Looking for a sound decoder?

No matter what scale you model there are several factors to consider when deciding which sound decoder to purchase. First you need to see if anyone actually makes a decoder that will fit, especially if you model in Z or N scale. With the introduction of sugar cube speakers there are more models in which sound installation may be possible. The main limitation really is a matter of whether there is a decoder that will fit. While sound decoders will fit in many N scale steam locomotive tenders, many diesels remain a challenge. Streamlined Backshop (www.sbs4dcc.com) has a fairly comprehensive list of decoders for various scales.

There is a much wider selection of sound decoders available for HO scale and larger models, and installation is generally easier. Many manufacturers offer plug and play versions of their decoders that may only require plugging in the decoder, installing a speaker, and hitting the tracks. TCS offers kits containing their WOWSound decoder, a motherboard, speaker, and speaker enclosure designed for specific locomotive models. These are a great option for anyone who has never installed a sound decoder and practically guarantee a perfect fit.

At one time stall currents were a concern when selecting a decoder. However most models made today have very efficient motors that draw under 1/2 amp and most decoders now can safely provide 1 amp operating current. If you have older motors made before about the year 2000 it is a good idea to see how much current it draws. As a guide open frame motors generally draw more current than can motors.

The final concern is whether or not the available decoders actually offer the sounds package you need for a given locomotive. On their website Soundtraxx has a great page listing many of the types of steam and diesel locomotives and the proper sound package for them. There is a listing of the various prime movers used in diesel locomotives and an excellent one on the types of horns many railroads used. Digitrax, Loksound, Soundtraxx, and TCS all have pages on their websites where you can listen to clips of the sound packages they offer. So finding the right decoder is mainly a matter of doing a little research.


  • Excellent post Larry, I have only one thing to add.
    If you can, like if your just getting into sound, Stay with the same brand of decoder. if possible. The exception might be if you are using a lot of decoders with only two extra out puts, which might be just fine for most diesels, then you get say a steam loco, and you want to use all the features available. Then you would need something with more than than four outputs.

    There’s something else to consider also. I found out the expensive way, that not all outputs are accessible with some older throttles, such as the Digitrax DT 400. I had to upgrade to the newer DT500 series to be able to access some of the functions on my economi decoders.
    Of course I also had to get a newer radio receiver that was compatible with the new DT500.

  • Thanks, Larry. Other than speaking directly with decoder manufacturer’s senior engineers, you are “The Man” for reliable/dependable advice!

  • Larry

    Having said, “At one time stall currents were a concern when selecting a decoder. However most models made today have very efficient motors that draw under 1/2 amp and most decoders now can safely provide 1 amp operating current”, what is your opinion about using an “unmatched” sound decoder in a loco (for example: using an N-scale sound decoder in a HO-scale loco)?

    Would there be any “hidden” disadvantages?




    • Other than those N scale decoders designed for a specific type of model, called drop in or plug and play decoders, there really should be no difference between decoders. The Z, N, and HO designations were created back in the good old days due to size differences as well as amperage rating. An Econami or Tsunami2, for example are the same size as some fo the older N scale decoders. When selecting a decoder just make sure that you don’t accidentally pick up something that is rated at an unusually low amperage. For example the small LokSound select decoders are rated at 0.75 amps so don’t use one with a loco having a stall current around 1 amp. As I said though, most HO scale locos now only draw about 0.5 amps. Hope that answers your question—Larry