Author Topic: Home recording studio - noise with guitar amps - who to call?  (Read 5894 times)

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Offline DaveNJTopic starter

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Re: Home recording studio - noise with guitar amps - who to call?
« Reply #25 on: November 20, 2022, 07:54:24 pm »
I haven’t. So, are you suggesting that I connect a separate wire from the shield of the guitar cable to the ground pin of the amps power plug?
 

Online ebastler

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Re: Home recording studio - noise with guitar amps - who to call?
« Reply #26 on: November 20, 2022, 08:02:17 pm »
I would go from a metal part on the guitar (the pickup cover, knobs or such -- you had shown them all to be connected) to an exposed metal part of the amp, e.g. the nut of the 1/4" jack on the amp.

This is essentially to double-check that the two 1/4" jacks, two plugs and the cord inbetween do actually provide a ground connection. You could also measure continuity between the two mentioned metal parts with your multimeter.
« Last Edit: November 20, 2022, 08:03:54 pm by ebastler »
 

Offline DaveNJTopic starter

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Re: Home recording studio - noise with guitar amps - who to call?
« Reply #27 on: November 20, 2022, 09:41:27 pm »
OK, I just ran a piece of 12 gauge wire from the input jack nut to the guitar (try the strings, volume pot, control plate) and there was no difference.
 

Online ebastler

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Re: Home recording studio - noise with guitar amps - who to call?
« Reply #28 on: November 20, 2022, 09:56:43 pm »
Hmm, then maybe the blanket was shielding the guitar in your video -- but the shielding only works when the blanket is grounded, by making contact with one of the grounded metal parts on the guitar?

You could check that by putting the blanket underneath the guitar with the blanket's non-conducting side facing up; it should have no effect then. But if you connect the ground wire from the amp to the blanket's conductive side, it should shield the noise (if this theory is correct).

Not sure what the conclusion would be if you can confirm this. Probably some strong electrical fields coming in from outside; but what would you do about them?

One more thought: Do you have a battery-operated amp handy, or can you borrow one? If the noise also shows up with a humbucker guitar and the battery-operated amp, you would have confirmed that it is not coming in via the mains but via radiated immissions.
 

Offline DaveNJTopic starter

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Re: Home recording studio - noise with guitar amps - who to call?
« Reply #29 on: November 20, 2022, 10:02:49 pm »
Yes! We actually did try that (blanket underneath but conductive side down)and it didn’t do anything.

I do have a battery powered amp, but I have to go get some batteries :-)
 

Online fourfathom

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Re: Home recording studio - noise with guitar amps - who to call?
« Reply #30 on: November 20, 2022, 10:38:58 pm »
Back to the magnetic fields, remember that a guitar pickup is *supposed* to convert magnetic fields to electrical signals.  Grounding, shielding, aren't going to fix that, nor should they.  Humbucker pickups (think Les Paul) are less sensitive to these external fields, but are not completely insensitive. Single-coil pickups (Strat, Telecaster, etc.) are particularly vulnerable.  Transformers, motors, some lighting, some wiring can generate these fields.  If the hum changes when you change the guitar orientation then this is not a grounding problem -- you are picking up these fields.  Perhaps there are additional sources of noise, but you do have to address the magnetic field problem.
We'll search out every place a sick, twisted, solitary misfit might run to! -- I'll start with Radio Shack.
 

Offline DaveNJTopic starter

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Re: Home recording studio - noise with guitar amps - who to call?
« Reply #31 on: November 20, 2022, 11:00:28 pm »
Agreed. Which brings me back to my topic title - are there any specialists I can work with to try to identify the source (in addition to the electric company)?
 

Online fourfathom

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Re: Home recording studio - noise with guitar amps - who to call?
« Reply #32 on: November 21, 2022, 12:35:42 am »
Agreed. Which brings me back to my topic title - are there any specialists I can work with to try to identify the source (in addition to the electric company)?
Sorry, I'm no expert and I don't know anybody who is.  Just speculating wildly, but you might try hooking a solenoid coil (or guitar pickup?) to a battery-powered headphone amp and walk around the area trying to locate the source(s).  A solenoid coil can have a fairly sharp null which might help in triangulating the offender.  If you can deal with this at the source that has to be way easier than paneling your basement in Mu-metal.
We'll search out every place a sick, twisted, solitary misfit might run to! -- I'll start with Radio Shack.
 

Online BrianHG

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Re: Home recording studio - noise with guitar amps - who to call?
« Reply #33 on: November 21, 2022, 01:06:47 am »
4. Power in my development is underground. but is fed from above ground wires about 0.2 mi from my house. There're above ground transformer boxes on my block or around the corner.

