From what I can remember of the movie, it features an increasingly isolated loner building or inheriting a machine in his Attic that starts bringing back monsters from outside reality when he turns it on. I think it was from the early 80s and it had a Lovecraftian vibe to it. The movie is like 'The Fly' in that it features a story that slowly descends into dark horror.
Does anyone have any clue what I'm talking about?
I'll try to add more details if I can remember anymore.