Should a computer case have electrical continuity to ground?

1) Are you sure the computer is the main culprit? Does the EMI get worse when your guitar is close to the PC?

2) Have you ruled out the monitor, other peripherals, wireless router, light dimmers, etc?

3) Flipping a PC's motherboard usually isn't an option because the mounting holes won't line up with the case anymore.

4) There's not much point in putting copper lining on a metal case. :)
 
Those fractal cases aren’t good for EMI. Lots of plastic and the tool less drive mounts leave the drives floating. Nothing beats the good old fashioned cases with everything screwed down hard.
 
Managed to do some isolation. Looks like lots of leakage from the PSU and the Mobo. Quite far down the rabbit hole now, so will probably try one of my spare PSU's just in case, otherwise maybe upgrade to a pricier board with a bit more shielding going on.
 
Those fractal cases aren’t good for EMI. Lots of plastic and the tool less drive mounts leave the drives floating. Nothing beats the good old fashioned cases with everything screwed down hard.

Wow, thanks for chiming in Cliff. You're a legend. I'll scour the internet and see what I can come up with, unless anyone has any good recommendations. Maybe something rackmount style could be the way to go.
 
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Wow, thanks for chiming in Cliff. You're a legend. I'll scour the internet and see what I can come up with, unless anyone has any good recommendations. Maybe something rackmount style could be the way to go.
Wife just did s build with a Be Quiet! case and I was rather impressed by it. It’s very quiet. And the case was nice to work with.

 
Thanks dude, i did take a quick look and saw all their cases have plastic/glass sides though i think?

- Actually i take that back. Looks like there could be something!
 
A guy I know reckons the issue will go away if I install a dedicated ground to my studio room. Not sure I'm convinced though . Reckon it's worth a shot, or just try a new case?

Think my house is earthed in a tnc-s PMC manner so it has multiple grounding points by the looks of things.
 
A guy I know reckons the issue will go away if I install a dedicated ground to my studio room. Not sure I'm convinced though . Reckon it's worth a shot, or just try a new case?
A dedicated ground for the studio can only help with ground loop issues. It won’t touch EMI.

If you decide to try it, make sure you have a solid, low-impedance path to ground, and establish a star grounding system to a common bus bar. Also, be aware that an independent ground system requires that you disconnect the ground from the power cords on each piece of equipment. If that’s not done correctly, you have major safety issues. That’s work for a licensed electrician, unless you really know what you’re doing and you don’t care about the legal and financial liability of violating code.
 
Steel case i found hasnt really made a lot of difference. Directly grounding the rig to a pole in the garden has made no difference. Had a brain wave that the d15 i have (huge chunk of metal heatsink) could be an antenna next up, so grounded that too. Nothing.

Next options:

Power conditioner (in the hope of mains causing it)
New mobo
Different brand of PSU to seasonic/corsair. (tried a corsair and it made no difference.)

The emi is massive around the PSU (naturally i guess) but im thinking perhaps the board could be to blame for it, maybe radiating it back in somehow. It just seems like it has some kind of internal ground loop from hell going on.

Should have bought a Mac right :D :D
 
Can you record the noise? Are you sure is THAT much?
There is gonna be some noise no matter what and you probably could spend your energy to improve the shielding of the guitar instead or simply learn to manage the noise with the guitar volume and channel switching.

I hope this sounds helpful and not dorky...
 
Little update on this issue- i borrowed a small form factor HP to test in the same location. Barely interfered at all, almost zero unless i got the pickups very close to it. My final 2 stages of elimination for the rig are testing with a UPS this week followed by a more expensive motherboard.
 
Little update for you googlers who hit this one day.

A UPS did nothing to solve the problem, so it is contained EMI. However, a new x470 motherboard has cut this by 75%, now a perfectly manageable level. I'm still currently tweaking out settings, but i believe it is motherboard VRM stages & coil whine causing this issue. I'm trying to get everything running flat out, looking at spread spectrums and ironing out as much as possible to provide constant voltage so that my pickups don't amplify these fluctuations.

I did believe the graphics card was having a part to play as well as the noise is induced on mouse and window movement, however from certain research i'm inclined to think it is CPU related.
 
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