Locomotives with 21-pin decoders sometimes require a different approach to connecting a speaker. MIKE WILD explains all with Kernow Model Rail Centre’s ‘OO’ gauge model of the D600 ‘Warship’ diesel-hydraulic.
Above: D602 Bulldog roars out of the tunnels on Topley Dale with a rake of BR Western Region chocolate and cream liveried Mk 1s in tow. The Wheeltapper Sounds audio project brings realism to the driving experience through its functions.
THE KERNOW MODEL RAIL CENTRE Class 41 North British A1A-A1A ‘Warship’ is a simple project for a sound upgrade and highlights a common format you will come across in many ready-to-run locomotives.
It is fitted with a 21-pin decoder socket which offers great connectivity to additional functions without the need for trailing wires via its higher number of pins. It also means that we don’t need the speaker wires connected to the decoder anymore as virtually all current ready-to-run locomotives with a 21-pin decoder socket have traces to solder pads on the main Printed Circuit Board (PCB) to allow for connection of a speaker. There are a couple of exceptions to that rule from the Heljan roster including the Gresley ‘O2’ 2-8-0 which has been designed to work with ESU 21…