Comment by faidit
Drone Zone on SomaFM (free internet radio) was how I discovered a lot of that stuff. Although they don't play the old classics as much these days, it's still good and they have a few similar stations there https://somafm.com/player24/station/dronezone
I generally find Deep Space One more appropriate for most of my coding, though I used Drone Zone a lot many years ago.
I've been supporting SomaFM for more than 20 years now, and am so grateful for it. Not just the ambient stuff, but Secret Agent and several others too.