Eliminate static crackling noise when scrolling Scarlett 2i2 interface


This issue has been driving me crazy for years now to the point where I was using only single monitor for the last half year. There is a crackling noise at idle and a much more pronounced noise when scrolling or doing certain other graphical tasks such as gaming.

I have KRK Rokit 6 G1 and G3 monitors along with Focusrite Scarlett 2i2 USB interface. The KRK Gen 1 doesnt have this issue but G3 does, I even replaced the G3 and it still has this issue so its not the monitor alone that is causing the issue. I did try swapping the balanced 6.35mm cables and power cables between G1 and G3 with no change so its not the cabling either. The issue persisted with both older and newer model of the 2i2 interface. Using different power socket may improve the issue somewhat but its still there. Using different USB ports on the PC makes no difference either. House is relatively new, built in the last 15 years so I would expect wiring to be ok.

If I plug the 2i2 USB port into an unplugged laptop issue is gone. What I do not understand is why isn't the audio interface eliminating noise? I mean the whole point of a DAC is to take audio processing outside of a noisy PC environment. What is the point of a DAC if it fails like this? I just don't get how noise could travel via USB port which is digital and survive ADC process. Is this just bad design of the 2i2 interface? What is causing the issue and what can I do to eliminate it? It really seems like the USB DAC is what should be eliminating the issue not causing it.


Posted 2020-02-26T19:37:23.607

Reputation: 151

are you hearing the same sound on headphones? – Mark – 2020-02-26T20:58:34.237

are you using a common ground between the computer device an the speakers? – Mark – 2020-02-26T20:58:49.530

By the way, it's probably not your interface, it's probably more to do with the mains grounding setup between the computer and the speakers. – Mark – 2020-02-26T20:59:55.257

Everything is plugged into 1 of the dual socket wall plug and headphones sound 100% clean. Also noise when scrolling is not affected by volume, its present even with min volume. – DominicM – 2020-02-26T21:07:41.263

@Mark The reason I blame the DAC is that I see no reason why a digital device would pass noise from USB port to analog out, that just seems like a massive design flaw to me but that's just me. – DominicM – 2020-02-26T21:09:00.690

The reason you can't solve the problem is becuase you keep blaming the DAC. It's not the DAC. You've already said the G1 KRK's don't have the same issue. It's not the DAC. It's something to do with the power configuration of your system, but it's not the DAC. – Mark – 2020-02-26T21:12:38.683

Check out USB Ground Isolators. – Mark – 2020-02-26T21:13:50.937

@Mark I am not saying that replacing the DAC would fix the issue but I am pointing out how ridiculous it is that a digital device passes analog noise over a digital interface. I mean if I bought 40€ speakers and plugged directly in to integrated audio I would not have this issue but with 150€ DAC and 400€ Speakers I have this issue, I just dont get how thats being accepted by seemingly everyone. – DominicM – 2020-02-26T21:19:55.973

I think you need to do a bit of self-learning on how these devices work. Yes, USB is a digital interface, however there is a ground/shield associated with the interface which is common across both digital and analogue circuits. When a signal passes across this ground connection, it will make it's way into the analogue signal output and you will hear it. Hence, my suggestion to investigate ground isolation for your USB. – Mark – 2020-02-26T22:09:54.017

Let us continue this discussion in chat.

– Mark – 2020-02-26T22:10:58.903

No answers