Crossover Type SP1144

Schematic for the Ref 103.2 crossover, minus the protection circuitry.

Circuit diagram provided by Steve Bell ( on Saturday 3 January 2004

Note below from Colin Royle 11 February 2004

Later models of Ref. 101 & 103-2 that have binding posts have their bases glued in position and the circuit board is held in place with a double sided product from 3M. This 3M product was a spin off from a military application, so it does not unglue easily and because of the small space around the circuit board in the cabinet I would not recommend its removal unless the unit is being scrapped.

On Sunday 10 April 2005 Colin Royle supplied a photo of a late circuit board (SN243xx) from a Ref 103-2. The two red elements in the photo are the transistor and diode packs embedded in a black brick in earlier incarnations.