barbz127 Posted October 16, 2019 Share Posted October 16, 2019 (edited) Hi all, Apologies for the formatting; I'm looking for some guidance on where to go next to remove some noise from my system - and what I have tried so far. My issue is I get what I can describe as computer noise through the headphones at medium-high volume - the sound is constant but changes when I move the mouse. My setup is PC based only (home office) and headphones: Desktop PC (evga g3 750w psu low noise according to jonnyguru) -> wireworld ultraviolet 7 usb (2m) -> Gieseler Klien 3 (with lps) > woo wa6 -> headphones. The room has 2 double gpo's with earth wired up - the dac and amp each have their own socket and the computer is connected to a commercial APC ups (along with some switches, nucs, synology nas, etc). What I know Resistance between the computer earth (via the UPS) and wall socket is 0.6ohm DAC & Amp are silent with the USB disconnected from the desktop DAC & Amp are silent if connected to my laptop not on AC Ifi igalvanic reduces the noise when used inline but is prone to audio dropouts (common if grounding issues are present) - this is regardless of the setting used Noise was there on previous DAC - schiit 3 Noise persists if UPS is running on battery Noise persists if desktop is connected to the 4th wall socket or a powerboard with the DAC & Amp Noise persists if desktop is connected to the 4th wall socket and the UPS is disconnected from the wall Noise persists if wireless is powered off System is silent if UPS (with desktop) is connected to a different GPO circuit but DAC & AMP remain as they were Noise persists if all items are run from a separate GPO circuit. What else can I be checking to figure out the cause? Thankyou Paul Edited October 16, 2019 by barbz127 Link to comment Share on other sites More sharing options...
Ittaku Posted October 16, 2019 Share Posted October 16, 2019 Is the noise there with the PC on the same GPO circuit as the DAC, but with the USB disconnected? I couldn't tell for certain but that's what you implied. That would suggest the noise is all coming down through the USB connection, and not being reinjected into your mains. You're probably getting USB interrupt noise from the PC PHY (device that generates your USB signal.) A USB cable with the power line separate may go partway towards alleviating this but it sounds like you have noise on the actual data line as well. You need some pretty hefty USB decrapifying, and the ifi being partially effective suggests that to be the case. Perhaps get hold of a USB to SPDIF converter which is more effective than just regenerating the USB. The best value option is the Gustard U12 a bit over $200, but see if you can borrow one first to see if that helps. Link to comment Share on other sites More sharing options...
barbz127 Posted October 16, 2019 Author Share Posted October 16, 2019 Just now, Ittaku said: Is the noise there with the PC on the same GPO circuit as the DAC, but with the USB disconnected? I couldn't tell for certain but that's what you implied. That would suggest the noise is all coming down through the USB connection, and not being reinjected into your mains. You're probably getting USB interrupt noise from the PC PHY (device that generates your USB signal.) A USB cable with the power line separate may go partway towards alleviating this but it sounds like you have noise on the actual data line as well. You need some pretty hefty USB decrapifying, and the ifi being partially effective suggests that to be the case. Perhaps get hold of a USB to SPDIF converter which is more effective than just regenerating the USB. The best value option is the Gustard U12 a bit over $200, but see if you can borrow one first to see if that helps. Thankyou - I can confirm there is no noise if the USB is disconnected regardless of how the power to each item is fed. My dac is USB only so the adapter wont work - will be something I'm conscious of next time I purchase a DAC. If I can figure out why im seeing usb drop outs with the Ifi then I will be satisfied. Paul Link to comment Share on other sites More sharing options...
sakabatou Posted October 16, 2019 Share Posted October 16, 2019 I had a similar problem last year, and a Wyred 4 Sound Recovery solved it for me Link to comment Share on other sites More sharing options...
Ittaku Posted October 16, 2019 Share Posted October 16, 2019 This may sound crazy, but try a cheap powered USB hub first between your PC and your DAC. Many manufacturers of so-called decrapifiers just rebadged fancy USB hubs. The PS audio lanrover is a perfect example. The startech USB network cable extender does exactly the same thing for much less. Link to comment Share on other sites More sharing options...
barbz127 Posted October 16, 2019 Author Share Posted October 16, 2019 (edited) 33 minutes ago, Ittaku said: This may sound crazy, but try a cheap powered USB hub first between your PC and your DAC. Many manufacturers of so-called decrapifiers just rebadged fancy USB hubs. The PS audio lanrover is a perfect example. The startech USB network cable extender does exactly the same thing for much less. The one thing that you always had lying around but tossed out once PC's came with more usb ports. Will hunt down a cheap powered one and test. Thankyou Edit - no change when using the usb hub built into the monitor Edited October 16, 2019 by barbz127 Link to comment Share on other sites More sharing options...
barbz127 Posted October 16, 2019 Author Share Posted October 16, 2019 38 minutes ago, sakabatou said: I had a similar problem last year, and a Wyred 4 Sound Recovery solved it for me Thankyou - do you use this with the external power supply? Link to comment Share on other sites More sharing options...
sakabatou Posted October 16, 2019 Share Posted October 16, 2019 yes, I think I used with with a Gieseler linear power supply, but it did work with a switch mode too Link to comment Share on other sites More sharing options...
barbz127 Posted October 16, 2019 Author Share Posted October 16, 2019 Just now, sakabatou said: yes, I think I used with with a Gieseler linear power supply, but it did work with a switch mode too Thankyou - a seperate psu is what this model of igalvanic is missing - the full size model before it allowed for it. Link to comment Share on other sites More sharing options...
Guest Muon N' Posted October 16, 2019 Share Posted October 16, 2019 (edited) I had that happening on my PC once, forget how it was fixed, maybe driver updates. This was with just internal sound device and not using an external DAC. There are likely a bunch of possible reasons for this issue. Did you try a different mouse? Edit: I'm likely on the wrong path but also update the PC's sound driver if it has internal sound. Edited October 16, 2019 by Muon N' Link to comment Share on other sites More sharing options...
barbz127 Posted October 16, 2019 Author Share Posted October 16, 2019 Thankyou Internal sound is disabled in bios, re-enable updated and tested same issue.have tested with a different mouse/keyboard. Sound is evident before the PC has booted so OS / driver independent Link to comment Share on other sites More sharing options...
barbz127 Posted April 24, 2020 Author Share Posted April 24, 2020 Posting this for closure. I spent hours chasing my tail on this, USB conditioners, different computers/power supplies etc. Turn out the root cause is my monitor which is HDMI connected. I don't know if it's an issue with the monitors power supply or something else but the second the HDMI lead is disconnected the USB audio signal is clear of noise. This has been confirmed now with three computers. It's nice to have some closure. 8 Link to comment Share on other sites More sharing options...
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