Kit: MS500; SugarCube7; 2x 470uF Flat Tantalums
With the advent of the Zimo MS Sound decoder range becoming available, we thought we'd revisit our DJM 14XX sound installation
approach. The little MS500N looks good as a simple plug-in, so should be a much easier kit to put in.
Our example model already has a working lamp on the front, but that doesn't change anything else about the approach.
The tiny new MS500N does fit in OK, though it is easier with the shrink wrap removed, as it makes it thinner - recover in
Kapton tape if you want to do this, to avoid any short-circuits with the PCB in the model.
However, the other benefit of going with this little decoder is that we can add a small amount of stay-alive directly, and this
model really would benefit from it! We therefore ensure that the appropriate wires are added for this purpose (blue and grey
At the bunker-end, the SugarCube7 is the easy option. Usual issue though is to take care with the cab doors when you remove
the roof, as they just pop out and are a bit fiddly to get back in as the roof goes back down!
Back to the front end again, the MS500N is plugged in. We test-fit it into the boiler, which just about goes in OK, but is
tighter than we expected. It looks like it is going to be very hard to get the Tantalum capacitors in for the stay-alive too!
A pair of 470uF Flat Tantalums (16V) are joined in parallel. We can connect up to 1000uF total direct to the MS500 without the
need for any extra components.
Everything is now wired up, but try as we might, we just cannot get this all to fit in the boiler! The MS500 is quite delicate,
due to its' tiny size, so we don't want to force anything too hard.
The solution is therefore to lose the 6pin socket board PCB from the board, and convert or swap the MS500N to a wired version
instead. Some very careful soldering required to transfer the wires, but this all fits much more comfortably, and the result is
a DJM 14XX that finally doesn't stall every quarter rotation!
So, in conclusion, the MS500 (wired version) does make it possible to include a worthwhile stay-alive in this model, but it is
not an install for the faint-hearted - the soldering is delicate and fiddly, but at least we know we can make the 14XX work