High “whistling” noise from my guitar/bass amplifiers in my home recording facility

Bad Disciple

New member
I'm afraid a serious problem has come to my home recording facility. It's a simple personal setting in my garage which I've transformed as a music space. Two computers (one laptop), two sound interfaces TC Twin Impact, a small 12 channels mixing table, a hi-fi system, keyboard, 4 different guitar/bass tube amplifiers, one digital modeled amp, effect units and some small gear around. I record "pilot" versions of music pieces, so not aiming to crystal high end quality, but still decent. And most of all acceptably noiseless. But here a problem appeared. Since few months I noticed a high "whistling" noise in my system when I plug any of my amplifiers with a guitar and (also the same in very high volume when my desktop computer is switched on). I spent quite few hours to test by excluding one by one different units. I also tested an amp with a guitar on other floors of my house and it has that high "whistling" noise everywhere. My house is relatively a new construction and I've asked the builder to put good ground and four different main sockets in my music room. That's really frustrating, as I'm unable to continue recording anymore, the noise is always recorded. I tried using a DI box, with no result at all. The mind blowing thing is that before I had no such a problem! I listen to past recordings and they are almost "crystal" clear! I'm heavily puzzled what could have happened and how should I go out of that situation! I've read some comments in the forums but they don't cover my problem.

I've thought about the only thing added in the house I can see were LEDs almost everywhere in the house. But the noise occurs in day time when no LEDs are on and in night time the problem is not bigger. For the rest, no fluorescent lights, desktop and laptop switched off, no phone chargers connected, no cordless phones (never!), no RF devise, no WiFI (we use "powerline" for the Internet but I unplugged all the adapters and no change). It's mind blowing...
*:-/ confused
Any ideas or suggestions?
 
Assumption: you have the problem in the amplifiers and in the computers (to a lesser degree) without amplifiers on. (Is that correct?)
Whistling would indicate 8k-12k somewhere? can you record a bit of it and run spectrum analysis to find the approximate frequency.
Guessing the problem is probably in the ground circuit of the house. Any new appliances in the home that are on constant? Hard to imagine what that could be... New neighbors? New meter from the power company?
Test the GFCIs in your house and make sure they all test and reset.
Man, I don't know. Probably a job for an electrician (which I've done a bit of help with, but I'm certainly NOT).
 
Assumption: you have the problem in the amplifiers and in the computers (to a lesser degree) without amplifiers on. (Is that correct?)
Whistling would indicate 8k-12k somewhere? can you record a bit of it and run spectrum analysis to find the approximate frequency.
Guessing the problem is probably in the ground circuit of the house. Any new appliances in the home that are on constant? Hard to imagine what that could be... New neighbors? New meter from the power company?
Test the GFCIs in your house and make sure they all test and reset.
Man, I don't know. Probably a job for an electrician (which I've done a bit of help with, but I'm certainly NOT).

The noise is produced directly from any of my three tube amps when plugging a single coil (a Strat w/ NOISELESS N3 pickups!) or humbucker guitars and even with just a cable plugged!! It whistles, no other hum noise! I tested on the other two floors of my house, it whistles everywhere. No constant appliances... The house is not old (15y.) and I asked the builder for a good ground mentioning I'm a recording musician! I tried with everything switched off and adding, but nothing showed to add or stop the "whistling". I'm not sure if I can measure the frequency (I'm a musician and an amateur studio guy indeed), but I can record it and post a snapshot if that's useful. Yes, I have new neighbors (a couple with a very displeasing behavior!) and I'm afraid they might have installed some units transmitting frequencies... So I start thinking of a kind of a simple Faraday cage... Or... I'll first borrow from a friend and test a wireless guitar system... Really no good picture...
 
What kind of lighting do you have throughout the house?
Many of the energy efficient lighting solutions are total shit for audio...they can induce all kinds of noise into your gear.

Yes, there are LEDs everywhere in the house (and no fluorescents or halogfenes), but the noise "whistles" in daytime when no LED lights are ON.
 
