Experimenting with Electronics (April 1998): The voltage converter circuits shown in Fig.4 and Fig.5 (pages 28 and 29) show the BC327/337 output transistors in a rather self-destructive configuration. Their positions should be swapped so the BC337 collectors connect to the positive rail (+9V) and BC327 collectors are tied to ground, with their emitters joined at the output - a standard emitter-follower, push-pull configuration.