Kit: MX648, YouChoos IceCube25X18X06-1W speaker, SACC16 with SuperCap17000

Our donor model is this 2019 Hornby J36, weathered and detailed by TMC...

It was supplied with a DCC Concepts Zen decoder, but no matter what we did, it would not control the motor properly, stopping and starting seemingly at random. We removed all the interference suppression components and still no better, so came to the conclusion the the Zen decoder was faulty, or the model drew too much power for it. Tested with a Zimo MX600R and all was fine.

In any case, we want sound, and the requirement was with stay-alive as this model will be used on an exhibtion layout (Bentley MRC, Wiltshire). So out with the 8pin socket, join loco pickup wires with tender pickups and connect up an MX648 directly.

Remove surplus wires from the decoder (no lighting wanted on this one), add a wire for GROUND ready for the SACC16 (stay-alive) connection and recover with Kapton tape.

Snip the little SACC16 PCB to minimise it - we will be using a SuperCap17000uF rather than on-board Tantalums capacitors. Joining up the decoder's common positive (BLUE) and the freshly added GROUND wire (we used a grey wire for this).

Add wires from the SACC16 to the SuperCap (we quite like using red and black for this to show +VE and -VE). Cover the SACC16 with Kapton tape too.

Decoder and SACC16 fit neatly underneath the metal weight, secured with a little blob or two of Black Tack, and teh SuperCap sits about half-way along the weight just before the main slope of the coal load. Mount the SuperCap on electrical tape and stick securely down.

A YouChoos IceCube speaker (25x18x6mm) is perfect for the back of the tender. Anything deeper won't go, but this will give a great sound. Put electical tape over the back of the metal weight to ensure that the speaker won't short on it.

Tender top back on, and running sweetly.

Photo shoot time...

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.