gold foil pups are a catch phrase these days that has everything to do with look, and little to do with whats under the cover. the original 50s models were bright and very low output, typically a bar magnet adjacent to the coil, with either pole pieces or a steel bar bringing the magnetism to the coil. weird and cheap to produce design but it does have a certain tone to it. modern ones can be almost anything as long as they have the gold foil look
