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dealing with electrical noise

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16 hours ago, mettelus said:

That wire is definitely an antenna, but make sure you know where it really goes before playing with it. The rest of the wiring in the house can be acting similarly to your environment.

Since your house is of the older 2-wire style, it would be worth your time to go through the breaker box and verify circuits (I *hope* you are not fuse-panel, but you could be). Heavy appliances with motors (refrigerator, AC units, fluorescent lighting, furnace) and things you turn on (vacuums, microwaves) can all be feeding back into the house itself. You can control most of those, but the ones that kick on automatically (refrigerator and furnace) are ones you may want to check for feedback. *If* the refrigerator being on/off is a noticeable difference, that is one appliance you may want to make sure is offline when recording.

It also made me wonder with the GFCI comment... where is the ground on that running? If connected to a 2-wire circuit, it may still not have a ground.

 

I was told the wire coming into the house was an antenna for a ham radio.

Before we moved in, we had the breaker box redone, so it's no longer a fuse panel.   

as for the GFCI, we had an electrician do it simply because the outlets had only two prongs.   I needed something with 3.   And we cannot afford $10,000 + to rewire this house right now.  So GFCI was the only alternative for the moment.

 

I don't notice any difference with appliances being off or on - at least i haven't yet.

Edited by greg54

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On ‎3‎/‎5‎/‎2019 at 8:04 AM, greg54 said:

Thanks!   And i'm using a Scarlett 2i4 

 

This- Those are USB buss powered and there have been a few threads as well as I helped a friend with this issue once. The hum is probably coming over the USB power so the best solution is to use a USB cable with a Ferrite choke.  It's one of the reasons I don't recommend interfaces that ONLY have USB power.  It's better if they offer the option of a proper power supply. The other issue they can have is a starved 48 volt phantom power for some LDC mikes.

 

pearstone_usb_amb04fb_4_hi_speed_usb_type_852758.jpg

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1 hour ago, greg54 said:

Before we moved in, we had the breaker box redone, so it's no longer a fuse panel.   

as for the GFCI, we had an electrician do it simply because the outlets had only two prongs.   I needed something with 3.   And we cannot afford $10,000 + to rewire this house right now.  So GFCI was the only alternative for the moment.

I am with you about not wanting to re-wire the house. The grounding is my real concern, and you can ground that specific circuit to your equipment. The house itself should have an earthen ground on it to the breaker box (can ask the person who did the work to verify), but I am not sure if the GFCI is really grounded. In some older homes I have seen them run earthen grounds through walls to ground individual circuits (copper wire to metal stake outside the home). My concern is that the GFCI circuit may not really be grounded, but just replacing a 2-prong outlet with a 3-prong (with no functional difference other than another hole). The electrician who installed that should be able to answer what they did... just so they don't BS you (installing a GFCI with no ground may be a code violation there), ask them "where is the ground on that GFCI you installed, and how is that a common ground for the house?"

Edited by mettelus
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I missed the post above mine,

If this is an older home that was not originally wired with a ground circuit and all they did was upgrade the panel.  Then if they did not upgrade the wiring you will need to at least run a grounded wire directly to the new panel either with a appropriate extension cord or somehow install at least that one circuit.

Hopefully they would have properly grounded the new panel and supplied you with at least one grounded outlet. A GFI is pointless if it is not grounded.

You can test outlets with one of these inexpensive testers.  I never go anywhere without mine. 

 

 

ideal-voltage-tester-61-035-64_1000.jpg

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Cactus Music:  I ordered the usb cable with ferrite choke.  Thanks!

And when the electrician did the GFCI outlets, he used that very tester to see if it was grounded.  So I guess I just answered the question.

metteus:  We remodeled the kitchen and bathrooms before we moved in, and all those rooms are grounded.  We just didn't have the extra money to rewire the entire house.   

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On 3/5/2019 at 3:33 PM, Sean Michael Robinson said:

<...snip...> And in one case, my bandmate found out (the hard way) that he was located right near the broadcast tower of the local NPR station. How did we know? His Fender Bassman (and several of his older ribbon mics, including two Beyer 16os) started picking up the station almost as loud as any audio coming into them! We had to rotate/reorient them (and the guitar cable) in the room to avoid the problem.<...>

I have two radio stories:

1) I used to live near a college campus. Their radio station tower used to be miles away at remote campus extension but they decided to put it on the main campus. It was so close that if it toppled, the tower would hit my house. I got WQCS in everything. My stereo set, my amps, my reel-to-reel tape deck, and the TV. I complained to the FEC who send out an engineer who also was the engineer hired by the radio station. Needless to say, nothing got done. Since I was renting, I eventually just moved.

2) Played a grand opening party on the parking lot of an office building right next door to an AM radio station in Stuart Florida. The people heard the radio in their wired phones and everything else. I sensed trouble right from the start.

