I'm in the process of importing a bunch of old schematics from a 70's era synthesizer into KiCAD. In the process I've come across a symbol that I can't make sense of. It looks like this:
Does anyone have an idea of what part this is? The only other IC used in the schematic is an LM741. Could this just be another LM741? Why does it have FET written inside it?
Edit: The schematics are dated December, 1975. So the parts would have to be older than that.