I've got LEDs everywhere in my house, too. No whistles...then again, all I've got for amps is my Vox AC15 and my Yamaha B100 (both have tubes...)
My house is around the same time frame ('99)
I've got one of those electric fences for my dog, but it doesn't show up. Sometimes certain people's cell phones cause disruption when they're getting data and the Vox is on, but that's not a whistle...and it only seems to happen with LG phones. None of the wife's Galaxy's do anything untoward.
Reason I asked about neighbors is obvious. Problem started soon after the neighbors moved in, it's probably something they've done. Any way to ask nicely if they keep their router or some other transmit/receive device on 24/7?

Okay, rather than see the sound, let's give it a listen. Can you post a WAV of it and let us hear?

Does it whistle when there is no cable plugged in the amp? I think you answered that, but I want to be certain and clear.
 
It does sound like an RFI problem and an external one at that. My first thought was a USB converter artefact but if it comes through with just an amp and guitar running, not that.

PLEASE post a clip! 10 seconds as a the best quality MP3 will be fine (I can then drop that straight into Samplitude and convert it to .wav 16 bit for Right Mark Annylzer. Please ATTACH the clip, save me having to record it.

Dave.
 
Ok guys, you are fantastic with wanting to help me! Here a wav file. Pls, let me recapitulate. The "whistling" is present EVERYWHERE in my house, even in the mansarde under the roof. There is no other noise like hum or so, just "whistling". The "whistle" is present with humbuckers too and with both my three tube amps. The most shocking: it appears even just with the cable plugged, without any guitar!
So in the wave file I recorded my Strat with (supposed to be) Noiseless N3 PUs and I change the 5 position switch from Bridge to Neck. The Bridge PU seems to have less "whistling". It also has a "push-push" switch putting the PUs in a serial connection where the "whistling" is louder. Strangely, when I play few chords, the "whistle" between them is lower and not recorded, but I heard it when playing.
Another info, I asked my left neighbor (who are a retired couple so no much high-tech) to unplug his wireless home phone, but the "whistling" is still there. So not that.
And no, it doesn't "whistle" from the amp itself, only after plugging the cable and the rest described.
That's all about the mess. That stops me from work and it drives me mad as you can imagine. Any suggestion would be highly useful before I call an electrician.
Thanks a lot!
 

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Wow - I must admin that wasn't what I expected at all. You have a 2.5K tone, with a harmonic at 5K, then another 2.5K up. When you plug the guitar in and hear the tones, does rotating the guitar by you spinning around change the level of the tone? If you get nulls, where the signal has a definite dip, then the offending source will be at 90 degrees to the neck, as in straight ahead, or immediately behind you. If there really is a dip you can detect, you could then move the amp to another room, and repeat the test, and hopefully the dip will be in a different direction. Where these two paths cross is your interference source. If there really isn't much of a null, then there is a chance that like your internet system (horrible devices, to be perfectly honest) the interference is spreading through your house wiring. If you know where the cable run, approach one of the runs and see if it's louder. I did have something similar a few years back - a faulty baby monitor, that used the mains wiring to allow you to listen in the downstairs rooms. It was unstable and injecting harmonics into the wiring, which despite them saying they don't, do spread through the street wiring into your house if they are physically close. You might be able to confirm the mains wiring is carrying it if you can plug your guitar into a battery recorder, or maybe even a laptop. If the guitar and recorder are totally isolated from the mains, and you can still hear the interference, then it is RF interference - and the offending device is probably faulty, BUT, your system should ignore it. For RF interference, the RF has to be demodulated by something - and this shouldn't really happen. It can (and sometimes does) but is usually a totally different second fault - and easily proven by swapping the guitar.

Now comes the tricky part - and unless you are competent, you MUST NOT do this.

We always tell people that disconnecting earths to equipment is stupid, dangerous and potentially lethal. We acuse anyone who says they do this of being totally mad - and they usually are.

I must make it clear that anyone doing this MUST know what they are doing and take proper precautions.

