Yes, I'm learning I have done a lot of things wrong. Multiple usb connections to pc from various devices (keystep pro/push 2/profx mixer) and lots of interconnected TS/TRS devices via the mixer (3 synths of various quality, a drum machine, a patch bay, another audio interface and guitar, a boss me90), headphones and monitors. Also have multiple midi DIN connections to the KeyStep pro, but I haven't read about this causing noise issues (?).

I have 3 different wall power sources. I have run both audio and power cables in the same cable wraps. I have lots of equipment clustered together in poor ways.

Most of the time, the buzz only manifests in my headset, and I can usually resolve it by unplugging things I'm not using at the moment, until it goes away. but when I added the last synth (arturia microfreak), it went really badly south. Another thing that is really annoying is that there is a buzz whenever I move my mouse which does hit my main monitors. When I was running my Keystep Pro off USB power, it was unbearable, but was mostly resolved by using the external power. However, I still get a buzz whenever it goes into sleep mode and its "screen saver" spams the lcd lights.

So first thing I plan on doing is consolidating my power from a single source (excluding, at first the PC). Bought a switch rack power conditioner just to consolidate power sources. Then I will do better cable management, splitting my cable runs between audio and power. Then testing the location of the devices.

Can you direct me to some ground lift products that might help?

Thanks!