|Ant makes single coil pickup formers from board and magnets.|
Magnetic fields fall away rapidly with distance, and with a moulded plastic bobbin, there is inevitably a gap between the pole piece and the coil. Instead, we made the pickups in the traditional manner, with board and Alnico-V magnets supplied by the mighty StewMac.com. Although it takes a little time to construct the pickup in this manner, this method does give a better sound, as the copper wire coil is wound directly onto the magnets, with the most intimate contact possible.
|The old strat pickup assembly removed|
We made a couple of small tools to help with the assembly. A pair of acrylic blocks were cut to act as spacers between the top and bottom of the pickup, to keep the boards parallel. One of these was drilled to help align the magnets as they were knocked into place. The other tool was a spindle for the coil winder.
|Knocking in the magnets - a strip of wood protects the magnet from the hammer!|
Once the three bobbins are assembled and glued, it is a simple case of winding the required number of turns onto the former without breaking the wire! The neck and mid pickups were wound with 9000 turns of 42 AWG plain enamel copper wire, and the bridge pickup with 9800 turns, which gave DC resistances of 6.7 kΩ and 7.4 kΩ respectively. 7.4kΩ indicates that around 1300 meters of wire has been wound onto the pickup! For comparison, according to Vintage Guitars Info, the original Stratocaster pickups measured circa 5.8 kΩ to 6.3 kΩ.
|An assembled pickup - magnets and flatwork - on the coil winder.|
It was interesting to see how the original pickups were wound - they are pretty inconsistent, and one in particular had substantial asymmetry to the coil. Perhaps there is some magic to this, but we suspect that it was just their winder drifting out of alignment and piling up the wire on one side.
|Fender Stratocaster pickup, circa 1983.|
Our pickups were a bit neater than that! Once wound, the lead wires are soldered on, and the complete pickups are dipped in the wax bath to stop microphonics, and then magnetised. A pair of very powerful 1 inch circular neodynium magnets were used to magnetise the Alnico 5 pole pieces, and we measured around 900 to 1100 gauss for each of the poles. The middle pickup was reverse wound, and given a reverse polarity, by simply flipping the bobbin over for the winding and magnetisation processes. This gives some humbucking when the mid-positions are selected.
The verdict? "Those pickups are PHAT!! Awesome. Loads more bass!"
|Back together again - Stratocaster heaven!|