The Graham Farish N Gauge WD 2-8-0 Austerity - installation guide for DCC sound using Zimo MX648 and SugarCube7 speaker...

Here's our donor before starting work...

4 screws underneath allow us to pop the tender body off, revealing a lot of potential space.

Our intention... to fit a Zimo MX648 sound decoder and YouChoos SugarCube7 speaker. We could probably even get a full-sized 9mm SugarCube in here, but the 7mm is plenty loud enough and bassy enough for N gauge. We remove the DCC socket board.

The unwanted function-related wires have been removed from the decoder for neatness. To create plenty of height, we've cut a rectangule hole beneath the coal load area so the decoder can sit higher up. Unlike many recent Farish tender models, the WD has a pair of solid metal bars where the pickups are connected, including 2 screw-pillars where we can easily attach our decoder's black and red pickup wires. To make this even easier, we can recycle part of the DCC socket board, chopping the 2 screw holes out of it and soldering our black and red wires before screwing into place.

All soldered up, placed in position (thin double-sided sticky tape is great!), electrical tape over the pickup bars, this should go in really easily...

The decoder sits up in the rectangular hole we cut earlier, but not too high.

We could just put the original plastic coal load back in, but the tender is quite low on weight, so we cut a couple of strips of roofing lead, insulate with electrical tape and place those on top of the decoder.

Black-Tak is an excellent material for filling gaps, and has been used to great effect here around the edges of the wrapped lead. With some teasing, an interesting shape can be created for the coal ballast to be attached to.

Some crushed Woodland Scenics Coal Ballast is glued on top and spread to satisfaction.

One of the easiest DCC sound steam fits ever... here's the final result...

Here's another one done a similar way but with a little less cutting of the plastic under the coal load...

Another example here, expands on the idea by adding some stay-alive - our LifeLink PCB and some Tantalum capacitors...

Same starting point, with the speaker hidden at the rear, and the decoder sitting nice and low, there is a lot of room available above for the stay-alive. We go with a LifeLink with 2x 470uF Tantalums, though various combinations of Tantalums would have be possible.

We cut a few pieces of lead to increase the weight of the tender - a couple of pieces is plenty - if you add too much, then tender will cause drag and the engine may slip on inclines and corners!

The lead is wrapped in electrical tape, and BlackTack teased into shape, sealing the aperture. Crushed lump coal is then sprinkled onto some UHU to finish the coal load.

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.