I made a ribbon mic using chewing gum wrapping as the ribbon (5mm wide). The motor is made from plexi glass and holds two neodym (N42) magnets (40x10x5mm). The DIY 1:36 toroidal transformer with a nano-amorphous ring core is hand wound with enamelled copper wire (216 turns) and enamelled copper wire (6 turns folded). Some good sources if you want to build one yourself: