The John Mayer Signature Strats may look similar to most other strats, but they do have some important differences. The neck is a more chunky “C” shape that most, which helps to give the guitar a fatter tone and better sustain. The guitars also boast John Mayer’s custom-spec “Big Dipper” pickups – which are exclusive to his guitar. The story goes that on his original SRV signature Strat, the pickups had been would incorrectly, resulting in a “scooped” (or lower) mid-range output. On an EQ curve, this would look like an inverted bell shape, where the mid-range frequencies dip down, hence the name “Big Dipper”.
There was quite a bit of controversy in 2010 as the Custom Shop worked on the 83 TBO models, as people wondered what kind of pickups were in THAT particular guitar. The spec sheet that came out only said “special pickups”, but after much pressure, Custom Shop marketing director Mike Eldred divulged that it too had Big Dipper spec pickups, only that they were wound by the Custom Shop.