So from here - please take care. Set the amp up with the guitar so that it is producing the noise without you touching it, or touching anything else that could possibly conduct electricity. I'm seeing the amp in the centre of the room, with the guitar perhaps leaning on it, safely.

It's whistling away. Switch the power off at the mains plug, and pull it out. If you know what you are doing and are comfortable with plug wiring, open the plug, disconnect the green and yellow conductor, and bring it outside the plug, over the cable grip. Screw up the plug again. the bare end sticking out of the entry, and wrap a bit of tape around it to prevent it moving. With the mains switch off, plug it in again and do NOT touch the amp or guitar. Once it is working you have two possibilities.
1. You still have noise - the interference is RF interference and strong enough to be demodulated by even a poor connection in the jack, or even by dissimilar metals in the jack lead.
2. The noise is gone - then it is mains borne - and being distributed on the earth.

Reconnect the earth wire before you do anything else.

If the interference is on the earth, then this probably signifies the earth is compromised in some way, and you need a proper electrician to come in and check the bonding.

Another guess, but one that drives radio hams mad is remote metering - your electricity and gas meters broadcast their readings so somebody outside can read them. This interference often spread for a long way, but usually has a data content - so warbles, but could be your problem.

First job - see if the single core strategy pickups can lead you in the right direction.

If you can avoid lifting the ground, please do. I've been dealing with electricity for a long time, and can take appropriate safety measures. If you can't, don't do it - maybe you have a friendly electrician who can read this and do it for you?


Your problem is a nasty one for sure, and tracking it down will be pretty tough. Sadly, OFCOM won't be bothered about interference to a guitar. Or at least, it will be bottom of the pile, priority wise.

Let us know how you get on.

My bets are in this order.
1st Baby alarm gone faulty next door
2nd a cheap, faulty switch mode power supply, plugged in 24/7 that is oscillating.
3rd Remote monitoring of electric/gas meter.
 
Around 2.45kHz with two octaves (4.9 and 9.8). Not GHz, which would be a phone.
Lower than I'd expected. Not sure what would even sound in that range as Radio Frequency Interference...there was a device we used to find underground cables that ran a frequency through the line and you could pick it up with the receiver. Guy I worked with called it a "Gopher", but I can't find any reference to anything like it by googling...still. If the power company left something like that hooked up to your outside lines, it could be the source. What you heard through the headset of the "Gopher" was an audible tone about that frequency.

Ahh. missed that. It's not an octave at 9.8, it's at 7.35...odd. Summing frequencies vs octaves may mean something to someone with a better electrical background than I.
 
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Hail back cool fellas! Thanks for your so valuable support !
So, no baby alarm system (a house alarm yes but that's present already 15 years while the problem is only recent), no 24/7 systems, no monitoring electricity/gaz meters. I've got WiFi Internet but it never interfered before. And we also use now 'powerline' adapters passing through the power circuit of the whole house, but again, I disconnected them all and the "whistling" was always there.
Now, YES, when I rotate and spin around with my guitar, there is a spot where the "whistling" is almost null. So, I'll try with that crossing two paths from different positions.

But until now I made these three tests:
1. From the house service panel I totally switched off the power of all the upper house floors (separated from the ground floor which is my music place). Whistling still present. Then in the service panel of the ground floor I switched off all the breakers, leaving only one (initially meant for kitchen appliances, so surely well grounded, even if I asked the same for all the circuits when building the house 15 years ago). In that socket I plugged my amp and cable and guitar, and the "whistle" is still there. So I guess the godforbidden reason must be an independent radiation !
2. I borrowed from a friend a wireless system w/ transmitter on the guitar and receiver on the amp. The "whistling" still present.
3. I imagined that a simple Farday cage might be a solution but it would be a big mess. Then... I thought to make a "Faraday cage" to a single cable. So I took a garden mesh made of fine metal wire and rolled it as a "tube" and then I placed a short cable in it, and connected a wire to the ground of one receptacle. Then... wonder, the "whistling" was gone!! So I think now it's sure that it is a radiation coming from some external source. Then my thoughts go to asking what kind of such metal wire "tubes" exist so I ground them, run my cables through them and continue working at least until I find the real reason and fix it (or maybe not?)?
 
