This article describes the process of fitting DCC sound to a Hornby class 50 locomotive.
The Hornby class 50 is a really easy model to fit sound to and takes about 10 to 15 minutes to complete.
My sound decoder of choice is the excellent ESU Loksound:
These decoders are a single package, combining traction control with 4 functions and sound. They are back-EMF decoders and provide excellent control. Because the decoders integrate traction and sound, the sound is properly synchronised with the motor operation.
The ESU decoders come supplied with a speaker and a baffle box into which the speaker fits. Wherever possible, I try to fit the larger ESU 40x20mm speaker as this gives better sound reproduction.
The Hornby class 50 is a 'DCC ready' loco - it has an 8 pin DCC socket with a blanking plug fitted. This plug needs to be removed.
The first thing which needs to be done is to create space for the speaker. I chose to remove the fan mechanism as follows:
The only modification necessary is then to remove the little nodules which retained the fan mechanism so that the new speaker can sit flush with the frames. The nodules can be seen sticking up from the frame:
Other than soldering a suitable speaker, there is no wiring to be done in this loco - simply plug the decoder in and locate the speaker:
The first picture shows the decoder and speaker temporarily in place. The second and third pictures show the new 20x40mm speaker in place and everything retained with insulating tape.
Sound is not very effective unless it is allowed to 'escape' the loco, otherwise it is 'caught' inside the model, reverberates and can create strange noises in the bodywork which are not heard on the prototype.
The Hornby class 50 already has a mesh fan grill which does not require any modification. The speaker is located directly beneath the grill.
Results - The Model in Action
Class 50 - at speed