Dapol N gauge Class 50 diesel with Next 18 DCC Sound

Kit: MX658N18 or MS580N18; YouChoos Custom Dapol CL50 SugarCube speaker

Dapol's 2019 N gauge Class 50 model is pretty simple to add sound into... either the MX659N18 or MX658N18 will fit, but we recommend the larger MX658N18 simply because it has a little more on-board stay-alive. The MS580 supercedes the MX658, so that is the newer one from the MS to use.

Here's the model to begin with, body popped off reveals the Next18 blanking plate and a floating enclosure for a StickyGasket 15x11mm speaker provided.

For comparison, we show the MX659N18 (smaller decoder) and MX658N18 (longer):

The supplied speaker enclosure takes a 15x11mm component speaker - our StickyGasket speaker will fit, but is harder to get a really good permanent seal:

This experiment by a customer used our SugarCube7 speaker, with a couple of pieces of material to raise the edges so as not to catch on the drive-shaft, and works really well with improved sound:

(above photos supplied courtesy of Rupert Anderton)

Due to these findings, we have developed a custom 3D-printed speaker especially for the Class 50, which is based on a SugarCube8 depth, but with space for the drive-shaft (see below next example). It fits OK with both the refurbished and unrefurbished models with the cut-out vent on the roof).

Here is the MX658N18 and Custom speaker...

First, a quick photo with the body removed - blanking plate is still plugged in, and the original factory speaker box is also shown.

MX658N18 now plugged in, and we have to unscrew the factory PCB in order to take out the original speaker enclosure - it doesn't fit up through the apperture in the PCB!

Our new SugarCube-based Custom speaker will be held in with some double-sided sticky tape - a thin piece on either side...

It just pops through the hole - gently press to get the sticky tape to adhere.

2 short lengths of fine decoder wire to connect the speaker terminals to the speaker solder pads on the board (marked 'LS')...

Dapol have pushed the boat out with the lighting... there are normally only 4 function outputs on a Next18 decoder with full power outputs, but we need 6 for this model (2 for whites, 2 for reds and 2 for cab lights). The extra 2 (for the cab lights) make use of the Zimo's combination pins that can be switched between logic-level (low voltage) outputs and SUSI connections. This caught us out to begin with, but switching on bit7 in CV#124 achieves this. That CV is for MX only... on MS you need to set CV#201=11 to make FA3/4 logic-level outputs instead of SUSI.

We decide to use the following FKeys for the lighting:
- FKey0=directional white lights
- FKey6=Directional red lights
- FKey12=Directional cab lights
To get this we make some CV changes (this is the immersiveDrive version):
- CV#33=1 (FKey0 in FWD direction gives F0Fwd output for front whites)
- CV#34=4 (FKey0 in REV direction gives FA2 output for rear whites)
- CV#40=10 (FKey6 gives F0Rev and FA1 for the red lights)
- CV#46=48 (gives FKey12 for both cab lights)
- CV#125=1 (F0Fwd only in FWD only)
- CV#126=2 (F0Rev on in REV only)
- CV#127=2 (FA1 on in REV only)
- CV#128=1 (FA2 on in FWD only)
- CV#129=2 (FA3 on in REV only)
- CV#130=1 (FA4 on in FWD only)

Ensure the switches are appropriate for a 6-function decoder, with cab lights operating on their own FKey:
- SW1 to the centre (front cab light works on FA4)
- SW2 to the centre (rear cab light works on FA3)
- SW3 down
- SW4 up (on)
- SW5 up (on)

The roof panel lifts out neatly, which is a nice touch, giving access to the switches that control the cab lights.

...and the model in all its' glory... with a couple more of his friends!

Example 2: MS580 decoder

Below is another Dapol Class 50, this time fitted with an MS580N18 decoder instead of the older MX equivalent. Otherwise, the install is identical.

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.