Microphone Background Noise stops when I touch the case / USB port ?

Update: I tested the headset along with the Xonar USB soundcard on my old PC, which is in the same room but plugged into a different outlet. No buzzing there.

Now I'm guessing that if it were a grounding problem in the house it should have been the same ?

A friend said it could also be something on the motherboard, a bad connection / circuit somewhere ?

Great...

I've opened the case and checked inside. As far as I can see all the connections are good, nothing looks out of place or loose. But then again I suppose it's not looks that matter.

Then I found a cable / wire around and tied one end to the back of the case and touched the other end to an empty socket grounding on my UPS (I have everything plugged in to an APC Backups unit) - this did nothing. But of course if I squeeze the end with my fingers the buzzing stops. Amazing, right ?

Then I unplugged the UPS from the wall socket (it's kind of difficult to reach) and plugged the PC and monitor power cords in there directly, thinking maybe the UPS grounding doesn't work - still the same buzzing. So either my wall socket grounding doesn't work (or isn't grounded at all) or it's obviously something else.

When I snooped around inside the case I noticed that putting my finger on the motherboard or various cables doesn't stop the noise, however just slightly touching the back of the case or the PSU removes it almost completely (just like placing my finger on empty USB port).

I have no idea what to do next (and I'm no tech person either)... Maybe since squeezing the loose end of the wire tied to the case helps I should just get some kind of wristband and just live with the fact that if I want to use the microphone decently I have to strap myself to the computer now. :|

I haven't tried another outlet yet, I need to get an extender from the other one across the room that my TV and old PC are hooked to and connect the UPS to it then see (hear) what happens.

In the meantime, about 10 minutes after I turned on the PC again (after putting the case panels back on and plugging everything to the UPS) now I also have static and crackling on top the buzzing, not the just the normal hiss sound (like in my first recodring form the initial post). Check it out, it's awesome: https://instaud.io/zmS

First minutes after powering on it was just the buzzing, now suddenly that too. What a glorious day !

Getting better and better. Now you can hardly even hear the buzzing because of the static and crackling: https://instaud.io/zn5 :facepalm:

Ok, so just as an update: That horrible static in the recording above kept coming and going for no apparent reason (at one point it disappeared and just the buzzing remained, then out of nowhere it started to come up again).

There was no way to use the mic like that so I plugged out the Xonar U3 from the USB and reactivated the onboard Realtek. I ditched the headset and plugged in my old headphones and the sepparate $3 desktop mic I had, each on their own cable. No more horrible crackling, just a constant hiss which I suppose is normal, all things considered. The buzz was still there, but at a much lower level, barely audible.

Then after I moved the mic around on the desk to find a good position for it, I noticed it's gone! Now get this: if I leave the mic alone on the (wooden) desk, I don't hear it any more, but if I touch its metal part it buzzes again, pretty much the opposite of what was going on with the headset. Go figure!

I'm just going to leave it like it is for now, even though I was looking forward to using a headset mic. I'm starting to think the one I recorded all of the above with definitely has some sort of problem (or maybe it's also the Xonar, though I only plugged it in after people already complained of noises), otherwise I can't explain that crackling coming and going. So far there was nothing like that from the desktop mic and if the buzzing noise only happens when I touch it, I guess this is the best option right now.

All in all I still didn't quite figure it out, but it is what it is...

Anyway, thanks for your time and the replies, much appreciated!

No, the rear ones. When I tried the Xonar I did it on both the front and the back USB ports, no difference.


The case is a Thermaltake Suppressor F31 and the PSU a Seasonic G Series 750W. Also the headset with issues is a cheap Zalman ZM-HPS200 that I just got a few days ago.

I thought it wasn't the headset's fault, because when I tested it for 5-10 minutes on my old PC I didn't hear any buzz or crackling (although I noticed later that the crackling and static comes and goes).

Initially I just hooked up the Zalmans to the on-board Realtek and didn't check the "Listen to device" option in the Control Panel, then got into a game and everyone went "omg what is wrong with your mic ?!" and muted me. Then 10 minutes later it was ok again. Anyway, I thought the crackling and popping noises were interference from the on-board audio, that's why I tried the Xonar U3 on USB and noticed the buzzing issue (with the on-board it was just crackling and all that). Initially on the Xonar it was only the buzz, then the crackling and static also appeared again later. So like I said, I went back to my old headphones and the cheap desktop mic both connected to the onboard Realtek - no more crackling and the buzzing only appears if I touch the metal part on the mic (also with a lower volume than on the USB card).

This is how it sounds now with Microphone volume set to 85 and +20dB gain:
https://instaud.io/ztr

And this is the same setting as above, but with Noise Cancellation on:
https://instaud.io/zts

This is the same setting, without Noise Cancellation, just to show you how it buzzes when I touch the mic's metal part:
https://instaud.io/ztx

So as you can hear, it's much better now. I think that "hissing" sound is normal for that gain / boost and the mic only buzzes if I touch its metal part (plastic base is fine). I'm still not sure about what causes the buzzing sound to act like that, but since now it's not a constant thing anymore I'll just leave it like it is and look into getting a different headset (have my eyes set on a pair of Plantronics GameCom 388). Hopefully I won't run into the same kind of trouble as with these Zalmans which I now hold the sole culprit for this ordeal (I could've spent the weekend in more relaxing ways than snooping around my PC to check for loose cables and grounding and stuff).

Again, thank you very much for your answers and time. If anything else comes up related to this, I'll post an update here.