Installing DCC sound

[wymichael]

Hello, I have a Bachmann 4-8-4 "Freedom Train" that has a non-sound DCC decoder. I would like to add sound to it. The decoder has an 8-pin NMRA plug. I'm trying to figure out what would be an appropriate sound decoder to add to it. For instance, the Digitrax SDN144PS decoder has an 8-pin plug. Is it just as easy as matching the number of pins in the plugs? It looks to me like this would work but is there something I'm missing or other issues to consider for compatibility? I'd appreciate any hints or guidance on what would be an appropriate sound decoder for this locomotiive.
Thanks for any help you can offer.
Michael

[Jim Banner]

There is more to it than just matching the number of pins but that is a good start.  There is a bit of soldering to do.  This includes 2 wires to the supplied capacitor, 2 more wires if you use your own speaker instead of the one that comes with the decoder, and a few more if you decide to use the two extra decoder outputs to add some additional lighting features.

Then there is mounting the speaker.  This is an easy job if your tender already has a place to mount the speaker and holes to let the sound out.  It is a bit harder if you have to drill the holes yourself.  For best results, the speaker needs a baffle which is simply a sealed box to keep the sound waves from the back of the speaker from mixing with the sound waves from the front of the speaker.  With steam locomotives, it is usually possible to use the whole tender as a baffle although in some cases you may have to seal up a few openings.

Lastly, the decoder requires some programming.  At a minimum, you will want to change the address from 03 to something else.  To get a better match with your locomotive, you may want to change a number of the CV's which will require using a DCC system capable of programming CV's.  You might even want to change the sound scheme to exactly match a particular 4-8-4 which can be done with special sound loading programs and equipment.  But before doing all that, try the default programming and steam sound scheme that are preloaded into the decoder.

Before proceeding, you may want to read the manual for this decoder.  Don't let it intimidate you.  Rather, look at installation as a series of easy steps.  As for the programming possibilities, it usually helps to be aware of the things a decoder can do.  But it is completely unnecessary to try to remember how to make it do those things.  That is what manuals are for.   The manual can be found at this link:
http://digitrax.com/ftp/SDN144PS.pdf

Jim