in 1964 Fender changed from using formvar wire to enamel wire which gives the Strat a very mid scooped tone. In 1965 for one year only they changed to polysol wire which gives the Strat a very pronounced midrange and an upper midrange squawk. in 1966 and subsequent years Fender switched back to enamel wire. I agree with the consensus that any Strat pickup with enamel wire will get you Hendrix tone for days. In my opinion a 1966 Stratocaster specifically renders that "Wind Cries Mary" tone. It has a scooped mid sound, it is dark and yet has pronounced highs.