Solving GPU noise hum/buzz in external USB audio interfaces

[mohragk]

This post is to provide a solution for anybody who is experiencing noise in their audio interface/powered speakers, caused by a GPU. 

 

After building my new PC, a Ryzen 7 3700x with GTX 1070 card and hooking up my Yamaha HS80m active monitors via a Scarlett 2i2 2nd gen audio interface, a loud, very noticable noise was heard in my right channel speaker. Especially when doing GPU intensive tasks, a loud 60 Hz (refresh rate) buzzing was eminating from my beloved monitors.

Reading up on the issue, many solutions were provided, including:

- Making sure every device is connected to the same power socket via a single expansion brick

- Trying every possible USB connection configuration

- Ground lifting the PC (NOT RECOMMENDED)

 

Attempting most of these solutions didn't reduce my noise issue at all. Depressed about my new system not being as awesome as it should be, I began some deep diving into the issue until I stumbled upon a proper solution: ground loop isolation.

See, the problem that caused these noise problems has to do with a loop in the ground path of the system (or so I understand). Normally, a circuit is a closed loop with a DC or AC power source going to ground. But, when multiple devices are (incorrectly) connected to each other, a ground loop can occur. This causes interference signals to travel on unwanted paths, infiltrating the sound stage of a system.

 

Anyway, the solution I would highly recommend for people experiencing the same issue is to buy a ground loop isolator. This device breaks a ground loop in the audio signal path and thereby eliminates any noise or hum. I used a Behringer HD400 Hum Destroyer, but other solutions include the ART DTI ground loop isolator and Morley Ebtech Hum Eli­mi­nator 2.

Another solution is to look at USB galvanic isolators or optocouplers. These break the ground loop on the USB side. A powered hub can provide the same disconnection, so is a great alternative.

[ShearMe]

Another good option is to use an external DAC with an optical input when connecting to a PC. I avoid USB DACs with external power for fear of ground loops.

[mohragk]

20 hours ago, ShearMe said:

Another good option is to use an external DAC with an optical input when connecting to a PC. I avoid USB DACs with external power for fear of ground loops.

Also a viable option, although only if you use a DAC 'one directional'. If you need to have an audio interface for recording for instance, than most options are connected via USB.