I have a setup which is Laptop/PS4 -> Topping E30 -> Schiit Asgard 2 -> Beyer DT990. And, when the volume on the Asgard goes to a third or more, there’s a buzz. Is there something obvious I can do to track it down?

My challenge is that I have a lot of electronic kit in the vicinity- it’s my home working location, so there’s a lot of stuff plugged in like two monitors, a printer etc. For practical reasons it needs to stay, but is there something I can do to easily eliminate the buzz? Not an expert, but it doesn’t sound like a 50Hz mains hum you’d get in the UK.