Do you live under a telephone pole?

If you have the money, purchase an EMF meter. I like the Trifield. It might track down the cause, and they're good to let know you what in your house to avoid and/or be at safe distance.
 
Seems to be at about 2.4 kHz and its harmonics.

It does seem to be an RF carrier of some kind the screening experiment has given me an idea. Can you solder?

You need some "balanced" i.e. 2 core mic cable. One end you wire as normal, screen and "cold" black say, wire to screen of jack. Other end do not connect the screen braid but tape it, better heat sleeve it back and just make the screen connection via the cold wire.

This ensures that no RF current pass along the shield and if current cannot flow it cannot induce a signal in an adjacent wire (yeah, I know! Bit of a theoretical grasping at straws but the technique often works for RFI and is cheap)

Another cheap try is some snap on ferrites (Maplin if you are UK. FKs if you are elsewhere!)

Dave.
 

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Seems to be at about 2.4 kHz and its harmonics.

It does seem to be an RF carrier of some kind the screening experiment has given me an idea. Can you solder?

You need some "balanced" i.e. 2 core mic cable. One end you wire as normal, screen and "cold" black say, wire to screen of jack. Other end do not connect the screen braid but tape it, better heat sleeve it back and just make the screen connection via the cold wire.

This ensures that no RF current pass along the shield and if current cannot flow it cannot induce a signal in an adjacent wire (yeah, I know! Bit of a theoretical grasping at straws but the technique often works for RFI and is cheap)

Another cheap try is some snap on ferrites (Maplin if you are UK. FKs if you are elsewhere!)

Dave.

Thanks a lot for that advice. I think I read something about it somewhere. Don't they call it a "one-ended shield bonding"?

Yes I can solder, since all the past I make my cables by my own with a good quality cables and plugs. So, let me make it clear for me: if taking example from the XLR connections, the pin 1 shield bride and the "cold" pin 3 (blue or black) must go bonded together to the plug screen at the one end. Then at the other end they must be split with only the "cold" bonded to the plug screen while the shield bride cut and isolated. Right? Of course, the active pin 2 (red) wire goes bonded to the active pins at both ends.

BTY, I didn't get it about the other way with ferrites. (I'm just a recording musician with some electric knowledge from experience). :-)
 
Ferrite Clip On HEM3012 | Maplin

Them's ^ the jobbies. You wind a guitar cable around one or more and snap them closed. Yes, you have the cable idea, no shield connection one end but "return" completed by the shielded cold wire.

"No doubt" about the guitar screening, does that mean you are sure?

Dave.
 
Ferrite Clip On HEM3012 | Maplin

Them's ^ the jobbies. You wind a guitar cable around one or more and snap them closed. Yes, you have the cable idea, no shield connection one end but "return" completed by the shielded cold wire.

"No doubt" about the guitar screening, does that mean you are sure?

Dave.

OK, thanks! Never have heard about those ferrites! I'll give them a try if the first philosophy doesn't work so well. Or combine the two methods? Tomorrow I'll do the first test, cause I already did one similar combination today but with a normal cable, not a balanced one (still it diminished significantly the "wistle"!)

I use three guitars, two Strats (a traditional older on and a new one with noiseless N3 PUs) and one Parker Fly with HBs and I never had that problem before few months. So I assume they are properly screened. And the "whistling" problem is relatively "recent".

BTY, now that I think, last year the electricity company came and dug in the whole street to make some new underground installations... Couldn't that be the godforbidden reason for my problem??
 
I doubt the electric company's work is the problem.
Mind you! They are starting to push REALLY hard for people to have "smart meters" and by definition these send RF down the mains but I assume it is a burst data stream? They would not have a CW running.

A recent TV programme showed WE are being shafted by these meters! WE pay for them but the utility Cos and shareholders reap the profits. Meter readers lose their jobs. The utility companies can change your tariff at a click of a mouse and there are switches in the meters so if you bitch too much they can turn you off!

Dave.
 
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