Power Plant 10 noise

The P10 does not have a fan. My P10 does, on occasion, mechanically hum. While I have not absolutely confirmed it, my thought is it is DC on the powerline. I’m in the U.S., not sure if DC is a problem in the UK, but I just live with it. The other possibility is the transformer has loosened. You might be able to check this by trying to spin the “bolt” on the bottom plate. More likely you will have to open it up. Here’s a link to a forum thread on removing the top. There may be other threads that discuss this better, but this one came up first.