I'd look into stuff like Harold Budd, William Basinski, or Jon Hassell (who in turn influenced Eno; you can hear some similarities but also radical differences because Hassell played processed trumpet and had a much more dense sound palette. Albums like "Fascinoma" or "The Surgeon of the Night Sky Restores Dead Things By he Power of Sound" for starters, but they did one album together in the early 80s called "Possible Musics" worth a listen)