter mile line of sight to a funeral home, quarter mile to a dentist, and half mile to a High School and small shopping area. I don't think there's really anything else around. I think a guy does car repair up the street in his garage of old cars, but a welder doesn't make sense because it will be crackling at 4am and 95% of the time. Thinking about this made me think maybe the High School is broadcasting, but the on/off pattern doesn't make sense.

Thanks for thinking through this with me a little.
 

rob aylestone

Well-known member
I thought welders, but that wouldn’t be most of the time. Your next snag is detecting it. A good device is a monitor for hearing loops. Specially designed for electro-magnetic radiation. Or, a person who has a hearing aid fitted with a loop system receiver. Other useful and cheap kit would be a simple RF SDR dongle. Very cheap and free software. Then things like RF Explorers which the radio mic folk like to use. If the interference is coming from a distance, then it’s probably powerful too as distance follows the inverse square law, so noise coming into the home like this has to be powerful if it’s a distance, unless it’s got a direct connection. This means telephone, internet, power, even insulated gas and water in metal pipes. Another possible source would be the power system. You’ve turned off breakers inside the house which suggests your internal system is clean, but how does power enter? Underground, overhead? It’s very common now for supplies to have neutral and ground bonding, on the supply companies side of the wiring. It’s possible that this bonding may have failed and this is arcing, and would probably be load dependent in the neighbourhood. If you know what you are doing and have a voltmeter, put it across the neutral and ground connection at a 3 pin outlet. Ignore the live/line conductor. Neutral to earth could have a volt or two between the, if your property is large, but should be virtually nothing. Volts here is suspicious, and depending on the current, could be fizzing away in a dirty failed junction. Any noise here would propagate through the wiring even with breakers off as they usually just interrupt the live/line path.

That better amp could be very handy if you move it around, even outside. I assume it hums when connected to a guitar, rather than just hums happily with nothing connected. Your AM radio idea is a good one for tracking it down. I’m thinking more now of potential safety issues too. Clearly something is wrong here. If you track it down to the power company, they’ll investigate, but you need to get a bit of evidence together scientifically.
 

R D Smith

It's as good as it is, for as long as it lasts.
Turn off the main power disconnect by the electric company usage meter if you have a modern electrical service. If you have an older service like I do with no disconnect, you have to pull the meter. See if you still get the noise on your battery powered amp. Hopefully, it's something in your house.

Power line noise is fairly common and hard to track. Be aware that the noise can easily come in on the ground (big antenna) and that is not disconnected when the main breaker is turned off. Next step is take your AM radio and walk around the neighborhood and see if you can locate it. Don't be surprised if you can't, it could be far away.
 

Mickster

Well-known member
Geeez...tough one. Could be from your house power meter if it reports remotely.....or your water meter the same way. My solar panels report via cell technology but it uses a cheap power supply. It could even be a new car using RF tech to communicate between your key fob and the car itself. My wifes car checks to be sure the key fob is not in the car when it's not running....and also makes other checks with the fob. Keep in mind it could be any of these things in a home very near yours.

My guess is the same as others in that it's in the local neighborhood.

Best of luck and let us know if you ever solve it.

Mick
 

witzendoz

Senior Member
Back in the 1990’s my studio was across the road from a phone exchange, this caused tons of rf that was in fact transmitted through the actual mains into the house. The phone company sent techs and it was proved by running the guitar amps on a ups system that was unplugged from the mains. They also started the emergency generator at the phone exchange and took it off the mains which also fixed it. The solution was to get a large ish ups and use it on batteries when recording guitar.
i would look around the area to see if something is inducing RF.

the other thing to make sure of is to have a really good earth on the house, I even put down an earth stake and bonded it to the house earth.

cheers
 
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