Abstract: Slotted bobbins consisting of a plurality of wire coils, are secured within a pickup for a stringed instrument assembly having an upper plate with a plurality of slots running in the direction of the strings, the slots of the bobbins being aligned with those of the upper plate. A magnetic pole piece is slidably disposed within each slot, each pole piece being independently slidable along the length of its slot, to allow reading each string at a different spectrum. The pole pieces are releasably secured within the slots so that they can be set at a desired point prior to playing of the instrument.