Kit: Zimo MX649 hard-wired and MicroCube6 speaker
The model before we start, and then with the bogies popped out and 4 retaining screws removed.
It is a neat design for simple DCC install, with the cab sliding up and off. However, to get DCC Sound in there, we have a bit
more to do!
Very carefully remove the body/frame from chassis (quite tricky at the cab end so be very gentle and patient). Remove the
battery box from underneath too. We had to remove the steps from each corner too.
As an experiment, I first attempted a 6pin direct plug in MX649N, with the pins trimmed and soldered directly to the model's
PCB. I've seen this done elsewhere, but I found it so tight that to squeeze the cab back on afterwards was just too tight and
the potential for short-circuit or mechanical damage was rather high, so I've opted for a safer route, albeit with a little
So here, the restarted effort, removing most of the factory PCB, just retaining enough for the pickup screws and for the front
lighting board to remain. It does mean some careful rewiring of the lights, particularly where the resistors are, but there is
so much more space for this approach that I felt it was a much more sensible way to go.
Here we have the MX649 hard-wired with motor wires direct to motor terminals, pickups direct to the screw rings, and lighting
directly to the lighting boards, but with some modifications to ensure that resistors are en-route to every LED.
Our speaker is a YouChoos MicroCube6, but a MicroCube5 would be easier, or a MicroCube7 might even go in, or a Zimo MicroCube
with reduced enclosure would also work very well.
Note the yellow wire to the cab lighting board - it goes via a new resistor, and we've cut a couple of the tracks to make this
work. It is an odd design from the factory because the yellow LEDs are protected by a resistor on the lighting board, but the
red LEDs are protected by one on the main PCB. Similar for the front lights.
The finished article!
Kit: MX660; MicroCube5
A different approach to the Farish 20 is to use Zimo's drop-in sound decoder, the MX660. It turns out that this is almost the
perfect size for this model, though does still require some very careful modification and soldering. Speaker is similar to the
previous example - MicroCube in the cab.
Noted here the portion of the factory PCB that will need to be removed.
Small platforms are added to the plastic braces to raise the MX660 off the chassis.
Motor wires are attached directly.
This picture shows the MX660 in position - just needing to connect all the wires up - quite a lot of them including the
lighting, so fine decoder wire and careful soldering required!
Testing motion with just the motor and pickups connected to start with...
Photos for this example kindly supplied by Arthur Frost.