2. The loud buzzing and clicking only happens when a guitar with passive pickups is connected and the volume on the guitar turned up.

I previously suggested that you spin the guitar around and see if the noise changes.  Have you tried that?  This sounds like magnetic fields hitting the guitar pickup, rather than conducted electrical noise.

Yes, it does change when I rotate it but as you can see in the video, it‘s actually the worst when it’s flat on the floor.

I just reached out to my power company again to request that they assist with locating the source. I think it’s outside of my house, as well.

I am so sorry, but it looks like to me that you are to close to the transformers in your area as I had a similar problem at my old address.  (Even worse, with all power turned off at my old location, you could hear my ducts humming/vibrating during the coldest winter days.)  I do not know if there is much you can do other than metal shielding your entire room where you play your guitar, and even that may not work if your pickups are responding to a raw magnetic field.

I wonder if you should look into electric guitars with piezoelectric pickups.  They will probably be immune to magnetic fields, however, they might have a different sound characteristic.
« Last Edit: November 21, 2022, 01:10:20 am by BrianHG »
 

Offline DaveNJTopic starter

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Re: Home recording studio - noise with guitar amps - who to call?
« Reply #34 on: November 21, 2022, 01:36:05 am »
4. Power in my development is underground. but is fed from above ground wires about 0.2 mi from my house. There're above ground transformer boxes on my block or around the corner.

2. The loud buzzing and clicking only happens when a guitar with passive pickups is connected and the volume on the guitar turned up.

I previously suggested that you spin the guitar around and see if the noise changes.  Have you tried that?  This sounds like magnetic fields hitting the guitar pickup, rather than conducted electrical noise.

Yes, it does change when I rotate it but as you can see in the video, it‘s actually the worst when it’s flat on the floor.

I just reached out to my power company again to request that they assist with locating the source. I think it’s outside of my house, as well.

I am so sorry, but it looks like to me that you are to close to the transformers in your area as I had a similar problem at my old address.  (Even worse, with all power turned off at my old location, you could hear my ducts humming/vibrating during the coldest winter days.)  I do not know if there is much you can do other than metal shielding your entire room where you play your guitar, and even that may not work if your pickups are responding to a raw magnetic field.

I wonder if you should look into electric guitars with piezoelectric pickups.  They will probably be immune to magnetic fields, however, they might have a different sound characteristic.

It could be, but I’m holding onto hope. If you look at the video I posted from that other guitarist, his power company in Canada was able to address it. I’ve reached out to him asking for any detail he can provide.

Non-magnetic pickups certainly sound different - the EMGs I have in that one guitar are not susceptible to interference, but they aren’t regarded as “the best sounding”. Now, vintage guitars with old p90 pickups are some of the best sounding, but also the most susceptible.

I’ll definitely circle back if I find more details or a solution to close the loop. I really do appreciate you all looking over this and offering suggestion and insights.
 

Online BrianHG

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Re: Home recording studio - noise with guitar amps - who to call?
« Reply #35 on: November 21, 2022, 01:39:20 am »
Looking at my old location:



You can see that I lived 175 meters / 0.1 miles from the high tension power lines feeding part of the city of Montreal, supplying a population of 1.8 million people.  Worse, I was 500meters / 0.3 miles from the booster station at the bottom left.

Believe me when I say, all the really sensitive analog electronics I worked on has measurable interference on my oscilloscope.  My 75Hz 21inch studio grade CRT computer monitors would also vibrate the image like mad on some days unless I used a 60Hz, 90hz, or 120Hz video modes.  There is nothing the power company can do as the transformer station and power lines when heavily loaded will radiate out.  The field was strong enough to illuminate a white LEDs just by touching 1 side to a long metal beam part of my workbench table with the other wire contact held in my hand.
« Last Edit: November 21, 2022, 01:41:29 am by BrianHG »
 

Offline DrGeoff

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Re: Home recording studio - noise with guitar amps - who to call?
« Reply #36 on: November 21, 2022, 01:44:38 am »
Can you add a filter to the mains supply for the guitar amp?
A balanced EMI filter might be worth trying to eliminate conducted noise on the mains.
Was it really supposed to do that?
 

Online BrianHG

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Re: Home recording studio - noise with guitar amps - who to call?
« Reply #37 on: November 21, 2022, 01:45:00 am »
Can you add a filter to the mains supply for the guitar amp?
A balanced EMI filter might be worth trying to eliminate conducted noise on the mains.

Not a mains issue, read his post.

Non-magnetic pickups certainly sound different - the EMGs I have in that one guitar are not susceptible to interference, but they aren’t regarded as “the best sounding”. Now, vintage guitars with old p90 pickups are some of the best sounding, but also the most susceptible.

