Interference from PC - Help!

MackieFX

MackieFX

Experienced
Most of my presets are high gain with a noise gate so I don't really notice interference.

I wanted to play with some mid gain amps yesterday and it was unplayable.

My guitar (which is shielded) is picking up EMI from my computer - the closer I have my guitar the worse it is. This interference is also present when I sit far away from the computer so It seems like its interfering in general.

I don't know what the solution is here but if someone could help Id really appreciate it.
 
I was going to ask this as well. It's not superbad here, but noticeable.

My solution is just to turn and face away from the monitor. Curious what
real solutions might be out there. :)
 
I was about to create a similar thread.

Since I got the FM3 I play in front of the computer at least 95% of the time. I don't have a lot of space in my flat, thus I have my computer mounted below my desk, next to my right leg. Since I am right handed that means that the guitar usually faces my computer directly.

"Just position yourself away from the noise source" doesn't work for me, because I need to interact with the PC for tone configuration, DAW control and tab reading.

What I already did to reduce the noise floor:
  • Got a Truetone 1Spot CS7 for my pedal board. It's a switch mode PSU that has no problems when mounted below the pedal board. That helped a lot compared to my harley benton psu.
  • Got a nice instrument cable (Sommer cable, with Neutrik connectors) for guitar to pedalboard and high quality pedalboard cables (EBS High Performance)
  • FM3 is connected with XLR to my audio interface, my studio monitors and wireless IEM are connected with TRS (balanced connections)
  • Used the Output Leveling for all presets and adjusted the FM3 global output level to my audio interface to hit around ~-10db on the input (no input gain on audio interface)

Next up:
- I ordered ferrite coils from amazon to put around existing power cables

What I could do, but currently refrain from doing:
  • Shield all my guitars with copper (the electrical cavities)
  • Buy an EMI / RFI meter to really pinpoint the source of noise. Maybe I could borrow one somewhere.
  • Replace the glass panel from my computer with a solid metal one (see also Comment from Cliff)

What I am still curious about:
- How to reduce the EMI/RFI from the computer itself?
 
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I am going to soak up all the info and tips from this thread that I can. :)

I don't know what to do right now, other than turn my back to the monitor
when I play. Definitely some kind of magentic field interference between
the pickups and the monitor.
 
I was creating a new one post and i see this when typing.

I have this noise(attached files with VOLUME TURNED UP TO ENANCE THE NOISE ITSELF) captured from my S..Coil (with Humbucker is still present but lower noise) ,
i have glass panel from the side of my mini tower, i thought some UPS could mitigate this noise ?


Any other tips ?
 

Attachments

  • Noise.zip
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astefanello said:
I was creating a new one post and i see this when typing.

I have this noise(attached files with VOLUME TURNED UP TO ENANCE THE NOISE ITSELF) captured from my S..Coil (with Humbucker is still present but lower noise) ,
i have glass panel from the side of my mini tower, i thought some UPS could mitigate this noise ?


Any other tips ?
Click to expand...

As a starter: replace the silly glass panel with a metal panel. Otherwise you will never get rid of that, unless you move away from the computer

Read these other threads:
https://forum.fractalaudio.com/thre...noises-when-turning-on-pc.151624/post-1804267
https://forum.fractalaudio.com/thre...ise-on-sustained-notes-w-single-coils.173539/
https://forum.fractalaudio.com/threads/terrible-humming-please-help.171666/
 
For your PC, monitor and FM3 be sure your using a good quality power conditioner, this makes a world of difference, also make sure your outlet is correctly grounded to a cold water pipe in your home, incandescent light bulb dimmers are notorious for making noise, switch all lightbulbs on your circuit for LEDs (my opinion) this also makes a big difference, finally my PC is located in a dedicated pocket area in the wood cabinet and I do not have a see through case not sure how much emi this reduces but I do not have these problems here.
 
Boy do I have this problem, EJ strat, single coils. Is one of the main reasons I edit on the front panel mostly, so I can leave the laptop off, or stay away from it if it's on.

The high buzz bothers me more than hum.i haven't done everything humanly possible to shield the guitar, which I probably should, but some folks say that hurts high frequency response.

I've never been happy with the tone of the humbucking strat pickups I've tried in store guitars, but that's another option. I'd probably want a cheaper guitar to try that on, no point in the EJ mojo going to waste.
 
I have noticed that most of my noise comes from the computer monitors. I have 2-32" LED monitors and they seem to put out a lot of noise. If I turn my back to them the noise goes away. For dialing in tones, I will usually use a looper block and record a section that I want to use to dial in the tone. I can then let the looper play and adjust whatever settings I need.
 
FractalAudio said:
Get rid of the glass.
Click to expand...

Would covering the window with copper foil tape block EMI as long as the copper foil is touching bare metal on the case panel and tested with a multimeter for continuity around the entire case?

What's strange is I have the opposite issue. My older PC had a glass or plexiglass window and didn't cause much noise. My new PC doesn't have a window but causes more noise. o_O
 
If you really want to know how faraday cages work, read this paper on the mathematics behind it. Theirs is a simple 2D model, but that's the best way to illustrate the concept simply. Their model is also kinda the opposite of what we all want--they are modeling an electromagnetic source outside of the faraday cage and measuring the effective blocking inside the cage. We want the opposite, to block the computer from the rest of the world (i.e. our guitars). The math is likely very similar.

Long story short, yes, you can block electromagnetic signals with conductive materials--more blocking effectiveness with bigger wires and less distance between them. Yes, there is a frequency response (effectiveness dependent on frequency of EM emissions) and the paper merely glosses past the topic a bit, calling it "out of depth" for their work. They don't talk about solid materials, either unfortunately. Intuition likely is your best friend here (bigger and thicker and more sealed is going to provide better isolation, I'd bet).
 
wulftone said:
If you really want to know how faraday cages work, read this paper on the mathematics behind it. Theirs is a simple 2D model, but that's the best way to illustrate the concept simply. Their model is also kinda the opposite of what we all want--they are modeling an electromagnetic source outside of the faraday cage and measuring the effective blocking inside the cage. We want the opposite, to block the computer from the rest of the world (i.e. our guitars). The math is likely very similar.

Long story short, yes, you can block electromagnetic signals with conductive materials--more blocking effectiveness with bigger wires and less distance between them. Yes, there is a frequency response (effectiveness dependent on frequency of EM emissions) and the paper merely glosses past the topic a bit, calling it "out of depth" for their work. They don't talk about solid materials, either unfortunately. Intuition likely is your best friend here (bigger and thicker and more sealed is going to provide better isolation, I'd bet).
Click to expand...
the company I worked for seriously considered this FC when adjacent floors wireless devices and PA's were affecting communications, IT person be aware of older class A high rise buildings as wireless communications can b crippled without one these days...
 
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