The second series EB3 schematic applies to EB3s from late 1971 until 1979. In general series 2 circuitry can be identified by the black cylindrical choke - identical to the one employed on the Ripper, and new-style capacitors.
Pots used were initailly two 500K volume pots (unknown taper) (part 70027) and two 250K audio taper tone pots part 70021. These were the pots listed in the 1971 and 1977 parts lists. The 1981 parts list changes these to 300K (linear/special audio taper) 70028 volume pots and 100K audio 70035 tone pots. In each case capacitor and choke values are unchanged.
These part lists (and instruments examined) clearly differ from the schematic shown (300K volume, 250K tone), and it is probable that all three circuit variants exist, and furthermore the precise potentiometer values are not terribly significant in the operation of this circuit, as long as they are matched.
The image shown below shows a very early series 2 schematic, from an early 1972 EB3, with two 70027 and two 70021 pots
See the series 1 EB3 schematic
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