Question Microphone buzz issue or/and recommendation

[noob25002]

Hello,

Having an issue with a low frequency buzz when using a microphone.
TUF B360-PLUS GAMING (Realtek ALC887), Seasonic 620 Bronze, Xonar DGX, Windows 10 x64. For microphone I tried a Zalman ZM-MIC1, some generic headset with a microphone, and hands free headset.

Tested all 3 microphones on a phone, and there was no buzz.

If I grab the microphone in my hand, the buzzing increases.
Tried attaching the PC to a UPS, no change.
Also tried Unix drivers, on board sound card with the DGX removed, as well as the planar HDD"s disconnected.
Removed power cable from monitor.
The extension cord has just the monitor and the PC.

On the onboard card the buzzing was lower, but so was the volume. Tried the effects/settings of the onboard card to reduce the issue, no change.
On the DGX decreasing the microphone volume reduced the buzzing, but where it went away the microphone was too quiet.

What would be the cheapest solution? I understand that USB microphones can also buzz, because of lack of shielding?
Ideally I would prefer an attachable type, like Antlion models. I see they have a USB one. I'd like to attach them to headphones, which are comfortable and would like to keep (HD380Pro).
Or should I go for an external USB card, which would be connected to a microphone?

With monitoring on, the buzzing can be seen in the graph below:

 

[noob25002]

If I were to get a USB microphone, since it draws it power from the PC, would it still have the buzzing?
Not sure how USB draws power vs. the Xonar via PCI E.

 

[Stuka87]

Buzzing like you describe sounds like a grounding issue. Especially if it gets worse when you touch it.

Another possibility, (but this normally only impacts case headers that have a wire running to them) if you are picking up interference from something that is poorly shielded in the case. But thats normally if the audio wire is running right next to a GPU or a fan.

A USB Mic may solve the issue, but I cannot say for sure without knowing the cause.

 

[noob25002]

Got an Antlion USB. The buzzing is still there, but substantially reduced.
Also got a shielded USB extension cable and some ferrite beads for the USB cable and the power cable, but no change.

 

[FireDragon76]

It could also be due to the power supply. Contrary to frequent myth, noise in the PC is not all down to EMI, in fact I would reckon much of it is not. Power supply ripple can also be a factor, and if you power supply is aging or bad, that also might be a cause.

USB microphones can be decent but it's really better because usually the 5v rail that USB uses for power has much less ripple, usually half that of the 12v rail or less. The noise inside the case is going to be relatively insignificant for your application (gaming), unless the sound device in question is poorly designed. USB mics can also provide more voltage to the microphone than what is typical. Most soundcards and sound chips cheat and use the same voltage for their line-in and mic-in input (often it's just one single jack, indeed). This is poor engineering, as most microphones used by gamers are electret microphones and are actually decent once they get at least 5V to help lift the signal above the noise floor.

 

[Paperdoc]

I'd agree with the poor grounding idea.Many computer system components and their cables have outer shields to prevent the entry of external noise. These basically work by short-circuiting any incoming electromagnetic field through the shield to chassis Ground. BUT that really works only it the CHASSIS is truly grounded so that the faint noise currents have a place to go. We often hear comments on the use of the Ground lead of the PSU's power supply cable to prevent electrical shock from odd power circuits. But we hear much less often about the importance of that same connection to Ground for NOISE reduction. Check how the power cord from the wall to your PC is done. Does the wall outlet truly have a three-slot outlet for the 3-prong plug on your PSU? Has an adapter been used somewhere to allow connecting to an outlet with only two slots and no round Ground hole?