Model Rail OO J70 Tram Engine with Zimo MS sound and stay-alive

Kit: MS490N; StickyGasket15X11mm speaker; 2x 470uF Flat Tantalums

Revisiting the J70 model here to see what kit makes sense with the MS range of Zimo sound decoders - hopefully a little easier than with MX.

Remove the blanking plate and stick some Kapton tape along the model's PCB so that our decoder cannot short-circuit onto anything on the board.

Note that we've already changed the factory speaker for one of our own 15x11mm StickyGaskets, as these will perform better, and are the same size. The MS490N's speaker wires are soldered to the outer pads on the model's PCB for speaker connection.

Note the blue and grey wires from the decoder, which will be for stay-alive.

Decoder protected in Kapton tape and plugged in - length is comfortable, so definitely an improvement over the MX649N option.

The MS490 can have up to 1000uF 16V stay-alive attached directly with no additional components, and this should be just enough to improve the running qualities of this little loco. We join 2x 470uF Flat Tantalums in parallel and connect to the blue and grey wires from the decoder.

Protect the Tantalums with Kapton, and stick on top of the decoder. There is plenty of vertical space in the body for this combination.

Tested, body reattached, and running nicely!

Please note that these guides are provided as useful resources for you, as-is. YouChoos cannot be held responsible for errors in the information, or for any damage caused to your models or equipment if you choose to follow any of the steps detailed here.