We set up the PA and of course had the radio station coming out our speakers. In a rare bit of insight and luck I saw a water pipe bib and spigot next to the building, I scraped paint off a bit of the pipe and it was copper (it was an old building). So not knowing if it would work, but grasping at straws, I hooked my vehicle's jumper cables to the scraped pipe and the other end clamped to my road rack rail. Problem solved, and the gig was saved.

Insights and incites by Notes

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15 minutes ago, Notes_Norton said:

2) Played a grand opening party on the parking lot of an office building right next door to an AM radio station in Stuart Florida. The people heard the radio in their wired phones and everything else. I sensed trouble right from the start.

We set up the PA and of course had the radio station coming out our speakers. In a rare bit of insight and luck I saw a water pipe bib and spigot next to the building, I scraped paint off a bit of the pipe and it was copper (it was an old building). So not knowing if it would work, but grasping at straws, I hooked my vehicle's jumper cables to the scraped pipe and the other end clamped to my road rack rail. Problem solved, and the gig was saved.

Cool Story.

First home was covered in Aluminum siding and the roof insulation had the old stuff with the metal reflective backing. It was like a huge antenna. Needless to say Murphy's Law set into motion with three radio transmitters within miles of house. When I plugged in Amps I got AM radio all the time. Glad we only lived there for 3 years.

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These stories put me in mind of my old Fender Bassman that had a 2 prong plug.  As most of you will remember how "safe" those were.  But you usually knew when you had to flip the reverse switch as you most always heard a hum. Otherwise you would be blown across the room when you touched your mike with your lips! But one of the benefits was if I turned the amp up it picked up AM radio and I used to listen to it in my room that way. 

The other thoughts on this topic is how many people these days are freaked out about RF emissions from Smart meters and cell towers. They talk like this is some sort of new heath issue. Most of those old radio towers blasted out a lot more RF energy than a cell tower.  And there also was all the TV station towers which are now gone. 

Greg- The ferrite choke worked for my friend who had the hum in his 2i4. I hope it works for you.  All my USB audio gear now have those type of USB cables. They are a good idea. I even have power supplies ( wall Warts) that came with a choke on the low voltage side. It's a bad on Focusrite's part that they don't include one of these cables as it would seem the right thing to do.  

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I was having a bad hum on all my guitars, acoustic plug-in and electrics, single and double coil and humbuckers, but only in one room in my house..  Turning 90 degrees and keeping the guitar exactly perpendicular to the ground helped somewhat but it was always there - regardless if I was plugged into an amp, FX pedals, a DI to my interface or directly into my interface.  But nothing else hummed.  I never thought "premium" cables did much good but I invested in some short (6 ft.) Mogami gold cables and ran them wherever the guitar signal went (to and from FX units, pre-amp, amp, interface, etc.)  Voila NO HUM. 

I finally realized it was because the room is over the garage and the garage door opener is creating some kind of electrical field (even when the mechanism is not running) that the guitar signal was picking up through the cheaper cables, even though they were decent shielded Fender and similar cords.   But absolutely no hum with those Mogami Golds.

Not sure this will help you if everything has noise and static.

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10 hours ago, Cactus Music said:

These stories put me in mind of my old Fender Bassman that had a 2 prong plug.  As most of you will remember how "safe" those were.  But you usually knew when you had to flip the reverse switch as you most always heard a hum. Otherwise you would be blown across the room when you touched your mike with your lips! But one of the benefits was if I turned the amp up it picked up AM radio and I used to listen to it in my room that way. 

The other thoughts on this topic is how many people these days are freaked out about RF emissions from Smart meters and cell towers. They talk like this is some sort of new heath issue. Most of those old radio towers blasted out a lot more RF energy than a cell tower.  And there also was all the TV station towers which are now gone. 

Greg- The ferrite choke worked for my friend who had the hum in his 2i4. I hope it works for you.  All my USB audio gear now have those type of USB cables. They are a good idea. I even have power supplies ( wall Warts) that came with a choke on the low voltage side. It's a bad on Focusrite's part that they don't include one of these cables as it would seem the right thing to do.  

Ferrite choke's certainly can help. I actually use one in combination with a ground isolator, as the choke on its own didn't remove all the noise. 

FYI - you can buy clip-on ferrite choke's to fit on existing cables. Just do a search on Amazon/ebay for ferrite choke, and you'll see plenty of options - be sure to get one to match  your cable thickness. Prices are around $1 to $3.

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I honestly hope the ferrite choke does the job. But I don't think its going to. When you put powered speakers, next to a powered Desktop monitor, through a powered soundcard using 2 prong outlets your in for a long day.

@greg54 You can about this any way you choose but as I said previously, Its a matter of process and elimination.

Start with the basics, Plug your 5 power sources (Desktop, Video monitor, Soundcard and 2 Speakers into one power strip.

1- Power up Desktop / Soundcard / Speakers

2- Find the grounding sound you are hearing. Once it is strong, Turn off the Video monitor to your desktop (you just eliminated 1 source).

