I'm looking for some help in tracking down the source of a persistent audio issue I am having. There is a very faint but continuous hum being transmitted through my audio devices. The tone and pitch changes depending in what I am doing; moving the mouse, dragging windows, etc. It changes depending on the program, for example dragging a Firefox window makes a different sound from Chrome. It also changes depending on what type of mouse I use; wired or wireless.
Windows System volume does nothing to this issue but when using speakers with their own volume control, keeping that dialed back can mask the issue. This doesn't work for headphones, headsets, or IEM/earbuds due to them not having built in volume controls, so the artifact is always at its loudest, the same as when the speaker is at max.
Even having an audio device connected, powered on but muted and/or disabled as a playback device, will produce this hum.
The audio devices I have used are: Apple Earbuds, Steelseries Flux Headset, an unbranded battery powered portable speaker and Harmon Kardon HK395 Dell 7E840 set. The Harmon Kardon set has its own power cord. They all used a standard 3.5mm audio jack. None are USB powered.
The mice I have used are: Logitech G602 (Wireless USB), EVGA Torq X5L (Wired USB), Corsair Scimitar (Wired USB), an old Dell mouse (PS/2)
When using the Logitech wireless mouse the hum is almost inaudible compared to the others. I suspect that this problem has gone unnoticed for a long period of time, perhaps from the day I built it, because I used that mouse exclusively for years.
I have tested all these devices with a Macbook Pro 2010, and found no abnormalities.
Other steps I have taken in trying to isolate the issue.
- Removing and updating the Realtek audio driver
- Tested both the front and rear analog audio out
- Tested all USB 2.0/3.0 ports on the case and motherboard IO
- Updating the UEFI
- Replacing the PSU
- Removed the GPU
- Booting into Windows Safe Mode
- Disconnecting my drives and booting off a live fresh install of the latest version of Kali Linux using a USB stick
- Testing each DIMM slot
- Testing each stick of RAM separately
- Testing to see if modifying the RAM frequency would cause a change
- Testing to see if modifying the CPU frequency would cause a change
- Tested the motherboard outside of the case.
- Running Intel's CPU diagnostic (No issues found)
- Testing multiple power outlets and multiple power stripes in different locations within my home.
- Using a ground lifter to see if it was a grounding issue
*I may have forgotten a step or two that took in my testing.
After doing all to these things I contacted my motherboard manufacturer, ASRock, believing it to be an issue with the onboard sound of my Z87 Extreme6. They agreed to a RMA and two weeks later (7.5.2016) my replacement board (not new) arrived. After rebuilding the computer I found that I still had the same issues present and so I went through my list of tests again. There were no changes until I tried the following.
I recently bought a Blue Yeti microphone and during my testing, found that plugging my audio devices into the audio out of the mic would eliminate humming. I don't know exactly why it does this but I expect it is because the mic has its own built in AMP and DAC. This is really only a temporary solution though, one that I only happened to have on hand.
I know this is quite a long post and thank you for reading all of it. I am also in continued contact with ASRock, trying to find a source and resolution to this problem. However, so far I’ve had little success. Hopefully, someone at Intel can shed some light on what the cause of this hum is or what component in my system is failing.
OS: Windows 10 64-bit
CPU: Intel Core i7 4770K BX80646I74770K
MOBO: Z87 Extreme6
RAM: G.SKILL Ares Series 16GBF3-1866C10D-16GAB
GPU: EVGA GeForce GTX 770 02G-P4-2774-KR,PCIE
SSD: Samsung 840 Pro 256GB MZ-7PD256BW,SATA
PSU: PSU: Corsair HX 850
Realtek driver: ver. 18.104.22.16860
GeForce Driver: ver. 364.72