New server causing weird noise in headphones and speakers; Is this electromagnetic interference? What's causing it?

Solution 1:

I've been a systems administrator for a TV+radio station a few years ago, and I also had lots and lots of analogue broadcasting units in my server room.

What I did was to make sure that every single piece of broadcasting equipment was properly grounded. I got an electrician to run a new, isolated ground feed to the server room, which I then terminated at the overhead cable guides (metal). I then ran ground cables from the cable guide down to each rack cabinet. I also had a online UPS which filtered any kind of voltage jumps.

It's also important to make sure that the equipment in the other end is grounded.

Solution 2:

It does seem like it is EMI. Your use case is quite unusual so it's unlikely many people will have encountered it.

As you have determined that it is the new server that is causing the problem by the simple expedient of turning it of and on then (I'm guessing you have no support) you're going to have to diagnose the hardware yourself.

If you have other 1950's you could try swaping modules from one to the other. Failing that you're kind of stuck.