3- Turn off 1 Speaker (it could be a bad cord to your speaker) Now repeat with the other speaker.

Your best bet might even be to lug your gear into the kitchen (where the wiring has been updated) and check it there. If it works fine there, chances are no ferrite choke will help you.

 

 

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This is only semi-related, but a 'road story' about hum.

I've been in the same duo since 1985 and we're still making a living by gigging. Part of the reason for that is we went into the private party / yacht club / country club / condominium / retirement development when the MADD mothers with their good intentions started ruining the night club business.

On the gig I plug everything into a power conditioner to keep all the ground potentials similar. The power conditioner keeps both surges and dips from destroying my synth modules and other gear.

One place that hires us a couple of times per year, and has been doing this for over a decade has a strange problem.

I play sax, wind synth, flute and guitar on the gig and my guitar has Seymour Duncan P-Rail pickups. The P-Rails can be configured for P-90, Rail, Series Humbucker or Parallel Humbuckers with a few slide switches. In this particular room, if I have the selected pickup(s) in either of the single coil modes (P90 or Rail) the hum is deafening.  In either humbucker mode it's quiet.

When I get there, I've learn to put both pickups in the humbucker mode before I start playing. I'm glad it's a simple fix.

I have no idea what the problem is, and the person who hires us says other groups have had problems with hum too.

Insights and incites by Notes

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I appreciate everyone's input.    I am doing everything in order to find the solution - the ferrite choke, ground lop isolator, plugging computer into separate power strip than monitors, etc.    But i also have to somehow get rid of the ham radio wire sticking out of my wall.  My room is not near the kitchen or laundry room.   It's at the other end of the house, so there's nothing near it that would cause interference, except for the radio wire. 

Since the issue is with recording gear, I don't know if the Mogami cables would make a difference.   But to be honest, I'm tempted to try.

Thanks Everyone!   Perhaps doing everything will fix it.

Greg

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All these stories about the Fender Bassman are bringing back memories ... man, those things can kill ya. Got zapped recording at a really nice studio (RIP Chromasound) where the Bassman was next door so it could operate at the typical jet-engine levels. Problem was, it was on a separate power system from the main room, where all the rest of the gear was, including a SM58 for scratch vocals, were. Stepped up to that badboy with my guitar plugged in-- ZAP from about an inch or two away, that sent be back and to the floor. I feel very lucky it wasn't my bandmate/cosinger who was shocked (she was about a foot shorter than me, seventy pounds lighter, and had a metal lip ring at the time!)

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I went ahead and ordered the Mogami cables.    If it helps a little, it's worth it

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Always good to have top quality cables.  

My cable story was this;

I ran a music store for 12 years.  One day a guy came in and was looking to buy a new Bass as he said his sounded muddy. 
I plugged it in using my amp and cable and it sounded fine... he goes what did you do? I looked in his case and he had this Curly cable,,, we hooked that up and his bass was real real muddy. I didn't sell him a $300 bass but I did sell him a $30 cable. The ones I sold and I still have in my own collection were all Beldon wire with Switchcraft ends made by Cabletech ( now called Radial) .  25 years and counting. 

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"Electrical noise" is a diagnosis without a symptom. Basically there are two major categories, usually with different causes. One type is hum and most commonly that comes from the circuit either being polluted by a regular source of AC voltage like a  motor or dimmer on the circuit, or the wiring or components receiving a broadcast of electromagnetic  waves like a nearby neon sign,  crossed wires or  components leaking electromagnetic waves. Ground loops or inadequate grounding often accentuates hum. The other is often described as "static" when what is really meant is an irregular crackling sound, which is most often due to bad or dirty connections somewhere which may be widely propagated through the system. Static electricity does not generally produce audio interference, since it is just a voltage difference without a current, but the discharge of static electricity may have a very high voltage that will get through a lot of conditioning and need not be in direct contact with the circuit to have an impact.

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Another cause is the  use  of unbalanced cable between audio interface and monitors aso.

Wiring everything balanced throughout will get best rejection from hums etc with fully balanced kit unfortunately there is so much unbalanced stuff you get compromised.

Edited by Pragi

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On 3/5/2019 at 3:04 AM, msmcleod said:

I use a ground loop isolator like this, between my audio interface and my monitors:

image.png.8a747bd6e781b49f6f55376a867020c6.png

They're around $9 / £6 from Amazon.

Do they make those for 1/4" TRS cables?

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1 minute ago, abacab said:

Do they make those for 1/4" TRS cables?

No, but I just use a RCA to 1/4" adapter:

phototojack.jpg.1b51746f928237d1c8cd7dbf1fbb1f21.jpg

It does force you to use unbalanced cables though, but I mainly use it for output signals.

I find balanced cables are vital for input signals, where you're having to amplify a fairly weak signal coming in.

For outputs, especially line level or amplified signals, the benefit is less pronounced.

 

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