Your chances have diminished.

If it were mains interference, the amp's input and wiring would replicate the same 60hz hum on his EMG guitars as the magnetic coil guitars.  It is truly a magnetic field transmission like what I had at my old location where even computer monitor electron guns where being pushed in and out over-driving the deflection 'YOKE' due to the 60hz magnetic field.

Only 360 degree, below and above copper plate shielding might clean this up.
« Last Edit: November 21, 2022, 01:58:46 am by BrianHG »
 

Offline DaveNJTopic starter

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Re: Home recording studio - noise with guitar amps - who to call?
« Reply #38 on: November 21, 2022, 03:22:12 am »
Looking at my old location:



You can see that I lived 175 meters / 0.1 miles from the high tension power lines feeding part of the city of Montreal, supplying a population of 1.8 million people.  Worse, I was 500meters / 0.3 miles from the booster station at the bottom left.

Believe me when I say, all the really sensitive analog electronics I worked on has measurable interference on my oscilloscope.  My 75Hz 21inch studio grade CRT computer monitors would also vibrate the image like mad on some days unless I used a 60Hz, 90hz, or 120Hz video modes.  There is nothing the power company can do as the transformer station and power lines when heavily loaded will radiate out.  The field was strong enough to illuminate a white LEDs just by touching 1 side to a long metal beam part of my workbench table with the other wire contact held in my hand.


You know, looking at the image you posted, I may have misstated something - I’m not .2mi from high tension wires, I’m .2mi away from above ground, residential power lines. The towers are a good 10 miles or so away…

I’ll let you know what the power company says…
 

Online BrianHG

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Re: Home recording studio - noise with guitar amps - who to call?
« Reply #39 on: November 21, 2022, 07:46:55 am »
You know, looking at the image you posted, I may have misstated something - I’m not .2mi from high tension wires, I’m .2mi away from above ground, residential power lines. The towers are a good 10 miles or so away…

I’ll let you know what the power company says…
See what your power company can do.  You should not be having the problem I was having as those transformers in my attached image 0.3mi from my house power ~25% of a city.  I'm not talking about the tiny telephone pole style transformers which only power a few houses.  (I feel sorry for those houses whose back yards are just across the street from that booster station, within ~0.05miles.)

The only other thing I can think of is if somebody right next door, or withing the same building has some big ass machine with a huge AC motor or giant transformer running 24/7.
« Last Edit: November 21, 2022, 07:54:56 am by BrianHG »
 

Offline jonpaul

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Re: Home recording studio - noise with guitar amps - who to call?
« Reply #40 on: November 21, 2022, 01:38:10 pm »
See library of Jim Brown and Don Davis,  at SynAudCom, excellent papers and tips

https://www.prosoundtraining.com/

Jon
An Internet Dinosaur...
 
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Offline magic

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Re: Home recording studio - noise with guitar amps - who to call?
« Reply #41 on: November 21, 2022, 07:11:25 pm »
I have no experience fighting with low frequency magnetic fields, but people say that they are a bitch to block, basically requiring thick solid steel or stuff like that.

OTOH, the behavior you show is perfectly consistent with (perhaps unusually strong) electric field. These fields are stopped simply by surrounding the sensitive circuit with any reasonable conductor connected to the circuit's ground. It looks like something internally at the back of the guitar is receiving the noise. I guess that sticking a layer of aluminium foil to the back (maybe even a small patch in a particular location) and grounding it would be all you need. This should have been done internally by the manufacturer, I suppose, and still could be done if it's possible to take the guitar apart and access whatever electronics are inside.

You tried an experiment with putting the blanket on top of the guitar and it was found ineffective, you may want to try the same with the guitar upside down. This would confirm if it's the particular side of the guitar or separation from the floor that makes the difference. I expect the former.

No idea why your location is so bad. The source of electric fields is voltage, and the source of strong AC electric field is high voltage AC.
 
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Offline DaveNJTopic starter

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Re: Home recording studio - noise with guitar amps - who to call?
« Reply #42 on: November 22, 2022, 02:23:08 pm »
I have no experience fighting with low frequency magnetic fields, but people say that they are a bitch to block, basically requiring thick solid steel or stuff like that.

OTOH, the behavior you show is perfectly consistent with (perhaps unusually strong) electric field. These fields are stopped simply by surrounding the sensitive circuit with any reasonable conductor connected to the circuit's ground. It looks like something internally at the back of the guitar is receiving the noise. I guess that sticking a layer of aluminium foil to the back (maybe even a small patch in a particular location) and grounding it would be all you need. This should have been done internally by the manufacturer, I suppose, and still could be done if it's possible to take the guitar apart and access whatever electronics are inside.

