Kit: MX648, Minnow6 speaker, SACC16 with 5x 220uF Tantalums
This is the big brother to Heljan's Class 05 diesel - the vast majority of the model is identical, so not much space for a sound decoder. Speaker
has to go in the cab, but the bonus of the Class 07 is that there is a deep well of space at the rear end where we can insert a stay-alive!
MX648 is carefully wired in place of the original 6pin DCC socket/board, and we add resistors to protect the directional lighting. A Minnow speaker
sits on the cab floor, though we could probably have found other approaches, and perhaps got a SugarCube7 in there instead. Stay-alive goes in
the rear area in the form of a SACC16 kit with some Tantalums on board. Carefully routing the wires of course, and keeping everything neat and flush is
important in this model.
The result is a really nice little diesel, with good running qualities.