I have my computer in the corner of the room for this reason. Noise gate will help but it will mask it and really chuggy palm riffs will make the whistling sound come back.
aside from relocating your computer, I’ve found that pointing your guitar a different direction can make it go away. Major pain in the ass. Fluence Moderns are much cleaner when presented with this issue, but just like with the noise gate, it will whistle a bit on palm mutes or other situations.
another thing to watch lit for: any kind of power supply! I had a random usb hub that make a high pitched squeal that my pickups would.. pick up the noise. An absolute nightmare when doing final tracking.
If you need to fix DI’s that have the issue: Izotope RX8