You tried an experiment with putting the blanket on top of the guitar and it was found ineffective, you may want to try the same with the guitar upside down. This would confirm if it's the particular side of the guitar or separation from the floor that makes the difference. I expect the former.

No idea why your location is so bad. The source of electric fields is voltage, and the source of strong AC electric field is high voltage AC.

Thanks - you're correct, flipping the guitar over does not provide a full cancelation until I wrap the fabric up over the top (back of the guitar) as well. I think I show this in one of the videos...
 

Offline jonpaul

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Re: Home recording studio - noise with guitar amps - who to call?
« Reply #43 on: November 22, 2022, 03:21:25 pm »
get a better guitar pickup, hum bucking

j
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Offline DaveNJTopic starter

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Re: Home recording studio - noise with guitar amps - who to call?
« Reply #44 on: November 22, 2022, 03:49:09 pm »
get a better guitar pickup, hum bucking

j

It is.
 

Online fourfathom

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Re: Home recording studio - noise with guitar amps - who to call?
« Reply #45 on: November 22, 2022, 05:42:44 pm »
get a better guitar pickup, hum bucking

Better?  Better in the hum department, but I personally love the sound of the single-coil Strat and Tele.  That's why the piezo pickup may not be *the* solution, although you can do amazing things with modeling boxes these days.
We'll search out every place a sick, twisted, solitary misfit might run to! -- I'll start with Radio Shack.
 

Offline jmelson

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Re: Home recording studio - noise with guitar amps - who to call?
« Reply #46 on: November 22, 2022, 05:46:53 pm »
In video 03, it was VERY obvious the noise got louder when the guitar was flat on the floor.  Is that room the lowest level of the house?  IE, a poured concrete floor?  If so, there could be electrical conduits buried in the concrete.  If not the lowest level, there could be unshielded Romex wires in the space below the floor.  Holding a guitar with magnetic pickups next to electrical wiring would be a SURE way to pick up noise.
I'm QUITE impressed by that "belly armor" it is one of those tinfoil hat products that ACTUALLY does what it is supposed to!  But, magnetic pickups are really terrible receivers of magnetic interference.  try some PZMs, they should be a LOT less sensitive to this stuff.  Where is the main breaker panel for the house?  If near where you made these videos, there will be HUGE bundles of Romex branching out from the panel, either in ceilings or floors near there.

Jon
 

Offline DaveNJTopic starter

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Re: Home recording studio - noise with guitar amps - who to call?
« Reply #47 on: November 22, 2022, 06:00:14 pm »
In video 03, it was VERY obvious the noise got louder when the guitar was flat on the floor.  Is that room the lowest level of the house?  IE, a poured concrete floor?  If so, there could be electrical conduits buried in the concrete.  If not the lowest level, there could be unshielded Romex wires in the space below the floor.  Holding a guitar with magnetic pickups next to electrical wiring would be a SURE way to pick up noise.
I'm QUITE impressed by that "belly armor" it is one of those tinfoil hat products that ACTUALLY does what it is supposed to!  But, magnetic pickups are really terrible receivers of magnetic interference.  try some PZMs, they should be a LOT less sensitive to this stuff.  Where is the main breaker panel for the house?  If near where you made these videos, there will be HUGE bundles of Romex branching out from the panel, either in ceilings or floors near there.

Jon
Jon,

The room is the video is an extension over a crawl space. There is no wiring that runs under there - all outlets for that room run through the 2x6 framing in the walls. This room is also on the opposite side of the house from the breaker panel.

Using the EMG pickups did what they're supposed to do - they're totally silent. but, they really don't sound as good as standard mag pickups. I'm certainly not going to put one in my 59 Junior!

I was amazed that this blanket worked as well! I saw some teardown of these supposed EMI blockers which look like they're just three pronged plugs with some electronics inside, but they're just filled with epoxy! Haha!
 

Offline magic

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Re: Home recording studio - noise with guitar amps - who to call?
« Reply #48 on: November 22, 2022, 06:42:47 pm »
I'm QUITE impressed by that "belly armor" it is one of those tinfoil hat products that ACTUALLY does what it is supposed to!
No, it does something else. If you want to know how effective it is for its stated purpose, put a phone under your shirt, wrap yourself in that blanket and try to call the phone.

I bet it will ring :P
 

Online ebastler

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Re: Home recording studio - noise with guitar amps - who to call?
« Reply #49 on: November 22, 2022, 08:18:44 pm »
But, magnetic pickups are really terrible receivers of magnetic interference. 

But it can't be magnetic interference if it is shielded by a sheet of grounded metallized fabric, right? Must be electrical fields?
 


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