Ground Loop after changing case and PSU

[drichardb]

Sorry but this is going to be longer than recommended so I can list everything I have done so far...

 

My original config was....
Aorus X570 Pro Motherboard with Ryzen 7 5800X and 32GB Gskill Trident Z Neo 3600 RAM

2TB Sabrent Rocket 4 nvme drive with a 1TB Western Digital Black nvme, both plugged into mobo

Inno 3D GTX 1080
Sound Blaster AE-9
TP-Link Wifi-AC internal card connected to internal usb header
EKWB Watercooling loop with EK Fans connected to motherboard (seperate pump/res)
2 x Corsair red LED Fans
Corsair AX760i PSU
Phanteks Enthoo Pro Case.

Windows 10
Corsair K70 Keyboard
Logitech G502 Mouse
BenQ BL3200 monitor

Sound System connected to PC via analogue cables
Pioneer SC-LX72 AV Receiver
B&W Front and Center Speakers
Logitech satellites
REL T7/x Subwoofer

 

I am based in the United Kingdom with 230v mains power.

Everything running from one extension cord with cables supplied by manufacturer

Everything was awesome. No issues at all.

 

I have rebuilt this system in a Lian Li O11 D Evo case and changed the PSU to a Seasonic GX-1000 and the GPU to a KFA2 3080Ti while changing all the fans to Corsair iCUE RGB

Windows was not reinstalled as no other components were changed

 

Now when I launch into games, once the GPU starts rendering objects on screen you can hear noise from the speakers that changes depending on the GPU load, it is not a constant tone, it is high pitched and fluctuates rapidly.  It is also barely audible when moving the mouse on desktop.

 

I have disconnected/removed everything from the case so that the system now consists of

Motherboard, CPU, RAM and the nvme drives

Onboard audio

Reinstalled the GTX 1080 (even tried an old GTX780)

Gone Back to the Corsair PSU

NO Fans at all briefly with the pump still running

Wired internet

Just the case power switch connected to the motherboard

nade sure to use plain screws and scrubbed the case down to bare metal at the PSU mounting points to ensure the PSU is grounded.

 

Ive disconnected the Display Port able and gone through every possible speaker/interconnect cable combo I can (down to single speaker) and after all of that still the noise persists!!

 

Unfortunately I cant rebuild in the Phanteks case as I gave it to a visiting family member and I don't have an amd air cooler to completely eliminate the loop.

 

Connecting to the amp via optical (both onboard and AE-9) gets rid of the issue but this is not an acceptable solution as the sound quality is poor compared to the analogue connections.  I've also connected a bluetooth speaker that has a 3.5mm input jack to both onboard and the AE-9 and the noise was not present while on battery power and also when connected to the mains charger

 

I've checked every socket available in the room with a tester and all returned correct wiring readouts.

 

To say I'm baffled is an understatement - why would a known good config suddenly go "bad" like this after moving to a new case??

 

Apologies again for the long post but felt it was necessary to provide a full account of the situation to cover off as many questions as possible and hopefully get to a resolution quicker.

 

Any suggestions for next steps (that dont cost money ideally) would be massively appreciated.

 

 

[Hairless Monkey]

36 minutes ago, drichardb said:

Now when I launch into games, once the GPU starts rendering objects on screen you can hear noise from the speakers that changes depending on the GPU load, it is not a constant tone, it is high pitched and fluctuates rapidly.  It is also barely audible when moving the mouse on desktop.

This does not sound like a ground loop. It sounds more like EMI. Given what you have tried already, I'd guess that the geometry and material of the new case is probably making it more pronounced some how.

 

My best suggestion would be to switch to an external DAC and Amp.

 

Also, go into your BIOS and make sure any "Spread Spectrum" settings are enabled.

[191x7]

Have you checked the extension cord?

 

 

[drichardb]

Thanks for the replies

 

If it was EMI shouldnt it have been audible through the bluetooth speaker when connected via a 3.5mm cable?

 

Yes I've tried another extension, no change.

[CostasD]

Have you sorted it out?

Why don't you hook up your old PSU to check if that's the issue?