This is how it would look if assembled before winding the coils into the bobbins. Note the 8 steel poles (unaged models have 10) in the noise sensing lower bobbin (right) and the 6 special Alnico-5 magnets in the string sensing upper bobbin (left). The 8 or 10 steel poles boost the efficiency of the noise sensing coil by over 200% compared to what alnico magnets would yield, and that means the coil can be less than half the size. Minimizing the lower coil reduces it's adverse affect on the signal to almost zero.