Example 1 - Hornby OO 9F Crosti with simple Zimo sound in tender

Kit: MX645R; YLR302815; 2200uF electrolytic capacitor

Hornby's Crosti variant of the 9F lends itself nicely to a couple of approaches for DCC sound. In this first example, which has the 8pin socket in the tender, we go for a simple installation.

Metal weights removed, there is acres of space for our big YLR302815 2W 8 ohm speaker. We have to trin the screw-mounting lugs off the speaker, but easy enough.

MX645 decoder diagonally at the front, chunky (but cheap!) 2200uF electrolytic at the rear, with a little BlackTack to keep it all in place.

Example 2 - Reworked kit into loco, with 2nd speaker, SuperCap and lighting

Kit: MX645R: YLR302815 + SugarCube10; SuperCap17000uF; Firebox LED; 2x lamps

Now for something a little more involved, but with many more features... we can reuse the 4pin connector between loco and tender, 2 for pickups (the same), and the other 2 (which were for motor) we'll re-purpose for the tender speaker. The rest of the kit to go in the loco, which gives us the option of lighting.

In the tender, we remove the orange and grey wires from the socket, which were for motor, and use this to attach the YLR302815 in the tender.

We need to intercept the pickup wires inside the loco, and as these are not exposed, we have to remove the keeper-plate and solder fresh wires to the pickup strip - red and black - and feed these up through the holes provided - this is the neatest way to do it.

We possibly don't need to do this, but just to ease space constraints, we modify the front motor worm housing to remove the screw mounts.

Preparation for the firebox LED is done by drilling a 2mm hole, then thinning the plastic behind the hole so that the LED can sit close to the aperture, thus revealing the light more effectively. An SMD orange LED is glued to the hole, ensuring that the lighting element of the LED is central in the hole.

We also add a horizontal mount yellow lamp to the top of the boiler door, and a vertical yellow on the right side of the buffer beam, which we'll connect to separate outputs of the decoder for independent control.

Here is the decoder, speaker and SuperCap ready to go in. The speaker tucks right at the front, held with some BlackTack, then SuperCap and MX645 follow it into the boiler. Wiring for the lamps and firebox glow is connected up (with a resistor for each), and the pickup wires (red and black) are joined to the fresh wires we added to the model earlier. The speaker is joined in parallel with the wires to the tender speaker, then just neatly close it all up and off we go!

The finished model does sound great with the dual speakers and lighting!

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.